Change search
Refine search result
1 - 39 of 39
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Andersson, Nina
    et al.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Corkery, Robert W.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    Alberius, Peter C. A.
    YKI, Institute for Surface Chemistry, Stockholm, Sweden.
    One-pot synthesis of well ordered mesoporous magnetic carriers2007In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 17, no 26, p. 2700-2705Article in journal (Refereed)
    Abstract [en]

    The facile preparation of a mesoporous magnetic carrier technology is demonstrated. The micron-sized spherical mesostructured particles are prepared using a newly-developed, one-step, combined emulsion and solvent evaporation (ESE) method. The surfactant-templated silica matrix display a well-ordered internal pore architecture. Very limited pore blocking, and only to a limited degree disordered- or worm-like structures are observed, induced by the iron oxide nanoparticles added to provide the superparamagnetic properties.The iron oxide content was precisely controlled, and themagnetic properties were well preserved during the process. Finally we demonstrate the applicability of the magnetically separable mesoporous material as an adsorbent for specific dissolved materials from dilute aqueous solutions.

  • 2.
    Antoni, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malkoch, Michael
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Vamvounis, George
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Daniel
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Nyström, Andreas
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lindgren, Mikael
    Norwegian Univ Sci & Technol, Dept Phys.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Europium confined cyclen dendrimers with photophysically active triazoles2008In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 18, no 22, p. 2545-2554Article in journal (Refereed)
    Abstract [en]

    Dendrimers up to the fourth generation (G1-G4) were successfully synthesized via the efficient copper catalyzed 1,3-dipolar cycloaddition between primary alkynes and azides (CuAAC), also referred to as a click reaction. The synthetic protocol involved the preparation of presynthesized dendron wedges that subsequently were attached to a tetra-valent alkyne functional cyclen core. These constructed structures integrated stable triazole groups "intra-locked'' between the cyclen and dendron wedges. The incorporation of a lanthanide metal ion, europium, into the interior of all cyclen dendrimers was monitored by FT-IR. Interestingly, the photophysical results showed that the proximate triazole not only acts as a stable linker but also as a sensitizers, transferring its singlet-singlet excitation in the ultraviolet region (270-290 nm) to the partially filled luminescent lanthanide 4f shell. An increase of luminescence decay time from the lanthanide D-5(0) -> F-7(2) emission was observed with increasing dendrimer size, indicating that the shielding effect of the dendron wedges is important for the relaxation of the photo-excitation and energy transfer. To the best of our knowledge, this is the first time a set of dendron wedges have successfully been attached to a cyclen metal ion cage via the versatile click reaction. Furthermore, the produced triazoles intra-locked in close proximity to the macrocycle core elucidated an interesting photophysical function.

  • 3. Bhatt, P.
    et al.
    Kanciurzewska, A.
    Carlegrim, E.
    Kapilashrami, Mukes
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Belova, Lyubov M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Rao, K. V.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Fahlman, M.
    Ferromagnetism above room temperature in nickel-tetracyanoethylene thin films2009In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 19, no 36, p. 6610-6615Article in journal (Refereed)
    Abstract [en]

    Room temperature ferromagnetic ordering is reported in Ni-tetracyanoethylene (TCNE) thin films fabricated on Au substrates using physical vapor deposition (PVD) under ultra high vacuum conditions. This technique enables the preparation of very clean films without having any kind of contamination from oxygen-containing species, solvents or precursor molecules. Film stoichiometry was obtained from X-ray photoelectron spectroscopy (XPS) measurements. XPS derived stoichiometry points to a similar to 1 : 2 ratio between Ni and TCNE resulting in Ni(TCNE)(x), x approximate to 2. No evidence of pure Ni metal in the in situ grown films was present in the XPS or the ultraviolet photoelectron spectroscopy (UPS) measurements within the detection limits of the techniques.

  • 4. Björk, Per
    et al.
    Herland, Anna
    Hamedi, Mahiar
    Inganäs, Olle
    Biomolecular nanowires decorated by organic electronic polymers2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 12Article in journal (Refereed)
    Abstract [en]

    We demonstrate the shaping and forming of organic electronic polymers into designer nanostructures using biomacromolecules. In order to create nanowires, nanohelixes and assemblies of these, we coordinate semiconducting or metallic polymers to biomolecular polymers in the form of DNA and misfolded proteins. Optoelectronic and electrochemical devices utilizing these shaped materials are discussed.

  • 5. Carlsson, Daniel O.
    et al.
    Nyström, Gustav
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Nyholm, Leif
    Strømme, Maria
    Electroactive nanofibrillated cellulose aerogel composites with tunable structural and electrochemical properties2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 36, p. 19014-19024Article in journal (Refereed)
    Abstract [en]

    This work presents conductive aerogel composites of nanofibrillated cellulose (NFC) and polypyrrole (PPy) with tunable structural and electrochemical properties. The conductive composites are prepared by chemically polymerizing pyrrole onto TEMPO-oxidized cellulose nanofibers dispersed in water and the various nanostructures are obtained employing different drying methods. Supercritical CO2 drying is shown to generate high porosity aerogel composites with the largest surface area (246 m(2) g(-1)) reported so far for a conducting polymer-paper based material, whereas composites produced by ambient drying attain high density structures with mechanical properties significantly surpassing earlier reported values for cellulose-conducting polymer composites when normalized with respect to the content of reinforcing cellulose (Young's modulus = 0.51 GPa, tensile strength = 10.93 MPa and strain to failure = 2.5%). Electrochemical measurements clearly show that differences in the porosity give rise to dramatic changes in the voltammetric and chronoamperometric behavior of the composites. This indicates that mass transport rate limitations also should be considered, in addition to the presence of a distribution of PPy redox potentials, as an explanation for the shapes of the voltammetric peaks. A specific charge capacity of similar to 220 C g(-1) is obtained for all composites in voltammetric experiments performed at a scan rate of 1 mV s(-1) and this capacity is retained also at scan rates up to 50 mV s(-1) for the high porosity composites. The composites should be applicable as electrodes in structural batteries and as membranes in ion exchange applications requiring exchange membranes of high mechanical integrity or high porosity.

