资源类型

期刊论文 529

年份

2024 2

2023 50

2022 53

2021 41

2020 39

2019 26

2018 28

2017 28

2016 17

2015 11

2014 35

2013 12

2012 17

2011 21

2010 18

2009 30

2008 33

2007 31

2006 1

2005 9

展开 ︾

关键词

膜分离 5

三峡工程 2

三相界面 2

二氧化碳 2

低成本 2

光催化 2

反渗透 2

残余应力 2

相变 2

聚偏氟乙烯 2

2

-10#柴油微乳剂 1

12相整流 1

3D支架平台 1

3D生物打印 1

Anderson 模型 1

CCS 1

CO 1

CO2分离 1

展开 ︾

检索范围:

排序: 展示方式:

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 720-730 doi: 10.1007/s11705-021-2098-y

摘要: A non-toxic and environmentally safe diluent, acetyl tributyl citrate, was employed to prepare poly(vinylidene fluoride)-co-hexafluoropropylene membranes via thermally induced phase separation. Effects of the polymer concentration on the phase diagram, membrane morphology, hydrophobicity, pore size, porosity and mechanical properties (tensile stress and elongation at break) were investigated. The results showed that the pore size and porosity tended to decrease with increasing polymer concentration, whereas the contact angle, liquid entry pressure and mechanical properties showed the opposite trend. In direct contact membrane distillation operation with 3.5 wt-% sodium chloride solution as the feed solution, the prepared membranes performed high salt rejection (>99.9%). Furthermore, the prepared membranes retained excellent performance in long-term stability tests regarding the permeate flux and salt rejection.

关键词: poly(vinylidene fluoride)-co-hexafluoropropylene     thermally induced phase separation     non-toxic diluent     direct contact membrane distillation    

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    

热致相分离法高性能聚偏氟乙烯中空纤维膜先进制备技术及应用

唐元晖,林亚凯,王晓琳

《中国工程科学》 2014年 第16卷 第12期   页码 24-34

摘要:

膜分离技术已经成为国际上市政污水和工业废水处理的核心技术。十年来清华大学化学工程系在先进膜材料制备及应用技术研究上开展了大量工作,以膜材料配方设计、膜材料先进制造、膜组件设计与应用为主线,突破多个技术难题和瓶颈,实现了热致相分离(TIPS)法高性能聚偏氟乙烯(PVDF)中空纤维膜的工业化。首先,基于对TIPS法成膜过程的热力学及动力学研究,制备出具有大通量、高强度、亲水性好的PVDF微孔膜;接着,有机结合材料加工和单元操作,形成PVDF中空纤维膜先进制造技术;最后针对不同的工业环境和市政要求,开发出不同规格的高性能膜组件。研究成果表明TIPS法突破了传统非溶剂致相转化法的限制,可以作为市政污水和工业废水处理的首选膜材料制备技术。

关键词: 热致相分离     聚偏氟乙烯     水处理     膜制备    

porous membranes with micro-nano composite structure using a facile atomization-assisted nonsolvent inducedphase separation method

《化学科学与工程前沿(英文)》 2022年 第16卷 第8期   页码 1268-1280 doi: 10.1007/s11705-022-2143-5

摘要: The micro-nano composite structure can endow separation membranes with special surface properties, but it often has the problems of inefficient preparation process and poor structural stability. In this work, a novel atomization-assisted nonsolvent induced phase separation method, which is also highly efficient and very simple, has been developed. By using this method, a bicontinuous porous microfiltration membrane with robust micro-nano composite structure was obtained via commercially available polymers of polyacrylonitrile and polyvinylpyrrolidone. The formation mechanism of the micro-nano composite structure was proposed. The microphase separation of polyacrylonitrile and polyvinylpyrrolidone components during the atomization pretreatment process and the hydrogen bonding between polyacrylonitrile and polyvinylpyrrolidone molecules should have resulted in the nano-protrusions on the membrane skeleton. The membrane exhibits superhydrophilicity in air and superoleophobicity underwater. The membrane can separate both surfactant-free and surfactant-stabilized oil-in-water emulsions with high separation efficiency and permeation flux. With excellent antifouling property and robust microstructure, the membrane can easily be recycled for long-term separation. Furthermore, the scale-up verification from laboratory preparation to continuous production has been achieved. The simple, efficient, cost-effective preparation method and excellent membrane properties indicate the great potential of the developed membranes in practical applications.

