TiO2溶胶杂化改性PPESK超滤膜的制备及性能

采用溶胶-凝胶法制备TiO2溶胶,优化了溶胶制备条件。采用相转化法制备了一系列TiO2含量的PPESK/TiO2有机-无机杂化超滤膜,并通过SEM,水接触角和超滤实验考察了TiO2含量对膜结构和性能的影响.结果表明,冰乙酸、去离子水和NMP用量分别为2,2,20mL时,溶胶胶凝时间为42.5h,利于杂化膜的制备.TiO2溶胶的加入,抑制了亚层指状孔的发展,利于海绵状孔的生成.膜的孔隙率、亲水性和抗污染性得到了明显改善.当TiO2质量分数为0.4%时,膜的纯水通量由310L/(m2·h)提高到427L/(m2·h),清洗后,膜通量恢复率为95.2%.但加入过量的TiO2溶胶时,纳米粒子的团聚使得杂化膜的各项性能下降.PPESK/TiO2杂化膜更适于高温凝结水的回用处理,处理效率高.     

PVA-PEG/SiO_2-TiO_2杂化纤维的制备与表征

以聚乙烯醇(PVA)与聚乙二醇(PEG)共混,并以正硅酸乙(酯TEOS)和钛酸四丁酯(TBT)为无机前驱体,采用溶胶-凝胶法制备了不同(SiO_2-TiO_2)含量的PVA-PEG/SiO_2-TiO_2杂化溶胶,陈化后用提拉法制得杂化纤维.研究了杂化溶胶的可纺性,并使用IR、光学显微镜、UV-Vis和TG对杂化纤维的结构与性能进行了研究.结果表明:随硅钛摩尔比的增加或随有机相中PEG/PVA质量比的增加,溶胶的可纺性变好;有机相与无机相之间通过化学键连接;纤维直径为50μm左右;TiO_2的引入增加了其抗紫外性,杂化纤维的耐热性优于纯PVA-PEG.     

借助硅气凝胶改善和调控聚丙烯腈热交联膜孔结构及性能

以正硅酸乙酯(TEOS)为前驱体,采用溶胶-凝胶法制备硅溶胶并将其引入聚丙烯腈超滤膜孔道中,经过热交联制得具有丰富海绵状孔结构的TPAN/SiO_2(TPS)杂化膜,考察了TEOS浓度对TPS杂化膜的孔结构和渗透性能的影响.结果表明,TPS杂化膜孔内引入的硅气凝胶限制了膜孔道结构在热交联过程的融并;随着TEOS浓度的增加,TPS杂化膜的平均有效孔径增加,水通量提高,所制备的杂化膜的BSA截留率都在98%以上;同时,杂化膜表现出优异的热稳定性和良好的耐溶剂性.     

SiO2/胶原水解物-聚乙烯醇杂化复合膜的制备与性能

以正硅酸乙酯(TEOS)为前驱体,采用溶胶-凝胶法原位制备了SiO2/胶原水解物-聚乙烯醇杂化复合膜(SiO2/CH-PVA杂化膜).通过溶胀、热重(TG)、红外光谱(FTIR)、扫描电镜(SEM)和拉伸实验,考察了SiO2对杂化膜性能的影响.结果表明,SiO2的引入减小了膜的平衡溶胀度,减缓了膜的溶胀速率,有效地抑制...     

硅系有机-无机杂化气体分离膜研究进展

硅系有机-无机杂化气体分离膜集取了有机相和无机硅相的优异性能,成为当前气体分离膜领域研究的焦点。概述了硅系杂化膜的发展现状,系统阐述了采用溶胶-凝胶法制备硅系有机-无机杂化膜,讨论了影响硅系杂化膜分离性能的主要影响因素,阐述了硅系有机-无机杂化膜的气体传递机理并展望了未来的发展方向。     

溶胶-凝胶法载银SiO2杂化膜的制备及性能研究

采用溶胶-凝胶法,在甲基化改性的SiO2溶胶中掺杂硝酸银,制备Ag/M-SiO2杂化膜。通过XRD、XPS、紫外-可见吸收谱、N2吸附-脱附以及气体渗透性能测试等方法,考察了银掺杂对杂化膜结构和性能的影响。结果表明,Ag/M-SiO2膜中的银元素完全为纳米金属银,具有面心立方结构。金属银的掺杂对Ag/M-SiO2膜的化学结构基本没有影响,但使其孔径和总孔体积略微增大。与未载银的SiO2膜相比,Ag/M-SiO2膜具有更大的H2渗透速率和更好的H2/CO2选择性。金属银的引入增强了H2的表面扩散作用,促进了H2在膜中的传递,提高了SiO2膜的水汽稳定性。     

