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Formation of microporous polymeric membranes via thermally induced phase separation: A review

Min Liu,Shenghui Liu,Zhenliang Xu,Yongming Wei,Hu Yang

《化学科学与工程前沿（英文）》 2016年 第10卷 第1期   页码 57-75 doi: 10.1007/s11705-016-1561-7

摘要： A review of recent research related to microporous polymeric membranes formed via thermally induced phase separation (TIPS) and the morphologies of these membranes is presented. A summary of polymers and suitable diluents that can be used to prepare these microporous membranes via TIPS are summarized. The effects of different kinds of polymer materials, diluent types, cooling conditions, extractants and additive agents on the morphology and performance of TIPS membranes are also discussed. Finally new developments in TIPS technology are summarized.

关键词： polymer     microporous membrane     thermally induced phase separation    

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Protein adsorption in two-dimensional electrochromatography packed with superporous and microporous cellulose

Dongmei WANG, Guodong JIA, Liang XU, Xiaoyan DONG, Yan SUN

《化学科学与工程前沿（英文）》 2009年 第3卷 第3期   页码 229-234 doi: 10.1007/s11705-009-0213-6

摘要： Anion-exchange superporous cellulose (DEAE-SC) and microporous cellulose (DEAE-MC) adsorbents were packed in an electrochromatographic column, and the effect of external electric field (eEF) on the dynamic adsorption was investigated. The column was designed to provide longitudinal, transverse or 2-dimensional (2D) eEF. It was found that the electro-kinetic effect caused by the introduction of an electric field played an important role in the dynamic adsorption of bovine serum albumin to the adsorbents. The dynamic binding capacity (DBC) in the presence of 2D eEF was higher than in the presence of a one-dimensional eEF. The effect of flow velocity on the DBC of the two adsorbents was also demonstrated. It was found that the effect of electric field on the DEAE-MC column was more remarkable than that on the DEAE-SC column at the same flow rate, whereas the DEAE-SC column showed higher DBC and adsorption efficiency (AE) than the DEAE-MC column. With increasing flow rate, the DEAE-SC column could still offer high DBC and AE in the presence of the 2D eEF. For example, a DBC of 21.4 mg/mL and an AE of 57.7% were obtained even at a flow rate as high as 900 cm/h. The results indicate that the 2D electrochromatography packed with the superporous cellulose adsorbent is promising for high-speed protein chromatography.

关键词： electrochromatography     two-dimensional electric field     dynamic binding capacity     superporous cellulose bead     protein    

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Reactivity of Pyrogenic Carbonaceous Matter (PCM) in mediating environmental reactions: Current knowledge and future trends

Wenqing Xu, Mark L. Segall, Zhao Li

《环境科学与工程前沿（英文）》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1265-6

摘要： Abstract • Pyrogenic Carbonaceous Matter (PCM) promote both chemical and microbial synergies. • Discussion of PCM-enhanced abiotic transformation pathways of organic pollutants. • Conjugated microporous polymers (CMPs) can mimic the performance of PCM. • CMPs offer a platform that allows for systematic variation of individual properties. Pyrogenic Carbonaceous matter (PCM; e.g., black carbon, biochar, and activated carbon) are solid residues from incomplete combustion of fossil fuel or biomass. They are traditionally viewed as inert adsorbents for sequestering contaminants from the aqueous phase or providing surfaces for microbes to grow. In this account, we reviewed the recently discovered reactivity of PCM in promoting both chemical and microbial synergies that are important in pollutant transformation, biogeochemical processes of redox-active elements, and climate change mitigation with respect to the interaction between biochar and nitrous oxide (N2O). Moreover, we focused on our group’s work in the PCM-enhanced abiotic transformation of nitrogenous and halogenated pollutants and conducted in-depth analysis of the reaction pathways. To understand what properties of PCM confer its reactivity, our group pioneered the use of PCM-like polymers, namely conjugated microporous polymers (CMPs), to mimic the performance of PCM. This approach allows for the controlled incorporation of specific surface properties (e.g., quinones) into the polymer network during the polymer synthesis. As a result, the relationship between specific characteristics of PCM and its reactivity in facilitating the decay of a model pollutant was systematically studied in our group’s work. The findings summarized in this account help us to better understand an overlooked environmental process where PCM synergistically interacts with various environmental reagents such as hydrogen sulfide and water. Moreover, the knowledge gained in these studies could inform the design of a new generation of reactive carbonaceous materials with tailored properties that are highly efficient in contaminant removal.