  • 6.
    Dahlstedt, Emma
    et al.
    KTH, Superseded Departments, Chemistry.
    Hellberg, Jonas S. E.
    KTH, Superseded Departments, Chemistry.
    Petoral, R M
    Uvdal, K
    Synthesis of tetrathiafulvalenes suitable for self-assembly applications2004In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 14, no 1, p. 81-85Article in journal (Refereed)
    Abstract [en]

    A series of new tetrathiafulvalenes, with double alkylthiol or alkyldisulfide substitution, have been prepared with a synthetic procedure that allows variation of different substituents. The target compounds 6a-e and 15e-i are sparsely soluble in organic solvents, but TTFs 6d and 15g gave a relatively dense packed monolayer upon exposure to gold surfaces.

  • 7. Grins, J.
    et al.
    Esmaeilzadeh, S.
    Andersson, Magnus
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Morawski, A.
    Synthesis and magnetic susceptibility of the rutile phase MnTaO42000In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 10, no 9, p. 2197-2200Article in journal (Refereed)
    Abstract [en]

    The Mn3+-containing oxide MnTaO4 was synthesized at 1050 degrees C and 2 kbar partial oxygen gas pressure. It has a rutile-type structure, space group P4(2)/mnm, with a = 4.7189(3), c = 2.9843(3) Angstrom, and a statistical distribution of Mn/Ta. The structure was refined by the Rietveld method using both X-ray and neutron powder diffraction. The refinements, and energy-dispersive X-ray microanalysis, indicate that the phase may contain a small amount of Mn4+ and have the actual composition Mn1.08(2)Ta0.92(2)O4. The magnetic susceptibility shows a maximum at 16 K and Curie-Weiss behavior at higher temperatures, with mu(eff) = 5.11(4) mu(B) per Mn atom. The susceptibility is consistent with spin-glass behavior: (i) the temperature at the susceptibility maximum is frequency-dependent and (ii) field cooled and zero-field cooled susceptibility curves differ below the maximum. Neutron powder diffraction data collected at 10 K does not show any sharp magnetic reflections, but a very broad reflection, with a full width at half maximum height of 7 degrees, at a position corresponding to the 100 reflection is seen.

  • 8.
    Hagberg, Daniel
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Marinado, Tannia
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Hagfeldt, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Brinck, Tove
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Linder, Mats
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Jiang, Xiao
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Gabrielsson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Symmetric and Unsymmetric Donor Functionalization. Comparing Structural and Spectral Benefits of Chromophores for Dye Sensitized Solar Cells.2009In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 19, p. 7232-7238Article in journal (Refereed)
    Abstract [en]

     

    A series of organic chromophores have been synthesized in order to investigate the benefits of structural versus spectral properties as well as the absorption properties and solar cell performance when introducing unsymmetrical substituents in the chromophore. Exceptionally high Voc was found for the symmetrical, structural benefited dye, which also gave the best overall solar cell performance.

     

  • 9. Huang, Z. L.
    et al.
    Lei, H.
    Li, N.
    Qiu, Z. R.
    Wang, H. Z.
    Guo, J. D.
    Luo, Yi
    KTH, Superseded Departments, Biotechnology.
    Zhong, Z. P.
    Liu, X. F.
    Zhou, Z. H.
    Novel heterocycle-based organic molecules with two-photon induced blue fluorescent emission2003In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 13, no 4, p. 708-711Article in journal (Refereed)
    Abstract [en]

    Two-photon absorption and two-photon induced blue emission characteristics of a series of heterocycle-based organic molecules are investigated experimentally and by quantum-chemical computations. The molecules consist of a typical A-pi-A' structure, where heterocycle, styryl and formyl groups are employed as A, pi-conjugated and A' moieties, respectively. Experimental results indicate that significant enhancements in the blue emission efficiency and two-photon absorption cross-sections can be achieved by replacing S and O atoms with an N atom in the heterocycle acceptor moiety, which is also supported by the quantum-chemical computations. Additionally, larger two-photon absorption cross-sections can be obtained by choosing appropriate solvents, as indicated by the computations.

  • 10. Kadas, Krisztina
    et al.
    da Costa, Marcio Teles
    Vitos, Levente
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Applied Material Physics.
    Andersson, Yvonne
    Bergman, Anders
    Eriksson, Olle
    On the icosahedral metal-phosphorus coordination in melliniite: a gift from the sky for materials chemistry2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 29, p. 14741-14745Article in journal (Refereed)
    Abstract [en]

    Recently a new mineral, melliniite, was reported from a meteorite sample. This mineral has an ideal chemical composition of (Ni,Fe)(4)P and a crystal structure where the phosphorus atoms are coordinated by twelve nearest neighboring metal atoms. No other phosphide has been reported to have such high metal coordination. Therefore melliniite provides new and important information about the chemical interaction in transition metal chalcogenides and possibly pnictides. We demonstrate here, using first principles theory, that the stability and icosahedral metal-phosphorous coordination of melliniite are due to a balance between covalent Fe-P binding, configurational entropy and a weaker nickel-phosphorus binding, that has only a weak directional dependence.