原位聚合法制备聚酰亚胺／纳米二氧化硅杂化膜

溶胶-凝胶法是目前广泛被采用的制备聚酰亚胺／2氧化硅杂化膜的方法,此法通常是由PI的前驱体（如聚酰胺酸）和经水解缩合而成的二氧化硅溶胶制得。该方法制备的杂化膜普遍存在二氧化硅粒径较大且由于水的参与造成前驱体的稳定性偏低等缺点。本文以工业硅溶胶为硅源,首先制备了无水二氧化硅N,N-二甲基乙酰胺（DMAC）分散液,再以均苯四甲酸二酐（PMDA）、4,4,-二氨基二苯醚（0DA）为原料,采用原位聚合法制备了聚酰亚胺／纳米二氧化硅杂化膜,此方法克服了溶胶-凝胶法的缺点。利用FT-IR、SEM等手段对杂化膜的化学结构和形态进行了表征,证实杂化膜的热亚胺化较为完全,SiO2粒子以纳米尺度均匀地分布于聚酰亚胺基体中。动态力学分析表明随着二氧化硅含量的增加,杂化膜的Tg随之升高。另外,杂化膜的力学性能也有了很大改善。     

AZ91D镁合金表面无铬转化膜/杂化复合涂层的耐蚀性能

溶胶凝胶法制备的涂层性能优良,采用溶胶凝胶法、以正硅酸乙酯为主制备性能优良的涂层技术已很成熟,但用于镁合金的防护鲜有报道。为了提高AZ91D镁合金的耐蚀性能,先在其表面制备了无铬钼酸盐转化膜,然后采用有机/无机杂化溶胶凝胶的方法在转化膜表面制备杂化涂层,从而得到转化膜/杂化复合涂层。对复合涂层进行了红外光谱分析,并用扫描电镜(SEM)观察了其微观形貌,同时也对其进行了极化曲线和电化学阻抗谱分析。结果表明:二氧化硅和有机硅氧键通过溶胶凝胶反应,无机和有机间呈网络结构穿插在一起;复合涂层表面平整均匀,无开裂现象;转化膜层和转化膜/杂化复合涂层都可提高镁合金的耐蚀性,但后者的效果更加明显。     

聚酰亚胺/纳米SiO2杂化膜的制备和表征

以均苯四酸二酐、4,4＇-二氨基二苯基甲烷和正硅酸乙酯为原料,采用溶胶-凝胶法制备聚酰亚胺／纳米SiO2杂化膜,利用FT—IR、XPS、AFM对杂化膜的制备过程及杂化膜的结构进行了表征．证实聚酰胺酸加热亚胺化较为完全,杂化膜中有SiO2粒子生成,并以纳米尺度均匀地分布于聚酰亚胺中．采用综合热分析仪对杂化膜的热性能进行了分析,结果表明杂化膜的热性能优于聚酰亚胺膜,其热分解温度比聚酰亚胺膜提高了17．8℃．     

丙烯酸树脂/TiO2有机-无机杂化材料的力学、热学和光学性能研究

采用溶胶-凝胶法成功制备了均匀透明的丙烯酸树脂/TiO2有机-无机杂化材料.通过动态力学分析仪(DMA)、电子拉力机(Instron Tester)、热失重分析仪(TGA)和紫外可见光谱(UV-VIS)等手段表征了杂化材料的力学、热学和光学性能.结果发现丙烯酸树脂与TiO2杂化后,聚合物的力学性能、热稳定性和紫外屏蔽性能均有显著提高.与原位聚合法相比,共混法合成该杂化材料可获得更优异的力学性能.增加丙烯酸树脂中的丙烯酸含量能显著降低相分离,从而使其各种性能,特别是力学性能得以提高.     

前驱体水解聚合法制备聚偏氟乙烯-硅杂化膜 (Ⅱ)膜性能变化的原因分析

利用前驱体水解聚合法制备的杂化膜的力学性能有较大提高,膜的透过和截留性能亦有较大改变,采用红外、DSC、TG和电镜等手段分析引起聚偏氟乙烯(PVDF)-硅杂化膜性能变化的原因,实验用的前躯体为正硅酸乙酯(TEOS).TEOS加入到PVDF铸膜液中以后,杂化后膜的热分解温度上升了20℃,膜断面结构由指状向海绵状变化,这些都有利于膜机械性能的改善.但TEOS对PVDF的结晶度影响很小,PVDF的β晶形有所减弱.同时由于膜液中TEOS的存在,导致膜表面孔增大,膜的截留性能持续降低.     