关键词: atomization     nonsolvent induced phase separation     bicontinuous porous structure     micro-nano composite structure     oil-water separation    

Phase separation time/temperature dependence of thermoplastics-modified thermosetting systems

ZHANG Xiujuan, XU Yuanze, YI Xiaosu

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 276-285 doi: 10.1007/s11705-008-0057-5

摘要: The cure-induced phase separation processes of various thermoplastics(TP)-modified thermosetting systems which show upper critical solution temperature (UCST) or lower critical solution temperature (LCST) were studied with emphasis on the temperature dependency of the phase separation time and its potential application in the cure time-temperature processing window. We found that the phase separation time/temperature relationship follows the simple Arrhenius equation. The cure-induced phase separation activation energy (ps) generated from the linear fitting of the Arrhenius equation is irrelevant to the detection means of phase separation time. We also found that (ps) is insensitive to TP content, TP molecular weight and curing rate, but it changes with the cure reaction kinetics and the chemical environment of the systems. With the established phase separation time-temperature dependence relation, we can easily establish the whole cure time-temperature transformation (TTT) diagram with morphology information which is a useful map for the TP/TS composites processing industry.

关键词: separation time-temperature     temperature dependency     cure-induced     separation activation     temperature    

Phase separation in cGAS-STING signaling

《医学前沿(英文)》   页码 855-866 doi: 10.1007/s11684-023-1026-6

摘要: Biomolecular condensates formed by phase separation are widespread and play critical roles in many physiological and pathological processes. cGAS-STING signaling functions to detect aberrant DNA signals to initiate anti-infection defense and antitumor immunity. At the same time, cGAS-STING signaling must be carefully regulated to maintain immune homeostasis. Interestingly, exciting recent studies have reported that biomolecular phase separation exists and plays important roles in different steps of cGAS-STING signaling, including cGAS condensates, STING condensates, and IRF3 condensates. In addition, several intracellular and extracellular factors have been proposed to modulate the condensates in cGAS-STING signaling. These studies reveal novel activation and regulation mechanisms of cGAS-STING signaling and provide new opportunities for drug discovery. Here, we summarize recent advances in the phase separation of cGAS-STING signaling and the development of potential drugs targeting these innate immune condensates.

关键词: biomolecular condensates     phase separation     cGAS-STING pathway     cGAS     STING     cGAMP     interferon    

Microfluidic production of liposomes through liquid–liquid phase separation in ternary droplets

《化学科学与工程前沿(英文)》 2022年 第16卷 第6期   页码 1017-1022 doi: 10.1007/s11705-021-2118-y

摘要: Liposomes, the self-assembled phospholipid vesicles, have been extensively used in various fields such as artificial cells, drug delivery systems, biosensors and cosmetics. However, current microfluidic routes to liposomes mostly rely on water-in-oil-in-water double emulsion droplets as templates, and require complex fabrication of microfluidic devices, and tedious manipulation of multiphase fluids. Here we present a simple microfluidic approach to preparing monodisperse liposomes from oil-in-water droplets. For demonstration, we used butyl acetate-water-ethanol ternary mixtures as inner phase and an aqueous solution of surfactants as outer phase to make oil-in-water droplets, which can evolve into water-in-oil-in-water double emulsion droplets by liquid–liquid phase separation of ternary mixtures. Subsequently, the resultant water-in-oil-in-water droplets underwent a dewetting transition to form separated monodisperse liposomes and residual oil droplets, with the assistance of surfactants. The method is simple, does not require complex microfluidic devices and tedious manipulation, and provides a new platform for controllable preparation of liposomes.