  • 11. Kerric, Gaelle
    et al.
    Parra, Enrique J.
    Crespo, Gaston A.
    Xavier Rius, F.
    Blondeau, Pascal
    Nanostructured assemblies for ion-sensors: functionalization of multi-wall carbon nanotubes with benzo-18-crown-6 for Pb2+ determination2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 32, p. 16611-16617Article in journal (Refereed)
    Abstract [en]

    The synthesis and full characterization of new hybrid materials, i.e. benzo-18-crown-6 covalently linked to multi-wall carbon nanotubes – incorporating first and second generation dendrimer approaches – are reported here. Furthermore, the benefit of using these new nanostructured assemblies is demonstrated for solid-contact ion-selective sensor configuration. Both selective recognition and ion-to-electron transduction events take place at the same hybrid nanostructured material. Functionalization of multi-wall carbon nanotubes (MWCNTs) plays a key role in the development of such devices not only allowing an improvement of the analytical parameters such as selectivity and stability but also providing simplicity in the manufacturing stages.

  • 12.
    Kochumalayil, Joby
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center BiMaC Innovation.
    Sehaqui, Houssine
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Zhou, Qi
    KTH, School of Biotechnology (BIO), Glycoscience.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Tamarind seed xyloglucan: a thermostable high-performance biopolymer from non-food feedstock2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 21, p. 4321-4327Article in journal (Refereed)
    Abstract [en]

    Polysaccharide biopolymers from renewable resources are of great interest as replacements for petroleum-based polymers since they have lower cradle-to-grave non-renewable energy use and greenhouse gas emissions. Starch is widely used as a packaging material but is based on food resources such as potato or corn, and suffers from high sensitivity to water vapor even under ambient conditions. For the first time, xyloglucan (XG) from tamarind seed waste is explored as an alternative high-performance biopolymer from non-food feedstock. XG is purified, and dissolved in water to cast films. Moisture sorption isotherms, tensile tests and dynamic mechanical thermal analysis are performed. Glycerol plasticization toughening and enzymatic modification (partial removal of galactose in side chains of XG) are attempted as means of modification. XG films show much lower moisture sorption than the amylose component in starches. Stiffness and strength are very high, with considerable ductility and toughness. The thermal stability is exceptionally high and is approaching 250 degrees C. Glycerol plasticization is effective already at 10% glycerol. These observations point towards the potential of XG as a "new'' biopolymer from renewable non-food plant resources for replacement of petroleum-based polymers.

  • 13.
    Leijonmarck, Simon
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Cornell, Ann
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Wågberg, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Fibre Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Single-paper flexible Li-ion battery cells through a paper-making process based on nano-fibrillated cellulose2013In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 1, no 15, p. 4671-4677Article in journal (Refereed)
    Abstract [en]

    Recently, a need for mechanically flexible and strong batteries has arisen to power technical solutions such as active RFID tags and bendable reading devices. In this work, a method for making flexible and strong battery cells, integrated into a single flexible paper structure, is presented. Nano-fibrillated cellulose (NFC) is used both as electrode binder material and as separator material. The battery papers are made through a paper-making type process by sequential filtration of water dispersions containing the battery components. The resulting paper structure is thin, 250 mm, and strong with a strength at break of up to 5.6 MPa when soaked in battery electrolyte. The cycling performances are good with reversible capacities of 146 mA h g(-1) LiFePO4 at C/10 and 101 mA h g(-1) LiFePO4 at 1 C. This corresponds to an energy density of 188 mW h g(-1) of full paper battery at C/10.

  • 14. Li, Ling
    et al.
    Yang, Xichuan
    Zhao, Jianzhang
    Gao, Jiajia
    Hagfeldt, Anders
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Efficient organic dye sensitized solar cells based on modified sulfide/polysulfide electrolyte2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 15, p. 5573-5575Article in journal (Refereed)
    Abstract [en]

    An energy conversion efficiency of up to 5.24% has been attained, under AM 1.5 G illumination for a new dye-sensitized solar cell using TH305, as a low cost organic dye, ((CH3)(4)N)(2)S/((CH3)(4)N)(2)S-2, as an organic electrolyte and CoS as counter electrode.

  • 15. Lin, Meng Meng
    et al.
    Li, Shanghua
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Kim, Hyung-Hwan
    Kim, Hyuck
    Lee, Hyung Bock
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Kim, Do-Kyung
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Complete separation of magnetic nanoparticles via chemical cleavage of dextran by ethylenediamine for intracellular uptake2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 3, p. 444-447Article in journal (Refereed)
    Abstract [en]

    Completely water dispersible and highly monodispersed superparamagnetic iron oxide nanoparticles (SPIONs) were prepared. The surface of SPIONs was modified with dual-crosslinked amine activated dextran (AMD) and chemical cleavage of AMD on SPIONs was carried out by ethylenediamine hydrochloride (EDA). Transmission electron microscopy (TEM) revealed that individual SPIONs were completely separated in water and the average diameter of resulting nanoparticles was 4.4 nm.

  • 16. Liu, Li-Hong
    et al.
    Yan, Mingdi
    Portland State University.
    Functionalization of pristine graphene with perfluorophenyl azides2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 10, p. 3273-3276Article in journal (Refereed)
    Abstract [en]

    In this article, we highlight the recent work on the covalent functionalization of pristine graphene with perfluorophenyl azides (PFPAs). Three approaches were developed where PFPAs were employed to derivatize pristine graphene with well-defined functional groups, to fabricate graphene films and ribbons, and to generate patterned graphene structures by photolithography.