Synthesis of polyetherimide/silica hybrid membranes by the sol–gel process: influence of the reaction conditions on the membrane properties

Hybrid polyetherimide (PEI)–silica membranes were synthesized. The aim was to obtain improved materials for gas separation media. The inorganic material was prepared via the sol–gel method through the hydrolysis of tetraethoxysilane (TEOS). The influence of the reaction conditions on the final membrane morphology and properties were studied. Scanning electron microscopy (SEM), energy-dispersive X-ray analysis (SEM–EDX), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the PEI and PEI–silica composite membranes. The evolution of TEOS hydrolysis and the condensation processes were verified by FTIR studies. The silica–polymer interaction was also analyzed. The SEM micrographs showed how the membranes distinct morphologies depended upon synthesis parameters and preparation techniques (presence of coupling agent, TEOS polymerization in situ or not, silica content and membranes redissolution). The permeation rates of CO₂, CH₄, O₂, N₂, and H₂ through the pure polymer and hybrid membranes were measured and showed an increase of gas permeability for hybrid membranes but, the CO₂/CH₄ and O₂/N₂ selectivities decreased compared to PEI membranes.     

静电纺丝法制备PVA/TEOS复合纤维膜的研究

以聚乙烯醇(PVA)和正硅酸乙酯(TEOS)为原料,通过静电纺丝技术与溶胶-凝胶(Sol-Gel)方法,制备出不同反应时间的PVA/TEOS复合纤维膜。FT-IR和TEM观察表明,PVA纤维与TEOS溶胶之间形成了化学键结合,PVA复合纤维膜中的空隙被SiO2填充。XRD表明复合反应使PVA结晶能力明显降低。TG表明,复合膜具有良好的耐热性能,且随着复合时间的增加逐渐提高。力学性能测试表明,复合膜的拉伸强度在复合时间为7 h时达到最大值59.15 MPa。吸水和保水性能测试发现,随着复合时间的增加,复合膜的吸水性先增大后减小,而保水性越来越高。     

PVA/TEOS/APTEOS杂化膜的渗透蒸发性能

采用溶胶-凝胶(sol-gel)法由聚乙烯醇(PVA)与正硅酸乙酯(TEOS)制备杂化膜。当TEOS质量分数大于15%时,杂化溶胶液开始浑浊,呈现出一定的相分离。退火温度升高,杂化膜的溶胀度和渗透通量下降,分离因子提高。料液温度升高,膜的溶胀度和渗透通量增大,而分离因子下降。加入偶联剂γ-氨丙基三乙氧基硅氧烷(APTEOS)改善了有机相与无机相的相容性,抑制了杂化膜的相分离。TEOS与PVA中的羟基发生交联反应形成共价键Si-O-C,使得PVA中羟基减少,降低了PVA膜的结晶度。     

Synthesis and properties of chitosan/SiO2 hybrid materials

This study primarily aims to explore the strength and thermal properties of various hybrid materials that are made of tetraethoxysilane/vinyltriethoxysilane (TEOS/VTES) and chitosan in different weight ratios. It is confirmed, from micro Fourier transform infrared (micro FT-IR) and nuclear magnetic resonance (NMR) analysis, that hydrogen bonds emerge between chitosan and SiO₂ in hybrid materials. With the addition of more VTES and TEOS, the surface of the hybrid material features thick granules. In addition, the mechanical performance and thermostability of both types of hybrid are better than pure chitosan. The former is enhanced with an increasing amount of TEOS until it exceeds 2.4 g and the latter is also improved with an increasing amount of TEOS.     

电化学诱导表面引发原子转移自由基聚合构筑离子型聚醚砜膜功能表面

采用电化学诱导表面引发原子转移自由基聚合(SI-eATRP)技术,在涂覆聚多巴胺的聚醚砜膜基底上接枝离子型聚合物分子刷聚对苯乙烯磺酸钠,并通过单体浓度对聚合物分子刷进行调控。采用SEM、AFM、XPS、水接触角等表征方法对改性聚醚砜膜的结构和性能进行表征;采用水通量对其进行滤过性能测定。结果表明:成功地在改性聚醚砜膜表面接枝离子型聚合物分子刷聚对苯乙烯磺酸钠;聚合物刷相互缠结形成了球状颗粒;随着电化学诱导体系中单体浓度的增大,聚合物分子刷的接枝量增加,同时水接触角显著降低;聚合物膜表面离子型分子刷的构筑改善了亲水性,因此其纯水通量明显增加,牛血清白蛋白(BSA)截留率和通量恢复率都得到了提高。SI-eATRP用于聚合物膜材料的表面改性和调控,在生物相容性膜等领域具有潜在的应用前景。     

Characteristics of organic-inorganic hybrid plasma polymer thin films for low-κ ILD applications

