A Novel High Temperature Fuel Cell Proton Exchange Membrane with Nanoscale Phase Separation Structure Based on Crosslinked Polybenzimidazole with Poly(vinylbenzyl chloride).

A semi-aromatic polybenzimidazole (DPBI) is synthesized via polycondensation of decanedioic acid (DCDA) and 3,3-diaminobenzidine (DAB) in a mixed phosphorus pentoxide/methanesulfonic acid (PPMA) solvent. Ascribing to in-situ macromolecular crosslinker of ploly((vinylbenzyl chloride) (PVBC), a robust crosslinked DPBI membrane (DPBI-xPVBC, x refers to the weight percentage of PVBC in the membrane) can be obtained. Comprehensive properties of the DPBI and DPBI-xPVBC membranes are investigated, including chemical structure, antioxidant stability, mechanical strength, PA uptake and electrochemical performances. Compared with pristine DPBI membrane, the PA doped DPBI-xPVBC membranes exhibit excellent antioxidative stability, high proton conductivity and enhanced mechanical strength. The PA doped DPBI-10PVBC membrane shows a proton conductivity of 49 mS cm-1 at 160 °C without humidification. Particularly, it reveals an enhanced H2/O2 single cell performance with the maximum peak power density of 405 mW cm-2, which is 29% higher than that of pristine DPBI membrane (314 mW cm-2). In addition, the cell is very stable in 50 h, indicating the in-situ crosslinked DPBI with a macromolecular crosslinker of PVBC is an efficient way to improve the overall performance of HT-PEMs for high performance HT-PEMFCs.

Polybenzimidazole Confined in Semi-Interpenetrating Networks of Crosslinked Poly (Arylene Ether Ketone) for High Temperature Proton Exchange Membrane.

As a traditional high-temperature proton exchange membrane (HT-PEM), phosphoric acid (PA)-doped polybenzimidazole (PBI) is often subject to severe mechanical strength deterioration owing to the "plasticizing effect" of a large amount of PA. In order to address this issue, we fabricated the HT-PEMs with a crosslinked network of poly (arylene ether ketone) to confine polybenzimidazole in semi-interpenetration network using self-synthesized amino-terminated PBI (PBI-4NH2) as a crosslinker. Compared with the pristine linear poly [2,2'-(p-oxdiphenylene)-5,5'-benzimidazole] (OPBI) membrane, the designed HT-PEMs (semi-IPN/xPBI), in the semi-IPN means that the membranes with a semi-interpenetration structure and x represent the combined weight percentage of PBI-4NH2 and OPBI. In addition, they also demonstrate an enhanced anti-oxidative stability and superior mechanical properties without the sacrifice of conductivity. The semi-IPN/70PBI exhibits a higher proton conductivity than OPBI at temperatures ranging from 80 to 180 °C. The HT-PEMFC with semi-IPN/70PBI exhibits excellent H2/O2 single cell performance with a power density of 660 mW cm-2 at 160 °C with flow rates of 250 and 500 mL min-1 for dry H2 and O2 at a backpressure of 0.03 MPa, which is 18% higher than that of OPBI (561 mW cm-2) under the same test conditions. The results indicate that the introduction of PBI containing crosslinked networks is a promising approach to improve the comprehensive performance of HT-PEMs.

[Effect of angong niuhuang pill as an adjuvant treatment on moderate or severe neonatal hypoxic-ischemic Encephalopathy].

OBJECTIVE: To evaluate the clinical efficacy and safety of angong niuhuang pill (ANP) as an adjuvant treatment on moderate or severe neonatal hypoxic-ischemic encephalopathy (NHIE). METHODS: Thirty-nine neonates with NHIE in the control group were treated with conventional treatment, and 58 in the treated group were administered orally ANP additionally, and relative indexes were observed. RESULTS: The improvement of aspects such as recovery of consciousness, muscular tension, and primitive reflex and disappearance of convulsion, in the treated group was better than that in the control group (P < 0.01). CONCLUSION: ANP as an adjuvant treatment has a definite effect on NHIE, it can promote the recovery of patients, decrease the occurrence of sequelae and with high safety, therefore, is a drug feasible for clinical application.