复合增塑剂改性PBAT/淀粉薄膜的性能

以玉米淀粉、聚己二酸/对苯二甲酸丁二酯(PBAT)为主要原材料,甘油为主增塑剂,山梨醇、聚乙烯醇200(PEG200)、二甲基甲酰胺等为辅增塑剂,通过挤出机造粒再吹塑方法制成淀粉填充PBAT薄膜.研究对比了不同增塑剂在淀粉填充PBAT材料中的塑化效果,同时探究了不同塑化剂对复合薄膜力学性能、表面粗糙度、吸水率、溶出率及...     

Two-dimensional MXene hollow fiber membrane for divalent ions exclusion from water

Two-dimensional material membranes with fast transport channels and versatile chemical functionality are promising for molecular separation.Herein,for the first time,we reported design and engineering of two-dimensional Ti3C2Tx MXene (called transition metal carbides and nitrides) membranes supported on asymmetric polymeric hollow fiber substrate for water desalination.The membrane morphology,physic-ochemical properties and ions exclusion performance were systematically investigated.The results demonstrated that surface hydrophilicity and electrostatic repulsion and size sieving effect of interlayer channels synergistically endowed the MXene hollow fiber membrane with fast water permeation and efficient rejection of divalent ions during nanofiltration process.     

Minimising non-selective defects in ultrathin reduced graphene oxide membranes with graphene quantum dots for enhanced water and NaCl separation

Reduced graphene oxide (rGO) membranes have been intensively evaluated for desalination and ionic sieving applications,benefiting from their stable and well-confined interlayer channels.However,rGO membranes generally suffer from low permeability due to the high transport resistance resulting from the narrowed two-dimensional (2D) channels.Although high permeability can be realized by reducing membrane thickness,membrane selectivity normally declines because of the formation of non-selective defects,in particular pinholes.In this study,we demonstrate that the non-selective defects in ultrathin rGO membranes can be effectively minimised by a facile posttreatment via surface-deposition of graphene quantum dots (GQDs).The resultant GQDs/rGO membranes obtained a good trade-off between water permeance (14 L·m-2·h-1·MPa-1) and NaCl rejection (91％).This work provides new insights into the design of high quality ultrathin 2D laminar membranes for desalination,molecular/ionic sieving and other separation applications.     

Photocatalytic degradation of tetracycline hydrochloride with visible light-responsive bismuth tungstate/conjugated microporous polymer

Conjugated microporous polymer (CMP) is an emerging organic semiconductor with π-conjugated skele-tons,and the bandgap of CMP can be flexibly modulated to harvest visible light.Based on the diversity and adjustability of monomers in CMP,we designed and synthesized donor-accepter (D-A) type BTN-CMP through Sonogashira-Hagihara cross-coupling polymerization,further in-situ constructing series of inorganic/organic Z-scheme BW/BTN-n composite in the presence of Bi2WO6.After optimization,the tetracycline hydrochloride (Co =10 mg·L-1) degradation efficiency reached 84％ with BW/BTN-2 as cata-lyst in 90 min under visible light irradiation,the apparent rate constant k1 is 0.017 min-1,which is 1.7 and 5.7 times higher than bare Bi2WO6 and BTN-CMP.X-ray photoelectron spectra and UV-Vis diffuse spectra showed that the enhanced photocatalytic activity originated from the tight heterojunction between Bi2WO6 and BTN-CMP,which can extend the light absorption range and facilitate the separation and transport of photogenerated charges in the interface of heterojunction.The active species trapping experiments and electron spin resonance technique revealed that h+ was the dominant active species during the photodegradation process of tetracycline hydrochloride (TCH).The present study demon-strated the feasibility to construct inorganic/organic composite for the photocatalytic degradation of environmental pollutants.     

复合固体推进剂填料/基体脱湿研究进展

概述了复合固体推进剂脱湿的表征方法,分析了各表征方法的优缺点,以及各表征方法适合研究脱湿的范畴,提出了可能的改进方向.概述了各因素对脱湿的影响:内因包括黏合剂基体模量,固体大颗粒含量、粒度、形貌等;外因包括测试温度、拉伸速率、应变率、湿热老化、环境压强等.提出对应的减少各因素影响脱湿发生的方法.     

