Change search
Link to record
Permanent link

Direct link
BETA
Kaldéus, Tahani
Publications (10 of 12) Show all publications
Kaldéus, T., Telaretti Leggieri, M. R., Cobo Sanchez, C. & Malmström, E. (2019). All-aqueous SI-ARGET ATRP from cellulose nanofibrils using hydrophilic and hydrophobic monomers.
Open this publication in new window or tab >>All-aqueous SI-ARGET ATRP from cellulose nanofibrils using hydrophilic and hydrophobic monomers
2019 (English)In: Article in journal (Other academic) Submitted
National Category
Polymer Technologies Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-244057 (URN)
Note

QC 201902

Available from: 2019-02-15 Created: 2019-02-15 Last updated: 2019-02-18Bibliographically approved
Kaldéus, T., Leggieri, M. R., Sanchez, C. & Malmström, E. (2019). All-Aqueous SI-ARGET ATRP from Cellulose Nanofibrils Using Hydrophilic and Hydrophobic Monomers. Biomacromolecules, 20(5), 1937-1943
Open this publication in new window or tab >>All-Aqueous SI-ARGET ATRP from Cellulose Nanofibrils Using Hydrophilic and Hydrophobic Monomers
2019 (English)In: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 20, no 5, p. 1937-1943Article in journal (Refereed) Published
Abstract [en]

An all-water-based procedure for "controlled" polymer grafting from cellulose nanofibrils is reported. Polymers and copolymers of poly(ethylene glycol) methyl ether methacrylate (POEGMA) and poly(methyl methacrylate) (PMMA) were synthesized by surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (SI-ARGET ATRP) from the cellulose nanofibril (CNF) surface in water. A macroinitiator was electrostatically immobilized to the CNF surface, and its amphiphilic nature enabled polymerizations of both hydrophobic and hydrophilic monomers in water. The electrostatic interactions between the macroinitiator and the CNF surface were studied by quartz crystal microbalance with dissipation energy (QCM-D) and showed the formation of a rigid adsorbed layer, which did not desorb upon washing, corroborating the anticipated electrostatic interactions. Polymerizations were conducted from dispersed modified CNFs as well as from preformed modified CNF aerogels soaked in water. The polymerizations yielded matrix-free composite materials with a CNF content of approximately 1-2 and 3-6 wt % for dispersion-initiated and aerogel-initiated CNFs, respectively.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-252629 (URN)10.1021/acs.biomac.9b00153 (DOI)000468120800010 ()30889349 (PubMedID)2-s2.0-85064116173 (Scopus ID)
Note

QC 20190603

Available from: 2019-06-03 Created: 2019-06-03 Last updated: 2019-06-03Bibliographically approved
Kaldéus, T., Träger, A., Berglund, L., Malmström, E. & Lo Re, G. (2019). Molecular engineering of cellulose-PCL bio-nanocomposite interface by reactive amphiphilic copolymer nanoparticles.
Open this publication in new window or tab >>Molecular engineering of cellulose-PCL bio-nanocomposite interface by reactive amphiphilic copolymer nanoparticles
Show others...
2019 (English)In: Article in journal (Refereed) Accepted
National Category
Polymer Technologies Paper, Pulp and Fiber Technology Composite Science and Engineering
Identifiers
urn:nbn:se:kth:diva-244058 (URN)
Note

QC 20190218

Available from: 2019-02-15 Created: 2019-02-15 Last updated: 2019-02-18Bibliographically approved
Kaldéus, T., Träger, A., Berglund, L., Malmström, E. & Lo Re, G. (2019). Molecular Engineering of the Cellulose-Poly(Caprolactone) Bio-Nanocomposite Interface by Reactive Amphiphilic Copolymer Nanoparticles. ACS NANO, 13(6), 6409-6420
Open this publication in new window or tab >>Molecular Engineering of the Cellulose-Poly(Caprolactone) Bio-Nanocomposite Interface by Reactive Amphiphilic Copolymer Nanoparticles
Show others...
2019 (English)In: ACS NANO, Vol. 13, no 6, p. 6409-6420Article in journal (Refereed) Published
Abstract [en]