关键词: microfluidics     liposomes     ternary droplets     phase separation    

NIPS法聚偏氟乙烯超滤膜的制备与应用

吕晓龙,武春瑞,张昊,赵丽华

《中国工程科学》 2014年 第16卷 第12期   页码 35-45

摘要:

非溶剂相分离(NIPS)制膜方法是20世纪60年代发明的一种高效的制膜方法。利用该法制备的不对称膜结构赋予膜优异的选择渗透性能,膜孔结构易于调控,已经成为当前聚合物分离膜研究及商业化生产中普遍采用的方法。聚偏氟乙烯(PVDF)具有优异的综合性能,成膜性能佳,可利用NIPS法制膜。NIPS法PVDF膜的研制、膜结构控制方法及应用研究受到国际膜研究者广泛关注,是分离膜领域热点之一。本文分别针对NIPS法PVDF超滤膜制备的相分离原理研究、膜结构控制方法及膜应用研究等关键研究进展作简要介绍。

关键词: 非溶剂致相分离     聚偏氟乙烯     超滤膜     相分离原理     膜结构与性能     膜应用    

Functional flax fiber with UV-induced switchable wettability for multipurpose oil-water separation

《环境科学与工程前沿(英文)》 2022年 第16卷 第12期 doi: 10.1007/s11783-022-1588-6

摘要:

● A PAA-ZnO-HDTMS flax fiber with UV-induced switchable wettability was developed.

关键词: Flax fiber     Switchable wettability     ZnO-HDTMS coating     Oil-water separation    

Improved film evaporator for mechanistic understanding of microwave-induced separation process

Xin Gao, Dandan Shu, Xingang Li, Hong Li

《化学科学与工程前沿(英文)》 2019年 第13卷 第4期   页码 759-771 doi: 10.1007/s11705-019-1816-1

摘要: Microwave-induced film evaporation separation process has been reported recently to separate the polar/nonpolar mixture. However, the efficiency of the separation is still too low for practical applications, which requires further enhancement via different strategies such as optimization design of evaporator structure. In addition the depth understanding of the separation mechanisms is great importance for better utilization of the microwave-induced separation process. To carry out these investigations, a novel microwave-induced falling film evaporation instrument was developed in this paper. The improvement of the enhancement effect of microwave-induced separation was observed based on the improved film evaporator. The systematic experiments on microwave-induced separation with different binary azeotropic mixtures (ethanol-ethyl acetate system and dimethyl carbonate (DMC)-H O system) were conducted based on the new evaporator. For the ethanol-ethyl acetate system, microwave irradiation shift the direction of evaporation separation at higher ethanol content in the starting liquid mixture. Moreover, for DMC-H O system microwave-induced separation process broke through the limitations of the traditional distillation process. The results clearly demonstrated the microwave-induced evaporation separation process could be commendably applied to the separation of binary azeotrope with different dielectric properties. Effects of operating parameters are also investigated to trigger further mechanism understanding on the microwave-induced separation process.

关键词: process intensification     microwave     falling film evaporation     separation     azeotrope    

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0705-3

摘要: As a nondestructive testing technique, terahertz time-domain spectroscopy technology is commonly used to measure the thickness of ceramic coat in thermal barrier coatings (TBCs). However, the invisibility of ceramic/thermally grown oxide (TGO) reflective wave leads to the measurement failure of natural growth TGO whose thickness is below 10 μm in TBCs. To detect and monitor TGO in the emergence stage, a time of flight (TOF) improved TGO thickness measurement method is proposed. A simulative investigation on propagation characteristics of terahertz shows the linear relationship between TGO thickness and phase shift of feature wave. The accurate TOF increment could be acquired from wavelet soft threshold and cross-correlation function with negative effect reduction of environmental noise and system oscillation. Thus, the TGO thickness could be obtained efficiently from the TOF increment of the monitor area with different heating times. The averaged error of 1.61 μm in experimental results demonstrates the highly accurate and robust measurement of the proposed method, making it attractive for condition monitoring and life prediction of TBCs.