  • 17. Liu, Li-Hong
    et al.
    Zorn, Gilad
    Castner, David G.
    Solanki, Raj
    Lerner, Michael M.
    Yan, Mingdi
    Portland State University.
    A simple and scalable route to wafer-size patterned graphene2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 24, p. 5041-5046Article in journal (Refereed)
    Abstract [en]

    Producing large-scale graphene films with controllable patterns is an essential component of graphene-based nanodevice fabrication. Current methods of graphene pattern preparation involve either high cost, low throughput patterning processes or sophisticated instruments, hindering their large-scale fabrication and practical applications. We report a simple, effective, and reproducible approach for patterning graphene films with controllable feature sizes and shapes. The patterns were generated using a versatile photocoupling chemistry. Features from micrometres to centimetres were fabricated using a conventional photolithography process. This method is simple, general, and applicable to a wide range of substrates including silicon wafers, glass slides, and metal films.

  • 18.
    Liu, Peng
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry. kTH.
    Wang, Linqin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Karlsson, Martin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Hao, Yan
    Uppsala University.
    Gao, Jiajia
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Xu, Bo
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Boschloo, Gerrit
    Uppsala University.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. Dalian University of Technology (DUT), Dalian, China.
    Kloo, Lars
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Applied Physical Chemistry.
    Molecular Engineering of D-π-A Type of Blue Dyes for Highly Efficient Solid State Dye Sensitized Solar Cells by Co-Sensitization2017In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501Article in journal (Refereed)
  • 19. Müller, Christian
    et al.
    Jansson, Ronnie
    Elfwing, Anders
    Askarieh, Glareh
    Karlsson, Roger
    Hamedi, Mahiar
    Linköping University, Sweden.
    Rising, Anna
    Johansson, Jan
    Inganäs, Olle
    Hedhammar, My
    Functionalisation of recombinant spider silk with conjugated polyelectrolytes2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 9Article in journal (Refereed)
    Abstract [en]

    Conjugated polyelectrolytes are demonstrated to permit facile staining of recombinant spider silk fibres. We find that the polyelectrolyte concentration and pH of the staining solution as well as the incubation temperature strongly influence the efficiency of this self-assembly process, which appears to be principally mediated through favourable electrostatic interactions. Thus, depending on the choice of staining conditions as well as the polyelectrolyte, electrically conductive or photoluminescent recombinant silk fibres could be produced. In addition, staining of natural Bombyx mori silk is established, which emphasises the versatility of the here advanced approach to functionalise silk-based materials.

  • 20.
    Ning, Zhijun
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Yuan, Chunze
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Tian, Haining
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Fu, Ying
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Li, Lin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Type-II colloidal quantum dot sensitized solar cells with a thiourea based organic redox couple2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 13, p. 6032-6037Article in journal (Refereed)
    Abstract [en]

    In this paper, one kind of organic electrolyte based on tetramethylthiourea is employed for quantum dot sensitized solar cells (QDSCs). By reducing the impedance between the electrolyte and the counter electrode, the fill factor of such organic electrolyte based QDSCs is significantly improved. It is possible to substantially increase the photovoltage and to reach an efficiency three times higher than that of a commonly used inorganic electrolyte. The light harvesting ability of the organic electrolyte based QDSCs is successfully extended by using type-II QDs, where the adsorption of ZnS gives an additional advantage in further enhancing the stability of the cells. It is observed that core/shell ZnSe/CdS type-II QDs give higher electron injection than CdS/ZnSe QDs, proving that the electron distribution in the QDs is important for the electron extraction. A full working mechanism of the organic redox couple for the QDSCs is proposed.

  • 21.
    Nyström, Daniel
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Lindqvist, Josefina
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Östmark, Emma
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Antoni, Per
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Carlmark, Anna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Hult, Anders
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Malmström, Eva E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Bouncing Water Droplets on Superhydrophobic Cellulose SurfacesIn: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501Article in journal (Other academic)
  • 22.
    Salajková, Michaela
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Berglund, Lars
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Zhou, Qi
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology. KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center.
    Hydrophobic cellulose nanocrystals modified with quaternary ammonium salts2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 37, p. 19798-19805Article in journal (Refereed)
    Abstract [en]

    An environmentally friendly procedure in aqueous solution for the surface modification of cellulose nanocrystals (CNCs) using quaternary ammonium salts via adsorption is developed as inspired by organomodified layered silicates. CNCs with a high carboxylate content of 1.5 mmol g(-1) were prepared by a new route, direct hydrochloric acid hydrolysis of 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized nanofibrillated cellulose from a softwood pulp, and characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD). Four quaternary ammonium cation surfactants bearing long alkyl, phenyl, glycidyl, and diallyl groups were successfully used to modify CNCs carrying carboxylic acid groups as characterized by Fourier transform infrared spectroscopy (FTIR). The modified CNCs can be redispersed and individualized in an organic solvent such as toluene as observed by scanning transmission electron microscopy (STEM). One may envision removing excess surfactant to obtain CNC with a monolayer of surfactant. The toluene suspension of the modified CNCs showed strong birefringence under crossed polars but no further chiral- nematic ordering was observed. The model surface prepared by the CNCs modified with quaternary ammonium salts bearing C18 alkyl chains showed a significant increase in water contact angle (71 degrees) compared to that of unmodified CNCs (12 degrees). This new series of modified CNCs can be dried from solvent and have the potential to form well-dispersed nanocomposites with non-polar polymers.

