Shengbo Zhu,Wei Li,Bingyang Lu,Weixing Chen,Wenzhi Zhang,Xiaoling Niu,Xinbing Chen,Zhongwei An
Two series of terminal epoxy compounds, PmOBC (m = 1, 2, 3, 4) and P1OBEn (n = 6, 8, 10, 12), were synthesized for investigating the effect of epoxidation on mesomorphic and thermal stabilities. Molecular polarization and configuration obtained by DFT calculations can provide theoretical perspective. In addition, thermal stability is evaluated by the combination of DSC , TGA , and 1 H NMR. Compared with the corresponding alkenyl compounds, epoxidation reduces the molecular dipole moment and increase the molecular steric effect , which is not conducive to the formation of LC phases, but the reduced intramolecular energy may be helpful to improve thermal stability. Therefore, these terminal epoxy LCs are very promising for application in display devices requiring extremely high-temperature environments.
Rongzhao Jia,Shenli Jia,Jiajian Zhang,Yongpeng Mo,Zongqian Shi
A method for in situ fabrication of Al@C nanocomposite energetic additives through pulsed discharge in liquid cyclohexane has been proposed. The obtained Al@C nanocomposites consist of large aluminum nanoparticles (over 100 nm) enveloped by fullerenes and a carbon matrix with smaller aluminum particles (under 100 nm) embedded within. DSC–TGA curves indicate that the heat release of Al@C is higher than that of micron-sized and nano-sized aluminum particles. Al@C nanocomposites effectively reduce the ignition delay for liquid fuels. The energy efficiency of this method is much higher than that of continuous arc ablation, with a yield of up to 2.5 mg/min. This method allows for the simple, convenient, and safe fabrication of energetic additives, presenting a promising prospect for large-scale industrial production.