A molecularly engineered water-borne reactive compatibilizer is designed for tuning of the interface in melt-processed thermoplastic poly(caprolactone) (PCL)-cellulose nanocomposites. The mechanical properties of the nanocomposites are studied by tensile testing and dynamic mechanical analysis. The reactive compatibilizer is a statistical copolymer of 2-(dimethylamino)ethyl methacrylate and 2-hydroxy methacrylate, which is subsequently esterified and quaternized. Quaternized ammonium groups in the reactive compatibilizer electrostatically match the negative surface charge of cellulose nanofibrils (CNFs). This results in core-shell CNFs with a thin uniform coating of the compatibilizer. This promotes the dispersion of CNFs in the PCL matrix, as concluded from high-resolution scanning electron microscopy and atomic force microscopy. Moreover, the compatibilizer "shell" has methacrylate functionalities, which allow for radical reactions during processing and links covalently with PCL. Compared to the bio-nanocomposite reference, the reactive compatibilizer (<4 wt %) increased Young's modulus by about 80% and work to fracture 10 times. Doubling the amount of peroxide caused further improved mechanical properties, in support of effects from higher cross-link density at the interface. Further studies of interfacial design in specific nanocellulose-based composite materials are warranted since the detrimental effects from CNFs agglomeration may have been underestimated.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
Keywords
biocomposite, nanocellulose, reactive processing, mechanical properties, interphase, interface, biodegradable
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-255446 (URN)10.1021/acsnano.8b08257 (DOI)000473248300027 ()31083978 (PubMedID)2-s2.0-85066407552 (Scopus ID)
Note

QC 20190820

Available from: 2019-08-20 Created: 2019-08-20 Last updated: 2019-08-20Bibliographically approved
Kaldéus, T., Nordenström, M., Erlandsson, J., Wågberg, L. & Malmström, E. (2019). Redispersibility properties of dried cellulose nanofibrils - influence on structure and mechanical properties.
Open this publication in new window or tab >>Redispersibility properties of dried cellulose nanofibrils - influence on structure and mechanical properties
Show others...
2019 (English)In: Article in journal (Other academic) Epub ahead of print
National Category
Polymer Technologies Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-244055 (URN)
Note

QC 20190218

Available from: 2019-02-15 Created: 2019-02-15 Last updated: 2019-02-18Bibliographically approved
Kaldéus, T. (2019). Surface modification approaches of cellulose nanofibrils and their effect on dispersibility. (Doctoral dissertation). Stockholm: KTH Royal Institute of Technology
Open this publication in new window or tab >>Surface modification approaches of cellulose nanofibrils and their effect on dispersibility
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

In the strive to find and develop sustainable bio-based materials an increased interest for nanocellulosic materials as attractive alternatives has arisen during the past decades. This can be attributed to their abundant renewability, remarkable inherent mechanical properties and their capability to be chemically modified. Cellulose nanofibrils (CNFs) are commonly obtained from wood pulp fibres and prepared through mechanical, chemical and/or enzymatic treatments. However, due to their hydrophilic nature and tendency to self-aggregate, their surface chemistry need to be altered to fully utilise their inherent properties and enable their usage in conventional large-scale industrial processes.

This thesis work focuses on elucidating the fundamental aspects of the colloidal stability of highly concentrated CNF dispersions and the redispersibility of dried CNFs. Small amounts of amine-terminated poly(ethylene glycol) (PEG) were used to sterically stabilise the CNFs at higher fibril concentrations and delay the dispersion-arrested state transition (Paper I). The redispersibility of dried CNFs was studied for differently charged CNFs as a function of redispersing agents such as carboxymethyl cellulose (CMC), PEG and lignin (Paper II).

This thesis presents green, facile modification approaches as well as strategies for improved dispersibility and compatibility with polymer matrices. The commercially established carboxymethylation process was expanded with a subsequent functionality step, yielding a mild, versatile one-pot protocol for the preparation of bi-functional CNFs (Paper III). Further, reactive amphiphilic macromolecules with targeted side-chain functionalities were used to compatibilise the CNF surface by water-based approaches. In the first study, a macroinitiator was used for the development of a versatile, yet facile, protocol for the controlled polymerisation of both hydrophilic and hydrophobic monomers in water from the CNF surface (Paper IV). In the second study, a reactive macro-compatibiliser was used to molecularly engineer the interface between CNFs and a polymer matrix by reactive-melt processing, yielding nanocomposites with improved stiffness while maintaining the deformability (Paper V).

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2019. p. 60
Series
TRITA-CBH-FOU ; 2019:12
Keywords
cellulose nanofibrils, colloidal stability, re/dispersibility, surface modification, bio-nanocomposites, interface, cellulosa nanofibriller, kolloidal stabilitet, re/dispergerbarhet, ytmodifiering, bio-nanokompositer, gränssnitt
National Category
Polymer Technologies Paper, Pulp and Fiber Technology
Research subject
Fibre and Polymer Science
Identifiers
urn:nbn:se:kth:diva-244070 (URN)978-91-7873-093-3 (ISBN)
Public defence
2019-03-22, F3, Lindstedtsvägen 26, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20190221

Available from: 2019-02-22 Created: 2019-02-17 Last updated: 2019-02-25Bibliographically approved
Kaldéus, T., Nordenström, M., Carlmark, A., Wågberg, L. & Malmström, E. (2018). Insights into the EDC-mediated PEGylation of cellulose nanofibrils and their colloidal stability. Carbohydrate Polymers, 181, 871-878
Open this publication in new window or tab >>Insights into the EDC-mediated PEGylation of cellulose nanofibrils and their colloidal stability
Show others...
2018 (English)In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 181, p. 871-878Article in journal (Refereed) Published
Abstract [en]

