粉末状炭气凝胶的结构调控及其在高电压水系超级电容器中的应用

在成功合成粉末状炭气凝胶(PCA)的基础上,详细研究了PCA构筑单元(高分子纳米球)粒径、羰基交联时间和羰基交联温度等制备条件与PCA纳米结构的关联性,并探索了PCA在高电压水系超级电容器中的应用。实验结果表明,高分子纳米球粒径、羰基交联时间和羰基交联温度对PCA的纳米结构具有显著的影响,所得PCA均具有优良的三维纳米网络结构,其网络单元可在25~100 nm之间进行剪裁,BET比表面积可在392~767 m^2g^(-1)范围内进行调控。由于具有丰富的孔隙率和合理的三维网络层次孔结构,这类PCA材料在1.8 V Na_2SO_4水系超级电容器中显示出高的比电容量、电容保持率以及高效的电化学活性表面,能量密度显著优于其1.0 VKOH水系超级电容器。

Preparation and Antibacterial Activity of Copolymer of Methacryloxyethyldimethyl Dodecyl Ammonium Bromide/Acrylamide

Copolymers PMDAB-co-AA with excellent antibacterial activity were designed and prepared（MDAB/AA=methacryloxyethyldimethyl dodecyl ammonium bromide with acrylamide）.The chemical structures of the copolymers were characterized by Fourier transform infrared（FTIR）,1 H NMR,13 C NMR and chemical titration.The antimicrobial activities and kinetics of the copolymer against E.coli and S.aureus were examined by viable cell counting method.The compositions of the copolymers could be easily controlled by the feed molar ratio of MDAB to AA.Furthermore,the highest antibacterial activity was achieved when the molar fraction of MDAB was in a range of 5%―20%,and the killing rate reached 100% under the test conditions.In addition,the antibacterial activity of PMDAB-co-AA was maintained and stable without any loss after 15 times of repeated usage.It was proved that the PMDAB-co-AA samples targeted at cell membrane,and caused serious damage to cell integrity and inner membrane permeation.The surrounding conditions,such as pH and inorgainc salts concentrations（CaCl2 or NaCl）,also affected their antibacterial activities.

Synthesis and Antibacterial Action of Poly(DMAEMA-BC) with Various Molecular Weights

Antibacterial polymers of dimethylaminoethyl methacrylate benzyl ammonium chloride（DMAEMA-BC） with various molecular weights（Mws） were prepared under controlling radical polymerization conditions. The Mws of these polymers were determined by means of static multiangle laser light scattering and viscosity method. A Mark-Houwink equation was established to be [η]=0.154M0.764 for the Mw evaluation of poly（DMAEMA-BC）s. The effects of the Mws of these poly（DMAEMA-BC）s on their antibacterial activities against E. coli and S. aureus were investigated by various methods including viable cell counting, electrical conductivity titration, intracellular constituent leakage tests and electron microscopy. Our results indicate that the antibacterial efficiency of DMAEMA-BC was significantly enhanced after the monomers were polymerized into a polymer and increased obviously with the Mws,as a result of the increase of charge density. Further investigation of the molecular basis underlying the anti-bacterial role of these polymers revealed that poly（DMAEMA-BC） promoted the release of potassium ion from the membrane of bacterial cells and the release increased significantly with the Mws of the polymers used.

粉末状聚苯乙烯气凝胶的结构调控及其液相吸附性能初探

在成功合成粉末状聚苯乙烯气凝胶(PPA)的基础上,详细研究了高分子纳米球构筑单元的结构和Friedel-Crafts超交联条件对PPA纳米结构的影响,初步考察了PPA对甲基红和亚甲基蓝的液相吸附性能。实验结果表明,PPA呈现三维纳米网络结构,其纳米球网络单元粒径约为30nm,且纳米球之间的堆叠形成大孔和中孔,从而具有独特的微孔-中孔-大孔层次化分布的孔结构特征。通过控制反应条件,其BET比表面积和总孔容可分别在201m^2·g^(-1)~702m^2·g^(-1)和0.16cm^3·g^(-1)~1.29cm^3·g^(-1)范围内调控。PPA自身较强的疏水性和丰富的孔隙结构赋予其对正辛烷中的甲基红和水溶液中的亚甲基蓝良好的吸附性能。