In 2020, the division made a new breakthrough in basic research, and 31 papers were published in the peer-reviewed leading journals, including Desalination, Chemical Engineering Journal, Journal of Membrane Science, etc. 7 Chinese patents were granted. It has undertaken more than 20 projects, including Major R&D project of the Ministry of Science and Technology, National Key Research and Development Plan of China and National Natural Science Foundation.
In order to improve the separation performance of polyimide materials for hydrogen mixed gases (H2/N2、H2/CO2、H2/CH4), we have proposed to introduce the “alicyclic structure” segments into the main chains of intrinsically microporous polyimides by copolymerization, which effectively enhanced hydrogen solubility-selectivity for their membranes, resulting in the improved hydrogen separation performance of the membranes. The favorable hydrogen separation performance in adverse/harsh environments, as well as by solution processability, desirable physical properties promised a potential large-scale separation application as membrane-based hydrogen separation materials in the future.
Fig. 1 Copolyimide with alicyclic segment
Aiming at membrane fouling deteriorating filtration performance, we have developed mussel-inspired membrane surface coating technology, and mildly grafted L-cysteine on the membrane to reduce protein adsorption; enzymes were used for specifically degrading the foulants on the membrane surface to clarify the fouling mechanisms and enhance the alkaline cleaning efficiency; a visible-light-activated photocatalytic film prepared by nitrogen doping into the lattice of TiO2 was deposited on commercial ceramic membranes via atomic layer deposition, which improved the antifouling performance and endowed self-cleaning ability, thus ensuring the long-term stable operation of the membranes.
Fig. 2 Photocatalytic film prepared via atomic layer deposition method toward self-cleaning membranes
Under the support of the STS project of Chinese Academy of Sciences (KFJ-STS-QYQYZX-017), in collaboration with Shandong Jiejing Group Co., Ltd., the novel high-shear extraction reactor, high-shear extraction technology and quality control technology were integrated, and a 1500-ton demonstration line was built and put into operation. The viscosity of the produced alginates was higher than 1500 mPa·s and the extraction ratio of alginates reached up to 85%.
Fig. 3 The process flow diagram of high-shear technology for the extraction of alginates
Fig. 4 The testing report of alginates produced by high-shear technology