123. High tensile strength and high ionic conductivity bionanocomposite ionogels prepared by gelation of cellulose/ionic liquid solutions with nano-silica
作者：Hongzan Song, Zhiqiang Luo, Hongchi Zhao, Shanshan Luo, Xiaojing Wu, Jungang Gao and Zhigang Wang
关键字：纤维素，离子液体，纳米SiO2，凝胶
论文来源：期刊
具体来源：RSC Advances, 2013, 3, 11665-11675
发表时间：2013年
本文报道成功制备了由1-乙基-3-甲基咪唑醋酸离子液体、微晶纤维素和纳米二氧化硅粒子组成的具有高强度和高离子导电率的新型生物纳米复合离子凝胶。动态光散射（DLS）和透射电镜（TEM）结果表明纳米二氧化硅粒子在离子凝胶中能够很好分散。为了阐明纳米二氧化硅粒子对体系在溶液-凝胶转变和液晶相转变的影响，采用动态流变学测试、力学性能测试和偏光显微镜对体系进行研究。流变学测试结果表明纳米二氧化硅粒子加入可以诱导并加快凝胶化过程。体系溶液-凝胶的相转变温度和弹性模量可以通过改变微晶纤维素和纳米二氧化硅粒子的含量来调节，其值可以分别达到125°C和7 × 105 Pa。偏光显微镜观察结果表明，纳米二氧化硅粒子加入明显抑制了离子凝胶的液晶行为。更为重要的是，发现在30 °C时离子凝胶的离子电导率可以达到10−3 S cm−1数量级，并且离子凝胶的离子电导率随其温度增加和微晶纤维素浓度减小而增大。上述结果表明，这类具有高强度拉伸性能的新型离子凝胶有望作为凝胶聚合物电解质而得到应用。
Novel bionanocomposite ionogels consisting of an ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate (EMIMAc), microcrystalline cellulose (MCC) and nano-silica (nano-SiO2) particles with high tensile strength and high ionic conductivity have been successfully prepared. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) measurements reveal a homogeneous dispersion of nano-SiO2 in the MCC/nano-SiO2/EMIMAc bionanocomposite ionogels. In order to clarify the influences of added nano-SiO2 on the sol–gel transition process and liquid crystalline phase transition for the MCC/nano-SiO2/EMIMAc systems, the complexes were investigated by dynamic rheological measurements, mechanical tensile property tests and polarized optical microscope (POM) observations. The rheological results indicate that the introduction of nano-SiO2 can induce and accelerate the gelation for the MCC/nano-SiO2/EMIMAc solutions. By adjusting the MCC and nano-SiO2 concentrations, the gel-sol transition temperature and elastic modulus can be well controlled and the optimized values reach 125 °C and 7 × 105 Pa, respectively. The POM results reveal that the addition of nano-SiO2 significantly suppresses the liquid crystalline behavior of ionogels. A more significant result is that the bionanocomposite ionogels exhibit high ionic conductivity in the order of 10−3 S cm−1 at 30 °C. The ionic conductivity of the ionogels increases with increasing temperature and decreasing MCC concentration. The above results demonstrate that the novel bionanocomposite ionogels with high tensile strength are promising for the application as gel polymer electrolytes (GPE) in electrochemical devices.