摘要
以聚乙烯醇/硼酸盐(PB)凝胶体系作为导电水凝胶(ECHs)基本骨架,在纤维素纳米纤丝(cellulose nanofibers,CNFs)上原位聚合吡咯单体(Py)得到CNF-PPy复合物,再将其分散到PB基体当中,制得高可塑性和一定自修复特性的纳米复合导电水凝胶(PB-CNF-PPy)。对胶体化学官能团、微观形貌、晶型结构、流变特性和导电性等性能的测试分析发现:原位聚合过程保持了PPy的共轭结构及其导电性,胶体表面呈蜂窝多孔状,孔隙直径为(4.62±0.05)μm。凝胶平均含水率和密度分别为90.61%和1.13 g/cm3;随着CNF和PPy含量的提高,胶体黏弹性、力学强度和导电性都明显增强。当CNF为2.0%、PPy为0.5%时,存储模量G'可达5.5 k Pa,约为纯PB凝胶的70倍,能承受的最大应力约为CNF 1.0%、PPy 0.5%时的8~9倍,电导率可达3.38×10-2S/m。
The PVA/borate（PB）hydrogel was used as the basic skeleton of electro-conductive hydrogels（ECHs）. Firstly, the cellulose nanofibers-polypyrrole（CNF-PPy）complex was obtained by in-situ polymerization of the pyrrole monomer in cellulose nanofibers（CNFs）. Then it was dispersed into the PB matrix. A double layer network structure, namely a CNF enhanced network and a PPy conductive network, was constructed in the colloid. A composite conductive hydrogel with high plasticity and self-repairing properties was successfully prepared. The functional groups, micro morphology, crystal structure, rheological properties and electrical conductivity of the hydrogel were characterized. The results showed that the polymerization of PPy and CNF maintained the conjugate structure of PPy and thus its conductivity. The hydrogel microstructure presented a honeycomb-like porous structure, and the void diameter was about（4.62±0.05）μm. The average water content of the hydrogel was 90.61% and the average density was 1.13 g/cm^3. With the increase of CNF and PPy content, the viscoelasticity and mechanical strength of the hydrogel were significantly enhanced. When the mass ratio of CNF was 2.0% and PPy was 0.5%, the storage modulus G＇ was up to 5.5 kPa which was about 70 times of the pure PB. The maximum stress that it could bear was 8-9 times higher than that of the hydrogel with 1.0% CNF and 0.5% PPy. The electrical conductivity reached up to 3.38×10^-2 S/m. The ECHs not only has the unique physical and mechanical properties, but also has the electrical properties of conductive polymers. Therefore, the as-prepared ECHs are expected to be applied in the field of conductive films and electrical sensors.
出处
《林业工程学报》
北大核心
2017年第1期84-89,共6页
Journal of Forestry Engineering
基金
国家自然科学基金(31400505)
江苏省自然科学基金(BK20140975)
江苏省高校自然科学研究面上项目(14KJB220004)
2016年度江苏省第五期"333高层次人才培养工程"资助
2016年度江苏省高校"青蓝工程"资助
关键词
纤维素纳米纤丝
聚乙烯醇
聚吡咯
导电水凝胶
原位聚合
cellulose nanofibers
polyvinyl alcohol
polypyrrole
electroconductive hydrogel
in-situ polymerization