EDC-mediated coupling has frequently been utilized to poly(ethylene glycol) functionalize (PEGylate) cellulose-based materials, but no work has previously been reported on the direct N-(3-dimethylaminopropyl)-N-ethylcarbodiimide (EDC)-mediated PEGylation of cellulose nanofibrils (CNF). Herein, we report the first study where CNF has been directly sterically stabilized with amine-terminated PEG employing N-hydroxysuccinimide (NHS)-assisted EDC-coupling. This work has shown that this coupling reaction is highly sensitive to the reaction conditions and purification procedures, and hence an optimized coupling protocol was developed in order to achieve a reaction yield. Elemental analysis of the nitrogen content also showed the successful PEGylation. It was also shown that a surprisingly low PEGylation (1%) is sufficient to significantly improve the colloidal stability of the PEGylated samples, which reached dispersion-arrested-state-transitions at higher concentrations than neat CNF. The colloidal stability was preserved with increasing ionic strength, when comparably long polymer chains were grafted, targeting only 1% PEGylation.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Cellulose nanofibrils, Colloidal stability, PEGylation, Steric stabilization
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-220410 (URN)10.1016/j.carbpol.2017.11.065 (DOI)000418661000101 ()29254048 (PubMedID)2-s2.0-85037689178 (Scopus ID)
Note

QC 20171220

Available from: 2017-12-20 Created: 2017-12-20 Last updated: 2019-02-17Bibliographically approved
Kaldéus, T., Larsson, P. T., Boujemaoui, A. & Malmström, E. (2018). One-pot preparation of bi-functional cellulose nanofibrils. Cellulose (London), 25(12), 7031-7042
Open this publication in new window or tab >>One-pot preparation of bi-functional cellulose nanofibrils
2018 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 25, no 12, p. 7031-7042Article in journal (Refereed) Published
Abstract [en]

Herein, we present a route to obtain bi-functional cellulose nanofibrils (CNF) by a one-pot approach using an already established functionalisation route, carboxymethylation, to which a subsequent functionalisation step, allylation or alkynation, has been added in the same reaction pot, eliminating the need of solvent exchange procedures. The total charge of the fibres and the total surface charge of the nanofibrils were determined by conductometric and polyelectrolyte titration, respectively. Furthermore, the allyl and alkyne functionalised cellulose were reacted with methyl 3-mercaptopropionate and azide-functionalised disperse red, respectively, to estimate the degree of functionalisation. The samples were further assessed by XPS and FT-IR. Physical characteristics were evaluated by CP/MAS C-13-NMR, XRD, AFM and DLS. This new approach of obtaining bi-functionalised CNF allows for a facile and rapid functionalisation of CNF where chemical handles can easily be attached and used for further modification of the fibrils.

Place, publisher, year, edition, pages
SPRINGER, 2018
Keywords
Carboxymethylation, Functionalised cellulose nanofibrils, Allylation, Alkynation
National Category
Paper, Pulp and Fiber Technology
Identifiers
urn:nbn:se:kth:diva-239754 (URN)10.1007/s10570-018-2066-y (DOI)000449946300016 ()2-s2.0-85054565647 (Scopus ID)
Note

QC 20190110

Available from: 2019-01-10 Created: 2019-01-10 Last updated: 2019-02-17Bibliographically approved
Mittal, N., Kaldéus, T., Lundell, F. & Söderberg, D. (2017). Effect of cellulose nanofibril morphology on the strength and stiffness of macroscopic filaments. Paper presented at 253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, APR 02-06, 2017, San Francisco, CA. Abstract of Papers of the American Chemical Society, 253
Open this publication in new window or tab >>Effect of cellulose nanofibril morphology on the strength and stiffness of macroscopic filaments
2017 (English)In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 253Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
American Chemical Society (ACS), 2017
National Category
Chemical Sciences
Identifiers
urn:nbn:se:kth:diva-243613 (URN)000430568503387 ()
Conference
253rd National Meeting of the American-Chemical-Society (ACS) on Advanced Materials, Technologies, Systems, and Processes, APR 02-06, 2017, San Francisco, CA
Note

QC 20190205

Available from: 2019-02-05 Created: 2019-02-05 Last updated: 2019-02-05Bibliographically approved
Kaldéus, T., Carlmark, A. & Malmström, E. (2016). Controlling colloidal stability in nanofibrillar systems by surface modification. Abstracts of Papers of the American Chemical Society, 251
Open this publication in new window or tab >>Controlling colloidal stability in nanofibrillar systems by surface modification
2016 (English)In: Abstracts of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 251Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2016
National Category
Organic Chemistry
Identifiers
urn:nbn:se:kth:diva-242688 (URN)000431903802437 ()
Note

QC 20190221

Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-08-21Bibliographically approved
Organisations

Search in DiVA

Show all publications