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Chemical Pathways to Electrically Conductive Hemicellulose Hydrogels
KTH, School of Chemical Science and Engineering (CHE), Fibre and Polymer Technology, Polymer Technology. Sichuan University.ORCID iD: 0000-0003-2689-0251
2014 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Hydrogels have been extensively explored and are widely used in diverse biomedical applications, such as scaffolds for tissue engineering and vehicles for drug delivery. As one type of important natural polymer-based hydrogel, hemicellulose hydrogels have interesting attributes, including being renewable, non-toxic, biocompatible, biodegradable, and abundantly available. A prominent way to extend their potential is by combining them with desirable properties from other materials. The focus of this thesis is to develop a new family of electrically conductive hemicellulose-based hydrogels (ECHHs) using O-acetyl-galactoglucomannan (AcGGM) and aniline oligomers through different chemical pathways.

A first approach to synthesize the ECHHs includes two steps: first, carboxylated AcGGM (C-AcGGM) is dissolved with glycidyl methacrylate, followed by polymerization initiated by ammonium persulfate; second, the resulting hydrogels are covalently coupled to varying amounts of aniline tetramer (AT), which is homogeneously distributed throughout the network. The swelling ratios of C-AcGGM hydrogels decrease as the degree of substitution of maleic anhydride increases. The swelling ratios and conductivities of ECHHs are tuned by the AT content.

To develop a simpler and greener approach to synthesize ECHHs under ambient conditions, AcGGM is in-situ cross-linked in the presence of aniline pentamer (AP) in basic water. Hydrogel equilibrium swelling ratios (ESRs) vary from 12.7 to 10.4, regulated by cross-linker concentration. The ESRs are also tuned from 9.6 to 6.0 by changing the AP contents from 10 % (w/w) to 40 % (w/w) while simultaneously altering conductivities from 9.05×10-9 to 1.58×10-6 S/cm.

ECHHs with controllable conductivity, tunable swelling behavior and acceptable mechanical properties extend the applications of hemicellulose to include e.g. biosensors and electronic devices.

Abstract [sv]

Hydrogeler har varit föremål för omfattande forskning och funnit bred användning i en rad olika biomedicinska applikationer, så som stöd för vävnadsregenerering eller som matriser för läkemedelsfrisättning. Hydrogeler av hemicellulosa representerar en viktig klass av hydrogeler – baserade på naturliga polymerer – och har många intressanta egenskaper, så som förnybarhet, icke-toxicitet, biokompatibilitet, och nedbrytbarhet. Ett attraktivt sätt att utöka dessa hydrogelers potential är att kombinera dem med eftertraktade egenskaper som andra material besitter. Avhandlingsarbetets fokus har varit att utveckla en ny familj elektriskt ledande hemicellulosa-baserade hydrogeler (ECHHs) från O-acetyl-galaktoglukomannan (AcGGM) och oligomerer av aniline via olika syntesvägar.

En nyutvecklad syntesmetod för att skapa ECHHs utgörs av en tvåstegsprocess: i ett första steg blandas karboxylerad AcGGM (C-AcGGM) med glycidylmetakrylat och sampolymeriseras efter initiering med ammoniumpersulfat. I nästa steg kopplas de bildade hydrogelerna kovalent till anilinetetramerer (AT) i olika halter som dispergerats homogent i nätverket. Svällningskapaciteten hos hydrogelerna minskar då substitutionsgraden av maleinsyraanhydrid hos C-AcGGM ökar. Vidare kan såväl svällningsgrad som konduktivitet hos ECHHs justeras genom att ändra halten AT i nätverket.

En enklare och grönare syntesväg utvecklades sedan för att skapa ECHHS genom att tvärbinda AcGGM i närvaro av anilinpentamerer (AP) i en enstegsprocess vid rumstemperatur och i basisk vattenlösning. Vid jämvikt når svällningsgraden (ESRs) hos hydrogelerna värden mellan 12.7 och 10.4 beroende på koncentrationen av tvärbindning. ESRs ändras från 9.6 till 6.0 då halten AP ökar från 10 till 40 viktsprocent samtidigt som konduktiviteten ökar från 9.05×10-9 to 1.58×10-6 S/cm.