  • 23. Salazar-Alvarez, German
    et al.
    Sort, Jordi
    Uheida, Abdusalam
    Muhammed, Mamoun
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering.
    Surinach, Santiago
    Dolors Baro, Maria
    Nogues, Josep
    Reversible post-synthesis tuning of the superparamagnetic blocking temperature of gamma-Fe2O3 nanoparticles by adsorption and desorption of Co(II) ions2007In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 17, no 4, p. 322-328Article in journal (Refereed)
    Abstract [en]

    The influence of the post-synthesis adsorption of Co(II) ions on the structural and magnetic properties of maghemite (gamma-Fe2O3) nanoparticles with a mean particle size of about 10 nm has been investigated. It is shown that the step-wise adsorption of Co( II) can controllably increase the blocking temperature, T-B, of the system up to 60 K with respect to that of untreated particles, while neither the particle size nor the particle size distribution are significantly modified. This is accompanied by a four-fold increase in the coercivity, H-C, at low temperatures. Using a selective leaching of the previously adsorbed Co(II) ions the T-B and H-C values of the pristine gamma-Fe2O3 nanoparticles are recovered. Hence, a reversible and controllable tailoring of the magnetic properties (e.g., T-B and H-C) of the gamma-Fe2O3 nanoparticles can be achieved by a simple adsorption and desorption process of Co( II) ions after their synthesis.

  • 24.
    Saleemi, Mohsin
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Li, Shanghua
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Johnsson, Mats
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Synthesis, processing, and thermoelectric properties of bulk nanostructured bismuth telluride (Bi(2)Te(3))2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 2, p. 725-730Article in journal (Refereed)
    Abstract [en]

    Bismuth telluride (Bi(2)Te(3)) is the best-known commercially used thermoelectric material in the bulk form for cooling and power generation applications at ambient temperature. However, its dimensionless figure-of-merit-ZT around 1 limits the large-scale industrial applications. Recent studies indicate that nanostructuring can enhance ZT while keeping the material form of bulk by employing an advanced synthetic process accompanied with novel consolidation techniques. Here, we report on bulk nanostructured (NS) undoped Bi(2)Te(3) prepared via a promising chemical synthetic route. Spark plasma sintering has been employed for compaction and sintering of Bi(2)Te(3) nanopowders, resulting in very high densification (>97%) while preserving the nanostructure. The average grain size of the final compacts was obtained as 90 +/- 5 nm as calculated from electron micrographs. Evaluation of transport properties showed enhanced Seebeck coefficient (-120 mu V K(-1)) and electrical conductivity compared to the literature state-of-the-art (30% enhanced power factor), especially in the low temperature range. An improved ZT for NS bulk undoped Bi(2)Te(3) is achieved with a peak value of similar to 1.1 at 340 K.

  • 25. Shah, F. U.
    et al.
    Glavatskih, Sergei
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Tribologi.
    Dean, P. M.
    MacFarlane, D. R.
    Forsyth, M
    Antzutkin, O. N.
    Halogen-free chelated orthoborate ionic liquids and organic ionic plastic crystals2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 14, p. 6928-6938Article in journal (Refereed)
    Abstract [en]

    Five halogen-free orthoborate salts comprised of three different cations (cholinium, pyrrolidinium and imidazolium) and two orthoborate anions, bis(mandelato) borate and bis(salicylato) borate, were synthesised and characterised by DSC, X-ray diffraction and NMR. DSC measurements revealed that glass transition points of these orthoborate salts are in the temperature range from -18 to -2 degrees C. In addition, it was found that [EMPy][BScB] and [EMIm][BScB] salts have solid-solid phase transitions below their melting points, i.e. they exhibit typical features of plastic crystals. Salts of the bis(salicylato) borate anion [BScB](-) have higher melting points compared with corresponding salts of the bis(mandelato) borate anion [BMB](-). Single crystal X-ray diffraction crystallography (for [Chol][BScB] crystals) and solid-state multinuclear (C-13, B-11 and N-15) NMR spectroscopy were employed for the structural characterisation of [Chol][BScB], [EMPy][BScB] and [EMIm][BScB], which are solids at room temperature: a strong interaction between [BScB](-) anions and [Chol](+) cations was identified as (i) hydrogen bonding between OH of [Chol](+) and carbonyl groups of [BScB](-) and (ii) as the inductive C-H center dot center dot center dot pi interaction. In the other salt, [EMIm][BScB], anions exhibit pi center dot center dot center dot pi stacking in combination with C-H center dot center dot center dot pi interactions with [EMIm]+ cations. These interactions were not identified in [EMPy] [BScB] probably because of the lack of aromaticity in cations of the latter system. Our data on the formation of a lanthanum complex with bis(salicylato) borate in the liquid mixture of La3+(aq) with [Chol][BScB] suggest that this class of novel ILs can be potentially used in the extraction processes of metal ions of rare earth elements.

  • 26. Shen, Zhijian
    et al.
    Yan, Haixue
    Grüner, Daniel
    Belova, Lyubov M.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Sakamoto, Yasuhiro
    Hu, Jianfeng
    Nan, Ce-Wen
    Hoeche, Thomas
    Reece, Michael J.
    Ferroelectric ceramics with enhanced remnant polarization by ordered coalescence of nano-crystals2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 44, p. 23547-23552Article in journal (Refereed)
    Abstract [en]

    An exceptional high ferroelectric remnant polarization (P-r) was observed in BaTiO3 ceramics owing to the formation of micron-sized grains possessing nano-scale mosaicity. Such a structural hierarchy was developed via a novel crystal-growth mechanism, namely ordered coalescence of nano-crystals achieved by synergetic atomic epitaxial growth and self-assembly of nano-crystals. The accommodating lattice defects in sub-grain boundaries due to the imperfect assembly of nano-crystals significantly contribute to the P-r enhancement by stimulating the dynamics of ferroelectric domain formation and switching. This finding defines a new approach to nanopowder sintering leading to enhanced properties sensitive to lattice defects.

