Dalian University of Technology

Yan Dai

Gaohong He

Xuehua Ruan

Xiaoming Yan

Xiaobin Jiang

Xiangcun Li

Xuemei Wu

Wu Xiao

Ning Zhang

Yan Xu

Xiaozhou Wang

Panpan Mi

Fujun Cui

Minggang Guo

Xiaohang Yang

Wanting Chen

Xuxing Liao

Tiantian Li

The present invention belongs to the field of alkaline polymer electrolyte membranes, and relates to a comb-shaped structure polybenzimidazole anion exchange membrane with high conductivity and preparation method thereof. In the invention, firstly, polybenzimidazole is grafted with the non-cationic side chains to the max grafting rate to synthesize the de-protonated comb-shaped polybenzimidazole material, avoiding the N—H in benzimidazole forms ionic binding with cationic functional groups, which will reduce the reactivity and mobility of cationic groups; then react de-protonated comb-shaped polybenzimidazole with quaternization reagent to attach the pendent side chain with cationic functional groups, making it easy to aggregate to form ion clusters and hydrophilic/hydrophobic microphase separation. The anion exchange membrane prepared in this invention has excellent conductivity, mechanical properties and alkaline stability.

Comb-shaped structure polybenzimidazole anion exchange membrane with high conductivity and preparation method thereof

A separation and purification coupled process with a high helium yield and diversified products is provided. The process is as follows. Firstly, a low-concentration helium-containing gas after being pressurized and pre-treated enters a two-stage and two-section membrane separation unit to produce a helium product with a medium concentration by concentrating stage by stage through the membrane separation unit. A part of the helium with medium concentration enters an adsorption unit for further concentration to produce a helium product above grade A.

Separation and purification coupled process with high helium yield and diversified products

The present invention provides a surface modification method based on the polymerization and cross-linking solidification of dopamine and/or its derivatives, which belongs to the technical field about composite material fabrication. The principle of dopamine polymerization and the formation process of polydopamine coating layer are the foundation of the present invention. This innovative method is established after deeply analyzing the failure mechanism of polydopamine coating layer in severe environments, such as organic solvents and acidic/alkalic environments. The critical work is finding out an eligible cross-linking agent which could react with the active functional groups in polydopamine. After cross-linking reaction, the soluble low-molecular-weight dopamine oligomers could be transformed into the insoluble three-dimensional stereographic networks. In this instance, the interaction between polydopamine molecules, and the adhesion between polydopamine coating layer and substrate materials, can be significantly strengthened. After the cross-linking solidification, the hydrophilic polydopamine coating layer could be stable and effective for long-term utilization in severe environments, e.g., organic solvents and acidic/alkalic environments, and thereby expand the application scope of the surface modification method based on dopamine polymerization greatly.

Surface modification method based on polymerization and cross-linking solidification of dopamine and/or derivatives thereof

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Liaoning, China

Yan Dai