关键词: thermal barrier coatings     thermally grown oxide     terahertz spectroscopy     time of flight    

Numerical study and control method of interaction of nucleation and boundary layer separation in condensing

Liansuo AN , Zhi WANG , Zhonghe HAN ,

《能源前沿(英文)》 2009年 第3卷 第3期   页码 254-261 doi: 10.1007/s11708-009-0047-4

摘要: The spontaneous nucleation flow in turbine cascade was numerically studied. The model was implemented within a full Navier–Stokes viscous flow solution procedure and the process of condensation was calculated by the quadrature method of moments that shows good accuracy with very broad size distributions. Results were presented for viscous and inviscous flow, showing the influence of boundary layer separation and wake vortices on spontaneous nucleation. The results show that the degree of flow separation in wet steam flow is greater than that in superheated steam flow due to condensation shock and that the loss cannot be neglected. Furthermore, the impact of boundary layer separation and wake vortices on velocity profiles and its implications for profile loss were considered. The calculations showed that layer separation and wake vortices influence nucleation rate, leading to different droplet distributions. A method for controlling homogeneous nucleation and for reducing degree of flow separation in high-speed transonic wet steam flow was presented. The liquid phase parameter distribution is sensitive to the suction side profile of turbine cascade, which impacts the nucleation rate distribution leading to different droplet distributions and affects the degree of flow separation. The numerical study provides a practical design method for turbine blade to reduce wetness losses.

关键词: wet steam     two-phase flow     spontaneous condensation     numerical simulation     flow separation     profile loss    

通过介导相分离制备的纳米结构W-Cu基复合材料的性能 Article

侯超, 吕皓, 赵治, Xintao Huang, 韩铁龙, Junhua Luan, Zengbao Jiao, 宋晓艳, Zuoren Nie

《工程(英文)》 2023年 第26卷 第7期   页码 173-184 doi: 10.1016/j.eng.2022.09.017

摘要:

The challenge of fabricating nanostructured W–Cu composites by powder metallurgy has been solved by means of modulated phase separation. A hierarchically nanostructured (HN) W–Cu composite was prepared using intermediary Al through sluggish asynchronous phase separation. In addition to a dual network composed of a Cu phase and the W–Cu nanostructure, dense Al-containing nanoprecipitates with a body-centered cubic (bcc) structure are distributed in the W matrix. Compared with a pristine W/Cu interface, the newly formed W/Cu interfaces modulated by Al and the coherent W/Al-containing particle interfaces possess lower energy and enhanced bonding strength due to efficient electron transfer and strong coupling interactions. With a large number of stable heterogeneous interfaces and a "self-locking" geometry, the HN W–Cu composite exhibits excellent resistance against plastic deformation. The combination of the presented composite's hardness and compressive strength outperforms all other sintered W–Cu composites with the same Cu content. Under a reciprocating sliding load, the reactive Al prevents excessive oxidation. The excellent synergy of the hardness and toughness of the friction-induced surface endows the HN composite with high abrasion resistance. This study provides a new strategy to modulate the structure and energy state of interfaces in metallic composites containing immiscible components in order to achieve high mechanical performance.