  • 27.
    Ström, Valter
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Olsson, Richard T.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Rao, K. Venkat
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Engineering Material Physics.
    Real-time monitoring of the evolution of magnetism during precipitation of superparamagnetic nanoparticles for bioscience applications2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 20, p. 4168-4175Article in journal (Refereed)
    Abstract [en]

    The magnetic response as measured in real-time during aqueous co-precipitation of superparamagnetic magnetite nanoparticles is reported for the first time. An integrated AC magnetic susceptometer within the mixing zone of the reactants allows for continuous monitoring of the precipitation reaction. The methodology is illustrated by demonstrating how a rapid mixing (RM) of the reactants on the order of milliseconds yields smaller magnetic particles and a much narrower particle size distribution as compared to a slow mixing (SM) on the order of a second. The RM particles display an ultra-low coercivity Hc 8.5 A m(-1), the lowest reported value to our knowledge. The reaction is completed within one minute at room temperature, whereas a slow mix (SM) results in a slower reaction (> 1 h) and particles with ca. 4 times higher coercivity. Reaction dependences on iron ion and base concentrations are reported as well as a comparison between reactions with ammonia and sodium hydroxide. The results are explained in terms of different pH stabilities of ferrous and ferric ions within the pH range covered during the course of the reactions. It is suggested that RM is necessary to avoid uneven particle growth leading to an exaggerated particle size distribution with less than ideal magnetic properties. This in-situ magnetic measurement during the actual synthesis may become an important tool for real-time quality control. RM gives uniform batch to batch properties which is especially important for bioscience applications.

  • 28.
    Sugunan, Abhilash
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Jafri, S. Hassan M.
    Qin, Jian
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Blom, Tobias
    Toprak, Muhammet S.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Leifer, Klaus
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Low-temperature synthesis of photoconducting CdTe nanotetrapods2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 6, p. 1208-1214Article in journal (Refereed)
  • 29.
    Svagan, Anna
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Jensen, Poul
    Natl Museum Denmark.
    Dvinskikh, Sergey
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Furó, István
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Physical Chemistry.
    Berglund, Lars A.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Wallenberg Wood Science Center. KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Biocomposites.
    Towards tailored hierarchical structures in cellulose nanocomposite biofoams prepared by freezing/freeze-drying2010In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 20, no 32, p. 6646-6654Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofiber (MFC) reinforced starch-based foams, prepared by the freezing/freeze-drying route, are very interesting porous materials due to the strong MFC reinforcement of the cell wall itself. However, in order to fully realize the potential of these nanocomposite biofoams, both cell wall composition and cell structure must be controlled. The effect of starch-MFC-water suspension composition, together with preparation temperature (-27, -78, and -196 degrees C) on the foam cell structure is investigated. NMR-analysis of bound water content, DSC and freezing experiments in combination with freeze-drying experiments and FE-SEM microscopy are used to determine a suitable freeze-drying temperature. The freeze-drying temperature is critical in order to avoid cell structure collapse, as found from FE-SEM studies. By varying the cell-wall composition and preparation temperature, the foam morphology can be manipulated. The connection between cell size and starch content is considered to depend on the inherent properties of starch and a mechanism for ice crystal formation is suggested. Based on improved preparation conditions, foams with mixed open and closed cell structures and as much as 70 wt% MFC in the cell wall are created successfully.

  • 30.
    Tian, Haining
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Bora, Ilkay
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Jiang, Xiao
    Gabrielsson, Erik
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Karlsson, Karl Martin
    KTH, School of Chemical Science and Engineering (CHE), Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Hagfeldt, Anders
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry. KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD.
    Modifying organic phenoxazine dyes for efficient dye-sensitized solar cells2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 33, p. 12462-12472Article in journal (Refereed)
    Abstract [en]

    Four organic dyes bearing the phenoxazine chromophore have been synthesized and applied in dye-sensitized solar cells (DSCs). The effect of different dye structures on the performance of the DSCs was investigated systematically with photophysical, photovoltaic as well as photoelectrochemical methods. Due to the slow recombination process between injected electrons and electrolyte, the IB3 dye with two 2,4-dibutoxyphenyl units showed the best efficiency of 7.0% under 100 mW cm(-2) light illumination in the liquid state-DSCs. Moreover, the phenoxazine dyes-based solid state-DSCs were fabricated for the first time. With the IB4 dye, a higher efficiency of 3.2% has been achieved under the same light intensity.

  • 31.
    Tian, Haining
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Centres, Centre of Molecular Devices, CMD. KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Iodine-free redox couples for dye-sensitized solar cells2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 29, p. 10592-10601Article in journal (Refereed)
    Abstract [en]

    Redox couples, as one of the crucial components of dye-sensitized solar cells, have been investigated for many years. Due to the many drawbacks of I I(-)/I(3)(-) electrolyte, scientists have paid more attention to seeking other alternative electrolyte systems. Up to now, the best efficiency of iodine-free redox couple-based DSCs, 7.5%, has been achieved by ferrocene/ferrocenium redox couple under AM 1.5G, 100mW cm(-2) light illumination and other redox couples also show the promising future in DSCs. In this feature article, we systematically present three series of iodine-free redox couples including metal-complexes, inorganic and pure organic redox couples, and further compare the different photovoltaic and photophysical properties of these redox couples. As a consequence, the goals of this article are to show the important progress achieved in the redox couples research area of DSCs and analyze the advantages as well as the disadvantages of these redox couples to speed up the further development of iodine-free redox couples in the future.