3D石墨烯/导电聚合物气凝胶复合材料在超级电容器中的研究进展

分析了近年来超级电容器电极材料尤其是3D石墨烯/导电聚合物气凝胶复合电极材料在超级电容器方面的研究进展,详细介绍了目前3D石墨烯气凝胶的制备方法,总结了3D石墨烯/导电聚合物气凝胶复合材料的不足和在存储领域的发展方向.     

多级复合芯结构的强化沸腾传热研究

采用固相烧结技术制备了均匀多孔层、复合16芯和复合32芯三种多孔结构,并且建立了池沸腾传热测试系统来研究不同芯数量、粒径与结构高度对多孔结构沸腾传热性能的影响。实验结果表明,在测试范围内复合层高1 mm的多孔复合32芯结构传热性能较强,临界热通量(CHF)最高为386 W/cm²,传热系数最高达到9.5 W/(cm²·K)。同时利用高速摄影观察气泡行为来研究强化沸腾传热机理。可视化数据表明,相比于光滑表面,在高热通量下多孔复合表面上气泡周期更短,脱离更快,气泡的离开带来了更多的液体补充,进而不断提升传热性能,获得更高的CHF值。     

APTES改性ZIF-L/PEBA混合基质膜强化渗透汽化分离苯酚研究

渗透汽化(PV)膜分离是一种高效节能、无污染的化工分离技术,在有机废水处理领域的应用潜力巨大。以3-氨丙基三乙氧基硅烷(APTES)改性二维ZIF-L(AZLs),将其引入聚醚嵌段酰胺(PEBA)内制备AZLs/PEBA混合基质膜,用于分离水溶液中的苯酚。系统表征了所制膜的微结构与物化特性,考察了APTES添加量、AZLs填充量、操作温度、料液浓度等对膜分离性能的影响。结果表明：AZLs均匀分散在PEBA基质中,表明两者具有良好的界面相容性。AZLs的加入使得膜疏水性增强而表面自由能降低,从而提高了PEBA膜的选择性。当分离80℃、1000 mg/kg苯酚水溶液时,AZLs/PEBA膜总通量可达2046 g/(m²·h),分离因子为25.4,并且具有一定的稳定性。所制AZLs/PEBA混合基质膜在含酚废水处理方面具有应用前景。     

渗透汽化-隔壁塔精馏耦合初步分离费托合成水的过程研究

费托合成水中含有醇、酮、酸等多种高附加值含氧有机物可提取出来作为高附加值产品,但由于费托合成水处量大,共沸体系复杂,通常需要首先对其进行初步分离。设计了直接两塔精馏、渗透汽化-两塔精馏、直接隔壁塔精馏、渗透汽化-隔壁塔精馏四种可供选择的初步分离工艺。根据渗透汽化实验数据在Aspen Plus中构建渗透汽化过程模型并进行模拟,结合灵敏度分析得到精馏过程的最佳工艺参数和模拟结果,并对四种工艺的能耗和有效能损失进行对比。结果表明,渗透汽化-隔壁塔精馏工艺具有明显的节能优势,其能耗较直接两塔精馏可降低15.85%,有效能损失降低45.74%。经渗透汽化膜预浓缩后,溶液的浓度可进入隔壁塔的适宜分离浓度区间,以充分发挥隔壁塔优势。由于渗透汽化所需能量可由余热等低品位热源提供,在余热充足的煤化工领域中可显著降低有效能损失。对于该过程而言,当渗透汽化膜价格低于438元/m²时,渗透汽化-隔壁塔精馏耦合工艺将会表现出较高的经济性。     

三相结构离子交换膜的构筑及应用研究

三相结构离子交换膜是一类具有惰性相、离子交换基团相和辅助功能基团相的特殊结构材料。传统两相结构离子交换膜受限于离子通量和选择性的相互制约,难以实现两者同步提升。因此,研究者开始关注新型三相结构,以改善离子传质路径。综述了离子交换膜从两相结构到三相结构的发展,介绍了微相分离离子交换膜、自具微孔离子交换膜、有机硅烷杂化离子交换膜和基于氧化石墨烯或金属有机框架的“三相”结构离子交换膜,讨论了离子膜介尺度中的相结构、孔道结构和缺陷等问题,并概述了三相结构在燃料电池、液流电池、一/二价离子分离和酸碱回收等领域所发挥的作用,以期给三相结构指导离子交换膜制备并提升性能提供策略参考。