Applied Technology

The Breakthrough of Shape-memory Polymers Achieved

There are many applications of Shape-memory polymers (SMPs) in the field of bio-medical, structural parts and textile, which make the SMP one of the hottest topics in both academic and industrial society. Prof. Zhu Jin’s group at the Ningbo Institute of Materials Technology and Engineering (NIMTE) had developed a bio-based SMP material by substituting petroleum based chain extender with rosin based one. With the careful molecular design, they constructed highly incompatible hard and soft segments along the polymer chain and obtained shape-memory polyurethane (SMPU) with supreme shape recovery property. This SMPU can ‘remember’ 96% of original length after 1000% strain treatment, and is able to reach 960% of the maximum shape recovery, which is more than two times of the maximum value reported as 400%. All the above results had been published in Journal of Materials Chemistry A (2013, 1(10): 3263-3267.) under the Royal Society of Chemistry, and patents aimed to protect this technique had been applied. As for the next step, Prof. Zhu’s Group will continue to follow the idea of molecular design and multi-scale structure control, in order to develop the full bio-based SMPU.

Research Review on New GTL Catalysis

A joint research on the methane/CO2 reforming and low-temperature methanol synthesis conducted by Prof. Noritatsu Tsubaki (Thousand Talents Program awarded by the Recruitment Program of Global Experts) and Prof. Tan Yisheng of the Institute of Coal Chemistry, CAS, has attrated more attention from peer circles worldwide. Recently, an invited review article titled “An Introduction of CO2 Conversion by Dry Reforming with Methane and New Route of Low-Temperature Methanol Synthesis” was published by Accounts of Chemical Research (DOI: 10.1021/ar300217j; IF: 21.64). Firstly, this review introduced a simple but useful method to prepare bimodal catalysts, where small pores were formed inside large ones during the self-organization of nanoparticles from solution. The large pores of bimodal catalysts could enhance the mass transfer rate, while small pores provided large surface areas to disperse active metallic nanoparticles, therefore avoiding the sintering and aggregation of metal catalyst during reaction. These bimodal catalysts in GTL process will effectively promote the conversion of CO2 and CH4 to form syngas (CO+H2), simultaneously reducing the reactor size and equipment investment. Secondly, this review article demonstrated a novel low-temperature methanol synthesis method. Researchers previously worked on low-temperature methanol synthesis were always focusing on strongly basic catalysts, such as the mixture of NaH, alcohol and acetate. But trace amounts of CO2 and H2O in the syngas deactivated basic catalysts quickly. Unlike previous studies, Prof. Tsubaki presented a new low-temperature methanol synthesis method, in which the CO2 and H2O are utilized as intermediates. This new method was operated at low temperature and low pressure (443 K and 3.0 MPa). The CO conversion in this process reached up to 100% with methanol selectivity more than 98%. Especially, it was not necessary to remove the CO2 and H2O in syngas, which will substantially lower the production cost of methanol. The reaction mechanism studies on this new low-temperature methanol synthesis method revealed that methanol acts as not only product but also homogenous co-catalyst and heat-absorption solvent concurrently. The adsorbed formate species reacted with alcohols to yield ester species at low temperature, followed by the hydrogenation of ester on metallic Cu to be converted into methanol. Based on this low-temperature methanol synthesis method, Professor Tsubaki had further developed another new supercritical low-temperature methanol synthesis route, realizing the highest space-time yield of methanol up to 1200g/kgcat.·h, much better than other industrialized catalysts. The above original research work had been published by Chem. Comm., J. Catal., AIChE J., ChemCatChem, etc., receiving peer attentions widely.