ECHHs med kontrollerbar elektrisk ledningsförmåga, justerbar svällningskapacitet och adekvata mekaniska egenskaper möjliggör nya användningsområden för hemicellulosa, till exempel som biosensorer

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2014. , 50 p.
Series
TRITA-CHE-Report, ISSN 1654-1081 ; 2014:24
Keyword [en]
Electrically conductive, hemicellulose, hydrogels, swelling behavior, aniline oligomers, renewable, polymer synthesis
Keyword [sv]
Elektriskt ledande, hemicellulosa, hydrogel, svällning, anilinoligomerer, förnyelsebar, polymersyntes
National Category
Polymer Chemistry
Research subject
Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-146858ISBN: 978-91-7595-183-6 (print)OAI: oai:DiVA.org:kth-146858DiVA: diva2:725924
Presentation
2014-08-22, K2, Teknikringen 28, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20140617

Available from: 2014-06-17 Created: 2014-06-17 Last updated: 2014-06-17Bibliographically approved
List of papers
1. A robust pathway to electrically conductive hemicellulose hydrogels with high and controllable swelling behavior
Open this publication in new window or tab >>A robust pathway to electrically conductive hemicellulose hydrogels with high and controllable swelling behavior
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2014 (English)In: Polymer, ISSN 0032-3861, E-ISSN 1873-2291, Vol. 55, no 13, 2967-2976 p.Article in journal (Refereed) Published
Abstract [en]

A robust pathway to synthesize electrically conductive hemicellulose hydrogels (ECHHs) based on O-acetylgalactoglucomannan (AcGGM) and conductive aniline tetramer (AT) is presented. These ECHHs were obtained by functionalizing carboxylated AcGGM with glycidyl methacrylate (GMA) and subsequently covalently immobilizing AT onto GMA. Hydrogel swelling ratios (SRs) were regulated by the degree of substitution (DS) of the carboxylated AcGGM, the maximum varied as follows: SRDS=1.14 < SRDS=0.60 < SRDS=0.24. The SR can also be tuned from 548% to 228% by changing the AT contents from 10% (w/w) to 40% (w/w) while simultaneously altering conductivities from 2.93 x 10(-8) to 1.12 x 10(-6) S/cm. Free-standing ECHHs with tunable conductivity and degree of swelling, as presented herein, have a broad potential for biomedical applications.

Keyword
Hydrogels, Hemicellulose, Electrically conductive
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-146864 (URN)10.1016/j.polymer.2014.05.003 (DOI)000337549000005 ()2-s2.0-84902104788 (Scopus ID)
Funder
EU, European Research Council, 246776
Note

QC 20140617

Available from: 2014-06-17 Created: 2014-06-17 Last updated: 2017-12-05Bibliographically approved
2. Facile and Green Approach towards Electrically Conductive Hemicellulose Hydrogels with Tunable Conductivity and Swelling Behavior
Open this publication in new window or tab >>Facile and Green Approach towards Electrically Conductive Hemicellulose Hydrogels with Tunable Conductivity and Swelling Behavior
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2014 (English)In: Chemistry of Materials, ISSN 0897-4756, E-ISSN 1520-5002, Vol. 26, no 14, 4265-4273 p.Article in journal (Refereed) Published
Abstract [en]

A one-pot reaction to synthesize electrically conductive hemicellulose hydrogels (ECHHs) is developed via a facile and green approach in water and at ambient temperature. ECHHs were achieved by cross-linking O-acetyl-galactoglucomannan (AcGGM) with epichlorohydrin in the presence of conductive aniline pentamer (AP) and were confirmed by infrared spectroscopy (IR) and elemental analysis. All hydrogels had macro-porous structures, and the thermal stability of ECHHs was improved by the addition of AP. Hydrogel equilibrium swelling ratios (ESRs) varied from 13.7 to 11.4 and were regulated by cross-linker concentration. The ESRs can also be tuned from 9.6 to 6.0 by changing the AP content level from 10 to 40% (w/w) while simultaneously altering conductivity from 9.05 x 10(-9) to 1.58 X 10(-6) S/cm. ECHHs with controllable conductivity, tunable swelling behavior, and acceptable mechanical properties have great potential for biomedical applications, such as biosensors, electronic devices, and tissue engineering.

Keyword
Biomedical Applications, Polysaccharide Hydrogels, In-Vitro, Thermoresponsive Hydrogels, Thermosensitive Hydrogels, Composite Hydrogels, Aniline Pentamer, Cross-Linking, Polymer, Epichlorohydrin
National Category
Polymer Chemistry
Identifiers
urn:nbn:se:kth:diva-146867 (URN)10.1021/cm501852w (DOI)000339471400030 ()2-s2.0-84904670901 (Scopus ID)
Funder
EU, European Research Council
Note

QC 20140822. Updated from manuscript to article in journal.

Available from: 2014-06-17 Created: 2014-06-17 Last updated: 2017-12-05Bibliographically approved

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