关键词: Immiscible-component composite     Phase separation     Nanostructure     Mechanical properties     Interface modulation    

Purification of ice structuring protein complexes from winter wheat using Triton X-114 phase partitioning

Huaneng XU, Haiying CHEN, Weining HUANG,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 383-385 doi: 10.1007/s11705-009-0249-7

摘要: Ice structuring proteins (ISPs) isolated from the cold-acclimated plants have a great potential in improving the quality of frozen foods. The purification of ISP complexes from winter wheat was achieved using an aqueous two-phase system of Triton X-114. The highly reactive phenols were removed, and the ISP complexes remained in the aqueous phase after phase separation. The ISP complexes treated by this procedure retained higher thermal hysteresis activity than those treated by ammonium sulfate method. The phase separation technique provides a simple and mild way for removing phenols from ISP complexes.

关键词: separation technique     thermal hysteresis     cold-acclimated     purification     X-114    

Utilizing melt crystallization fundamentals in the development of a new tabletting technology

Ahmed ABOUZEID,Sandra PETERSEN,Joachim ULRICH

《化学科学与工程前沿(英文)》 2014年 第8卷 第3期   页码 346-352 doi: 10.1007/s11705-014-1443-9

摘要: Increasing production effeciency and lowering costs are some of the many advantages melt crystallization technology offers over the conventional methodology of tabletting. A normal tablet consists of a pure shell or a coat and a separate core constituting the pharmaceutical active ingredient. Great emphasis is put on the purity of the shell since its purpose is to solely protect and deliver the active ingredient to its target. Melt crystallization is a purification (separation) process. It is discussed here for its ability to produce coated tablets, by separating the “coating” material from the “to be coated” material coming from one molten mixture. Molten drops of lutrol-ibuprofen mixture are produced using the drop forming technique. The subsequent analysis involves proving and quantifying the phase separation (coat purity). The mechanism of a crystallizing drop is shown as direct evidence of the ongoing process. Moreover, solidified tablet batches are analyzed for the purity of their coating by measuring the ibuprofen concentration. This optimization process is carried out through multiple stages of development and condition enhancements in order to produce the most pure tablet coating. As a result, a trial showing an almost purely coated tablet is presented here.

关键词: phase separation     melt crystallization     tablets     process optimization    

标题 作者 时间 类型 操作

Poly(vinylidene fluoride--hexafluoro propylene) membranes prepared via thermally induced phase separation

期刊论文

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

热致相分离法高性能聚偏氟乙烯中空纤维膜先进制备技术及应用

唐元晖,林亚凯,王晓琳

期刊论文

porous membranes with micro-nano composite structure using a facile atomization-assisted nonsolvent inducedphase separation method

期刊论文

Phase separation time/temperature dependence of thermoplastics-modified thermosetting systems

ZHANG Xiujuan, XU Yuanze, YI Xiaosu

期刊论文

Phase separation in cGAS-STING signaling

期刊论文

Microfluidic production of liposomes through liquid–liquid phase separation in ternary droplets

期刊论文

NIPS法聚偏氟乙烯超滤膜的制备与应用

吕晓龙,武春瑞,张昊,赵丽华

期刊论文

Functional flax fiber with UV-induced switchable wettability for multipurpose oil-water separation

期刊论文

Improved film evaporator for mechanistic understanding of microwave-induced separation process

Xin Gao, Dandan Shu, Xingang Li, Hong Li

期刊论文

Time of flight improved thermally grown oxide thickness measurement with terahertz spectroscopy

期刊论文

Numerical study and control method of interaction of nucleation and boundary layer separation in condensing

Liansuo AN , Zhi WANG , Zhonghe HAN ,

期刊论文

通过介导相分离制备的纳米结构W-Cu基复合材料的性能

侯超, 吕皓, 赵治, Xintao Huang, 韩铁龙, Junhua Luan, Zengbao Jiao, 宋晓艳, Zuoren Nie

期刊论文

Purification of ice structuring protein complexes from winter wheat using Triton X-114 phase partitioning

Huaneng XU, Haiying CHEN, Weining HUANG,

期刊论文

Utilizing melt crystallization fundamentals in the development of a new tabletting technology

Ahmed ABOUZEID,Sandra PETERSEN,Joachim ULRICH

期刊论文