SiO2@PEGMA composites were synthesized by grafting poly(ethylene glycol) methacrylate (PEGMA) on SiO2 nanoparticles via radical polymerization. The chemical structures of the SiO2@PEGMA composites were analyzed by Fourier transform infrared, 1H NMR, and transmission electron microscopy methods. The mechanical and fresh properties, hydration products, heat of hydration, microtopography, and pore structures were studied. The shell formed by the grafted PEGMA gave the SiO2@PEGMA composite a steric hindrance effect, which enabled it to have excellent dispersion stability even in the cement pore solution. The SiO2@PEGMA composites could not only effectively facilitate hydration reaction and generate calcium silicate hydrate (C–S–H) through the seeding effect but also make the pore structure more compact by the filling effect. Compared with other control groups, SiO2@PEGMA composites could obviously enhance the compressive strength of cement samples, which was increased by 36.7% after curing for 28 days.
Shi Wang,Hao Xu,Ailian Wang,Xu Liu,Jie Chen,Zhinan Wang,Di Feng,Qinghui Zeng,Liaoyun Zhang
An inorganic-polymeric hybrid all-solid-state electrolyte (SSE) composed of chemically modified nano-silica, linear poly(trifluoroethyl methacrylate)-co-poly(poly(ethylene glycol) methyl ether methacrylate copolymer (PTFEMA-co-PPEGMA or LCP) and lithium salt is prepared and used in lithium-ion batteries (LIBs) for the first time. Nano-silica is transformed to SiO 2 -SH via esterification reaction. Then, SiO 2 -PEGMA is synthesized through click chemistry of SiO 2 -SH and PEGMA. The compatibility of the nano-SiO 2 and the LCP can be effectively improved due to the excellent dispersibility of the chemically modified nano-SiO 2 in the polymer matrix. As a result, the hybrid SSE has good thermal stability, excellent film-forming ability. Furthermore, the hybrid SSE shows superior comprehensive electrochemical properties, which makes the corresponding LiFePO 4 /Li cells have good cycling performance (the discharge capacity reaches 144 mAh g −1 at 0.3 C) and rate capability (90 mAh g −1 is reached at 1 C). Thus, the hybrid electrolyte can be a powerful SSE for high-safety and high-performance LIBs.
危险品化学品经营许可证（带存储）