聚合物支载过二硫酸盐氧化芳胺为偶氮化合物的研究

大孔树脂与饱和过二硫酸钾溶液， 在室温下进行离子交换得到聚合物支载过二硫酸盐氧化剂， 容量１８ｍ ｍｏ１／ｇ该氧化剂热稳定性较好， 氧化性能温和， 能有效地将芳香伯胺氧化为偶氮化合物，

In situ One-Pot Fabrication of MoO3-x Clusters Modified Polymer Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution

Developing low-cost and high-efficient noble-metal-free cocatalysts has been a challenge to achieve economic hydrogen production.In this work,molybdenum oxides(MoO3-x)were in situ loaded on polymer carbon nitride(PCN)via a simple one-pot impregnation-calcination approach.Different from post-impregnation method,intimate coupling interface between high-dispersed ultra-small MoO3-xnanocrystal and PCN was successfully formed during the in situ growth process.The MoO3-x-PCN-X(X=1,2,3,4)photocatalyst without noble platinum(Pt)finally exhibited enhanced photocatalytic hydrogen performance under visible light irradiation(λ>420 nm),with the highest hydrogen evolution rate of 15.6μmol/h,which was more than 3 times that of bulk PCN.Detailed structure-performance revealed that such improvement in visible-light hydrogen production activity originated from the intimate interfacial interaction between high-dispersed ultra-small MoO3-xnanocrystal and polymer carbon nitride as well as efficient charge carriers transfer brought by Schottky junction formed.

Characteristics of Cyanate Ester and Fluorenyl Epoxy-Based Polymer-Ceramic Composites

In the field of highly integrated printed circuit board （PCB）, the heat resistant substrate with low water absorption is very important material. To get the resin composition for the high functional substrate material with low moisture absorption and high glass transition temperature （Tg） simultaneously, a fluorenyl ＂Cardo＂ epoxy was incorporated into novolac cyanate ester resin. As an optimum curing agent for the fiuorenyl epoxy, methyl nadic anhydride （MNA） was selected. Silica powders as fillers were added into the resin composition. The partial replacement of the cyanate ester resin with the fluorenyl epoxy could reduce the moisture absorption with keeping high glass transition temperature over 300 ℃. The laminate, which was fabricated from prepregs made with 40 wt% silica-filled resin composition and glass fabric, showed high Tg of 317 ℃ and low moisture absorption of 0.57%.

Pattern transition and sluggish cracking of colloidal droplet deposition with polymer additives

Drying of colloidal droplets often develops versatile depositions.We study the drying deposition of both colloidal droplets containing silica nanoparticles and the silica colloidal droplets with polyethylene oxide(PEO) additives.We focus on the effect of polymer additives on the deposition formation and the cracking dynamics by using in-situ microscope observation.With PEO additives,a transition from ring-like deposition to uniform deposition is observed,and the cracking dynamics is greatly reduced.The PEO additives enhance the adsorption of particles at the air-water interface,thus forming the network structure at the interface which blocks the outward capillary flow.This contributes to the uniform deposition.Meanwhile,the multi-distribution of the aggregates size enhances the non-homogeneity of the drying film and consequently results in multi-nucleation of cracks.This reduces the stress accumulation that drives the crack propagation and may be responsible for the sluggish cracking dynamics.

Microporous polymer based on hexaazatriphenylene-fused triptycene for CO2 capture and conversion

Chemical conversion of carbon dioxide(CO2)to value-added useful chemicals like cyclic carbonates represents one potential solution to climate warming.Here,a kind of porous organic polymer(HAT-TP)with large surface area and excellent carbon dioxide uptake capacity is prepared via a condensation reaction to introduce hexaazatriphenylene(HAT)units into triptycene(TP)-based microporous polymer.HAT-TP can coordinate with zinc ions,and the resulting polymer(Zn/HAT-TP)can be utilized as an efficient recyclable catalyst for chemical conversion of CO2 into cyclic carbonates with epoxides.