  • 32. Tian, Yu-Peng
    et al.
    Li, Lin
    Zhang, Ju-Zhou
    Yang, Jia-Xiang
    Zhou, Hong-Ping
    Wu, Jie-Ying
    Sun, Ping-Ping
    Tao, Li-Min
    Guo, Ya-Hui
    Wang, Chuan-Kui
    KTH, School of Biotechnology (BIO), Theoretical Chemistry (closed 20110512).
    Xing, Hui
    Huang, Wen-Hao
    Tao, Xu-Tang
    Jiang, Min-Hua
    Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials2007In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 17, no 34, p. 3646-3654Article in journal (Refereed)
    Abstract [en]

    Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.

  • 33.
    Wahlberg, Sverker
    et al.
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Yar, Mazher Ahmed
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Abuelnaga, Mohammad Omar
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Salem, Handi G.
    Johnsson, Mats
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Material Physics, Functional Materials, FNM.
    Fabrication of Nanostructured W-Y2O3 Materials by Chemical Methods2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 25, p. 12622-12628Article in journal (Refereed)
    Abstract [en]

    A novel method for the fabrication of highly uniform oxide dispersion-strengthened (ODS) materials made by chemical processing is presented. The powders are fabricated by a two-step route starting with a chemical synthesis at room temperature, producing nanocrystalline yttrium doped tungsten trioxide hydrate precursor powders. Thermogravimetric analysis with evolved gas analysis revealed the presence of ammonium nitrate in the precursors. The second step is the reduction of the precursor in a hydrogen atmosphere at 600 and 800 degrees C. The reduced powders, containing W-1.2%Y2O3, showed two types of tungsten particles, cube-shaped with a size less than 250 nm and finer particles (<50 nm) of both spherical and cubic shape. The powder was consolidated by spark plasma sintering at 1100 degrees C, producing a bulk material with a relative density of 88%. Characterization of the sintered materials by high resolution scanning electron microscopy revealed a uniform microstructure with tungsten grains of less than 300 nm and nanosized oxide particles uniformly dispersed at the tungsten grain boundaries, as well as inside the tungsten grains. Experimental determination of the elastic properties was conducted by nanoindentation tests and fracture toughness was studied by radial indentation cracking.

  • 34. Wang, Xin
    et al.
    Ramström, Olof
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Yan, Mingdi
    KTH, School of Chemical Science and Engineering (CHE), Chemistry.
    A photochemically initiated chemistry for coupling underivatized carbohydrates to gold nanoparticles2009In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 19, no 47, p. 8944-8949Article in journal (Refereed)
    Abstract [en]

    The sensitive optoelectronic properties of metal nanoparticles make nanoparticle-based materials a powerful tool to study fundamental biorecognition processes. Here we present a new and versatile method for coupling underivatized carbohydrates to gold nanoparticles (Au NPs) via the photochemically induced reaction of perfluorophenylazide (PFPA). A one-pot procedure was developed where Au NPs were synthesized and functionalized with PFPA by a ligand-exchange reaction. Carbohydrates were subsequently immobilized on the NPs by a fast light activation. The coupling reaction was efficient, resulting in high coupling yield as well as high ligand surface coverage. A colorimetric system based on the carbohydrate-modified Au NPs was used for the sensitive detection of carbohydrate-protein interactions. Binding and cross-reactivity studies were carried out between carbohydrate-functionalized Au NPs and lectins. Results showed that the surface-bound carbohydrates not only retained their binding affinities towards the corresponding lectin, but also exhibited affinity ranking consistent with that of the free ligands in solution.

  • 35.
    Westlund, Robert
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Glimsdal, Eirik
    Department of Physics, Norwegian University of Science and Technology.
    Lindgren, Mikael
    Department of Physics, Norwegian University of Science and Technology.
    Vestberg, Robert
    Materials Research Laboratory, University of California, Santa Barbara.
    Hawker, Craig
    Materials Research Laboratory, University of California, Santa Barbara.
    Lopes, Cesar
    Department of Functional Materials, Swedish Defence Research Agency.
    Malmström, Eva E.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology.
    Click Chemistry for Photonic Applications: Triazole-Functionalized Platinum(II) Acetylides for Optical Power Limiting2008In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 18, no 2, p. 166-175Article in journal (Refereed)
    Abstract [en]

    Three different triazole-containing platinum(ii) acetylide compounds were synthesized by click chemistry and evaluated for their use in optical power limiting (OPL) applications. The triazole unit was incorporated at three different positions within, or at the end of, the conjugation path of the chromophore. The aim is to explore the possibilities of using click chemistry to prepare dendronized chromophores, and to evaluate how the triazole structure affects the photophysical properties and the optical power limiting abilities of these acetylide compounds. It is shown that the concept of click chemistry can be used to attach branched monomer units to ethynyl-phenyl arms by Huisgen 1,3-dipolar cycloaddition, forming triazole units within the chromophore. Photophysical characterization of these triazole-containing materials shows an absorption maximum within the UV-A region and emission through both fluorescence and phosphorescence. Bright phosphorescence was emitted from argon purged samples, and decay measurements thereof showed triplet lifetimes of up to 100 μs. The results from the photophysical characterization suggest that the triazole does break the conjugation path, and in order to gain maximum optical limiting the triazole needs to be placed at the end of the conjugation. All three investigated triazole-containing platinum(ii) acetylides show good optical power limiting at 532 nm (10 ns pulse, f/5 set-up, 2 mm cells). The most efficient compound, with the triazole positioned at the end of the conjugation, reaches a defined clamping level of 2.5 μJ for a sample with a concentration of 50 mM in THF and a linear transmission above 80% at 532 nm. These data can be compared to the OPL properties of Zn-based porphyrins or derivatized thiophenes, reaching clamping levels of 6-15 μJ.