关键词： pyrogenic carbonaceous matter     Conjugated microporous polymer     remediation     Biochar     Hydrolysis     Pollutant degradation    

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New approaches to water purification for resource-constrained settings: Production of activated biochar by chemical activation with diammonium hydrogenphosphate

Mohit Nahata, Chang Y. Seo, Pradeep Krishnakumar, Johannes Schwank

《化学科学与工程前沿（英文）》 2018年 第12卷 第1期   页码 194-208 doi: 10.1007/s11705-017-1647-x

摘要： A significant portion of the world’s population does not have access to safe drinking water. This problem is most acute in remote, resource-constrained rural settings in developing countries. Water filtration using activated carbon is one of the important steps in treating contaminated water. Lignocellulosic biomass is generally available in abundance in such locations, such as the African rain forests. Our work is focused on developing a simple method to synthesize activated biochar from locally available materials. The preparation of activated biochar with diammonium hydrogenphosphate (DAP) as the activating agent is explored under N flow and air. The study, carried out with cellulose as a model biomass, provides some insight into the interaction between DAP and biomass, as well as the char forming mechanism. Various characterization techniques such as N physisorption, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Raman spectroscopy are utilized to compare the properties between biochar formed under nitrogen and partial oxidative conditions. At a temperature of 450 °C, the loading of DAP over cellulose is systematically varied, and its effect on activation is examined. The activated biochar samples are predominantly microporous in the range of concentrations studied. The interaction of DAP with cellulose is investigated and the nature of bonding of the heteroatoms to the carbonaceous matrix is elucidated. The results indicate that the quality of biochar prepared under partial oxidation condition is comparable to that of biochar prepared under nitrogen, leading to the possibility of an activated biochar production scheme on a small scale in resource-constrained settings.

关键词： cellulose     DAP     activation     heteroatom     microporous    

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Tubes with coated and sintered porous surface for highly efficient heat exchangers

Hong Xu, Yulin Dai, Honghai Cao, Jinglei Liu, Li Zhang, Mingjie Xu, Jun Cao, Peng Xu, Jianshu Liu

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 367-375 doi: 10.1007/s11705-018-1703-1

摘要：

Surface modification is a direct and effective way to enhance the efficiency of heat exchangers. Surface modification by forming a microporous coated layer can greatly enhance the boiling heat transfer and thus achieve a high performance. In this paper, we systematically investigate the boiling behavior on a plain surface with/without sintered microporous coatings of copper powder. The results demonstrated that the sintered surface has a better performance in nucleate boiling due to the increased nucleation sites. The superheat degree is lower and the bubble departure diameter is larger for the sintered surface than for the plain surface, so the heat can be carried away more efficiently on the sintered surface. In addition, the heat transfer capacity on the sintered surface depends on both the powder size and the coating thickness for a high flux tube. The optimum heat transfer capacity can be obtained when the thickness of the microporous coating layer is 3–5 times of the sintered powder diameter. As a result, the heat transfer coefficient tube can be up to 3 times higher for the tube with a sintered surface than that with a plain surface, showing a pronounced enhancement in heat transfer and a high potential in chemical engineering industry application.

关键词： microporous coating layer     surface modification     boiling enhancement     sintering    

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标题 作者 时间 类型 操作

Formation of microporous polymeric membranes via thermally induced phase separation: A review

Min Liu,Shenghui Liu,Zhenliang Xu,Yongming Wei,Hu Yang

期刊论文

Protein adsorption in two-dimensional electrochromatography packed with superporous and microporous cellulose

Dongmei WANG, Guodong JIA, Liang XU, Xiaoyan DONG, Yan SUN

期刊论文

Reactivity of Pyrogenic Carbonaceous Matter (PCM) in mediating environmental reactions: Current knowledge and future trends

Wenqing Xu, Mark L. Segall, Zhao Li

期刊论文

New approaches to water purification for resource-constrained settings: Production of activated biochar by chemical activation with diammonium hydrogenphosphate

Mohit Nahata, Chang Y. Seo, Pradeep Krishnakumar, Johannes Schwank

期刊论文

Tubes with coated and sintered porous surface for highly efficient heat exchangers

Hong Xu, Yulin Dai, Honghai Cao, Jinglei Liu, Li Zhang, Mingjie Xu, Jun Cao, Peng Xu, Jianshu Liu

期刊论文