123. High tensile strength and high ionic conductivity bionanocomposite ionogels prepared by gelation of cellulose/ionic liquid solutions with nano-silica
writer：Hongzan Song, Zhiqiang Luo, Hongchi Zhao, Shanshan Luo, Xiaojing Wu, Jungang Gao and Zhigang Wang
keywords：纖維素，離子液體，納米SiO2，凝膠
source：期刊
specific source：RSC Advances, 2013, 3, 11665-11675
Issue time：2013年
本文報道成功制備了由1-乙基-3-甲基咪唑醋酸離子液體、微晶纖維素和納米二氧化硅粒子組成的具有高強度和高離子導電率的新型生物納米復合離子凝膠。動態光散射（DLS）和透射電鏡（TEM）結果表明納米二氧化硅粒子在離子凝膠中能夠很好分散。為了闡明納米二氧化硅粒子對體系在溶液-凝膠轉變和液晶相轉變的影響，采用動態流變學測試、力學性能測試和偏光顯微鏡對體系進行研究。流變學測試結果表明納米二氧化硅粒子加入可以誘導并加快凝膠化過程。體系溶液-凝膠的相轉變溫度和彈性模量可以通過改變微晶纖維素和納米二氧化硅粒子的含量來調節，其值可以分別達到125°C和7 × 105 Pa。偏光顯微鏡觀察結果表明，納米二氧化硅粒子加入明顯抑制了離子凝膠的液晶行為。更為重要的是，發現在30 °C時離子凝膠的離子電導率可以達到10−3 S cm−1數量級，并且離子凝膠的離子電導率隨其溫度增加和微晶纖維素濃度減小而增大。上述結果表明，這類具有高強度拉伸性能的新型離子凝膠有望作為凝膠聚合物電解質而得到應用。
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.