  • 36.
    Yan, Mingdi
    et al.
    Department of Chemistry, Portland State University.
    Ren, J.
    Covalent immobilization of polypropylene thin films2005In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 15, no 4, p. 523-527Article in journal (Refereed)
    Abstract [en]

    This article describes a simple and versatile approach to the covalent attachment of ultrathin polypropylene films on silicon wafers. The immobilization was accomplished by way of the C-H insertion reaction of perfluorophenyl nitrenes generated by thermolysis or photolysis of perfluorophenyl azides. Covalently immobilized thin films of crystalline and amorphous polypropylene and an elastomeric copolymer of polypropylene were successfully fabricated. Patterned polypropylene films were also delineated.

  • 37. Yilmaz, E.
    et al.
    Ramström, Olof
    KTH, Superseded Departments, Chemistry.
    Moller, P.
    Sanchez, D.
    Mosbach, K.
    A facile method for preparing molecularly imprinted polymer spheres using spherical silica templates2002In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 12, no 5, p. 1577-1581Article in journal (Refereed)
    Abstract [en]

    A novel and facile preparation method for spherical molecularly imprinted polymer (MIP) beads is presented. Two types of beads were synthesized and investigated: (i) silica-MIP composites were obtained by filling spherical, porous C-4-coated silica beads with print molecule and monomers followed by polymerisation; (ii) spherical molecularly imprinted polymer beads were acquired mirroring the silica particles in size, shape and pore structure by removing the silica matrix from the silica-MIP composites. With regard to their chromatographic properties and yield of the materials both types of particle were more advantageous compared to irregularly shaped traditional MIPs. Also the work-up time to obtain imprinted spherical particles is greatly reduced compared to traditional methods using polymer monoliths, which have to be ground, sieved and sedimented. Generally, the described method may open new possibilities for synthesis of novel types of imprinted polymer formats such as membranes, bulk polymers, films or in-situ columns using appropriate support or sacrificial materials.

  • 38.
    Yin, Bo
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Hakkarainen, Minna
    KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology.
    Core-shell nanoparticle-plasticizers for design of high-performance polymeric materials with improved stiffness and toughness2011In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 21, no 24, p. 8670-8677Article in journal (Refereed)
    Abstract [en]

    Core-shell nanoparticle-plasticizers were synthesized and blended with PVC in an attempt to simultaneously improve the toughness and stiffness of the resulting materials. Halloysite, kaolin and silicon dioxide nanofillers, representing acicular, layered and spherical morphologies, were surface-grafted with poly(butylene adipate) (PBA). The surface-grafting was confirmed by FTIR and the amount of PBA grafted on the surface was determined by TGA. In the case of halloysite and silicon dioxide nanoparticles their dispersion and miscibility in the PVC matrix were remarkably improved by the surface-grafting as shown by SEM, tensile testing and DMA. The tensile stress at break for the PVC films containing 5 wt% surface-treated halloysite nanoparticles increased 15%, modulus by 65% and the strain at break was 30 times higher compared to PVC containing 5 wt% untreated halloysite nanoparticles. The PVC films containing 5 wt% surface-treated silicon dioxide nanoparticles exhibited remarkably higher strain at break values compared to plain PVC/silicon dioxide composites, but also somewhat lower stress at break values probably due to the considerably higher amount of PBA grafted on the silicon dioxide surfaces. The higher storage modulus for PVC with surface modified silicon dioxide, however, still indicates higher stiffness for the material containing surface treated nanoparticles. Altogether the results show that the nanoparticle-plasticizer concept could be applied to simultaneously improve the toughness and stiffness of the materials and further improvements could be achieved after optimization of the number of PBA chains and their molecular weight.

  • 39.
    Yuan, Chunze
    et al.
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Chen, Guanying
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Prasad, Paras N.
    Ohulchanskyy, Tymish Y.
    Ning, Zhijun
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Tian, Haining
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Sun, Licheng
    KTH, School of Chemical Science and Engineering (CHE), Chemistry, Organic Chemistry.
    Ågren, Hans
    KTH, School of Biotechnology (BIO), Theoretical Chemistry and Biology.
    Use of colloidal upconversion nanocrystals for energy relay solar cell light harvesting in the near-infrared region2012In: Journal of Materials Chemistry, ISSN 0959-9428, E-ISSN 1364-5501, Vol. 22, no 33, p. 16709-16713Article in journal (Refereed)
    Abstract [en]

    Colloidal upconversion (UC) nanocrystals were explored as energy relay materials for dye-sensitized solar cells for the first time. The utilization of colloidal UC nanocrystals was found to significantly enhance the upconversion efficiency and improve the photocurrent of the cells for low infrared irradiation intensity. In addition, it was found that UC nanocrystals of small size favor infiltration into a TiO2 film and bring higher relay efficiency. Finally, we found that UC nanocrystals can serve as a scattering material to increase the light absorption capability of the cells and increase the overall photocurrent of the cells under simulated sunlight irradiation.

1 - 39 of 39
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf