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Study of Structure-Function Relationships of Zwitterionic Polymers
Başlık:
Study of Structure-Function Relationships of Zwitterionic Polymers
Yazar:
Lee, Chen-Jung, author.
ISBN:
9780438096929
Yazar Ek Girişi:
Fiziksel Tanımlama:
1 electronic resource (139 pages)
Genel Not:
Source: Dissertation Abstracts International, Volume: 79-10(E), Section: B.
Advisors: Hongbo Cong Committee members: Gang Cheng; Xiong Gong; Lingyun Liu; Yang Liu; Jie Zheng.
Özet:
This dissertation is to study the structure-property relationships of zwitterionic materials from the aspect of molecular level with integrating its antifouling ability into other functions including buffering ability, ionic conductivity and electronic conductivity.
In the first project (chapter II), a tertiary amine-based polycarboxybetaine (PCB) were synthesized to compare with the conventional quaternary ammonium-based PCB in order to study how tertiary amine group affect the properties of the resulting polymer. Replacing quaternary ammonium with tertiary amine not only endowed this tertiary aminebased PCB with buffering capability at neutral condition, but also led to a weaker carboxylate that leads a less acidic buffering range. It was found that tertiary amine is favorable to obtain good lactone ring stability in switchable PCB materials. More importantly, the tertiary amine cation does not compromise antifouling properties of zwitterionic materials.
In the second project (chapter III), three typical but structurally different zwitterionic materials, polycarboxybetaine, polysulfobetaine, and polyphosphorylcholine, were studied on their ionic conductivity along with other materials. Recently, zwitterions have shown its potential on enhancement of the ionic dissociation. To gain a better understanding on how immobilized zwitterionic functional group interact with the mobile ions in the solution, a series of polyelectrolyte hydrogels, including zwitterionic, cationic, anionic hydrogels, were examined and compared on their ionic conductivity and volume change in three types of salt solutions with various concentration. Zwitterionic hydrogels showed much higher ionic conductivity than that of the nonionic poly(ethylene glycol) methyl ether methacrylate hydrogel in all tested solutions. For both cationic and anionic hydrogels, the presence of mobile counterions led to high ionic conductivity in low salt solutions; however, the ionic conductivity of zwitterionic hydrogels surpassed that of cationic and ionic hydrogels in high salt solutions.
In the third and fourth projects (chapter IV and V), zwitterionic sulfobetaine functional group was incorporated with poly(ethylenedioxythiophene) (PEDOT) to create a series of zwitterionic conjugated polymers, and the effect of sulfobetaine group on the conjugated polymer chain was studied. To address the challenge of the long-term stability in implantable bioelectronics, zwitterionic material with superior antifouling and conducting ability is highly desired for the interface between biological system and electronic system. Therefore, Poly(sulfobetaine-3,4-ethylenedioxythiophene) (PSBEDOT) was designed to combine the advantages of zwitterionic material and conjugated material. The PSBEDOT-coated surface exhibited low interfacial impedance, good cyclic stability and switchable antifouling/antimicrobial properties. In addition, two PSBEDOT derivatives with different spacer length, PSBEDOT-4 and PSBEDOT-5, were synthesized to compare with PSBEDOT to study how the zwitterionic sulfobetaine side group affects the reactivity of monomer and the properties of the resulting polymer. It was found that PSBEDOT-4 and PSBEDOT-5 showed significant improvement on interfacial impedance and cyclic stability without compromising antifouling properties.
Notlar:
School code: 0003
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Yer Numarası | Demirbaş Numarası | Shelf Location | Lokasyon / Statüsü / İade Tarihi |
---|---|---|---|
XX(687168.1) | 687168-1001 | Proquest E-Tez Koleksiyonu | Arıyor... |
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