This study investigated the effects of plasma power and tetraethylorthosilane (TEOS) to cyclohexene ratios on low-κ organic-inorganic hybrid plasma polymer thin films deposited on silicon (100) substrates. These films were deposited using a plasma enhanced chemical vapor deposition (PECVD) method, in addition to the electrical and mechanical properties of the resulting composites. Cyclohexene and TEOS were used as organic and inorganic precursors, respectively, with hydrogen and argon as precursor bubbler gases. Furthermore, additional argon was used as a carrier gas. The as-grown polymerized thin films were analyzed using ellipsometry, Fourier-transform infrared (FT-IR) spectroscopy, atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The ellipsometry results showed the thickness of the hybrid thin film, and the FT-IR spectra showed that the hybrid polymer thin films were completely fragmented and polymerized between cyclohexene and TEOS. AFM results showed that polymer films with a smooth surface could be grown under various deposition conditions, while TEM and XRD showed that the hybrid thin film was an amorphous plasma polymer thin film without porosity. In addition, current-voltage (C-V) curves were prepared to calculate the dielectric constants. Post-annealing was applied to investigate the thermal stability of hybrid plasma polymer thin films in the hardness, Young's modulus, thermal shrinkage, and the dielectric constant at 400 °C.     

热致相分离法-溶胶凝胶工艺制备丙烯腈-丙烯酸甲酯共聚物微孔膜

以投料摩尔比为80/20的可熔融丙烯腈-丙烯酸甲酯共聚物(80/20AN-MA)为基体,良溶剂碳酸乙烯酯(EC)和绿色环保的非溶剂三甘醇二乙酸酯(TEGDA)为复配稀释剂,正硅酸乙酯(TEOS)为添加剂,热致相分离法(TIPS)溶胶凝胶工艺制备含有纳米二氧化硅(SiO2)的AN-MA杂化微孔膜。研究了复配稀释剂的配比、共聚物浓度以及添加剂的加入量对微孔膜的结构、孔隙率、亲水性、渗透性和力学性能的影响。结果表明,TIPS法结合溶胶凝胶工艺成功制备了SiO2纳米粒子均匀分布的AN-MA微孔膜。当共聚物质量分数为9%,复配稀释剂中EC与TEGDA的质量比为6/4,TEOS质量分数为5%,凝固浴为25℃水浴时,微孔膜的纯水通量提高了50%,达到120.0L/(m2·h),断裂强度提高了17%,达到3.4 MPa,膜的亲水性也得到了一定提高。     

Production of porous poly(ε-caprolactone)/silica hybrid membranes with patterned surface pores

This paper reports a novel way of synthesizing porous poly(ε-caprolactone) (PCL)/silica hybrid membranes with a patterned surface pores by casting a mixture containing a PCL solution and sol-gel derived silica sol at room temperature. When the initial TEOS content in relation to the PCL content in the mixture was ≥ 20 vol.%, a highly porous structure containing patterned surface pores, ~ 40-70 μm in size, was formed successfully. The silica phase was hybridized uniformly with the PCL polymer without any noticeable phase separation, as confirmed by energy dispersive X-ray spectroscopy (EDS). The porosity increased from 4.5 to 39.2 vol.% with increasing initial TEOS content from 0 to 40 vol.%. However, the hybrid membranes prepared at an initial TEOS content of ≥ 20 vol.% showed a reasonably high tensile strength and elastic modulus, ranging from 7.6 to 5.0 MPa and 79 to 51 MPa, respectively.     

Interfacial interactions and their influence to phase behavior in poly(vinyl pyrrolidone)/silica hybrid materials prepared by sol–gel process

In this research, hybrid materials constructed by poly(vinyl pyrrolidone) (PVP) and inorganic tetraethyloxysilane (TEOS) or methyltriethyloxyslane (MTEOS) were synthesized via sol–gel process. From visual and scanning electron microscopic (SEM) observation, inorganic silicate was not separated from the organic phase in PVP/MTEOS hybrid system and in PVP/TEOS hybrid system with 20 wt.% or less TEOS content. With 40 wt.% TEOS content, microphase separation occurred; furthermore, phase separation and phase inversion can be observed with TEOS content increased to 60 wt.% or more in PVP/TEOS hybrid system. These results were confirmed by the variation of glass transition behavior. From infrared spectra analysis, hydrogen bonds were formed in both PVP/MTEOS and PVP/TEOS hybrid systems. However, higher hydrogen bonding interaction in PVP/TEOS did not induce higher compatibility as compared to PVP/MTEOS. This was due to the greater non-polar interaction between methyl group of MTEOS and polymer backbone in PVP/MTEOS hybrid system.