可食性大豆分离蛋白/改性纤维素共混膜的性能

研究了不同质量百分数的甲基纤维素(MC),羟丙基纤维素(HPC),羟丙基甲基纤维素(HPMC)对大豆分离蛋白(SPI)膜性能的影响。结果表明,改性纤维素的基团类型和添加质量百分数均对SPI膜的性能产生显著影响。在SPI膜中添加MC、HPC和HPMC后,膜的透光率持续降低;但膜的拉伸强度明显增加,且添加相同质量百分数的HPC、MC、HPMC对膜拉伸强度的增强依次增加;膜的表面疏水性持续增大,增大的幅度依次为MCHPMCHPC。特别在添加MC后,在膜的拉伸强度增强的同时,膜的伸长率也提高。这表明改性纤维素中不同的基团决定了纤维素分子链间及其与SPI分子链间的相互作用,从而改变了SPI分子链间的相互作用。     

增强微孔二氧化硅氢气分离膜疏水性的研究现状

综述了提高微孔二氧化硅膜疏水性的方法以及微孔二氧化硅膜材料在氢气分离方面的应用.孔表面羟基是导致微孔二氧化硅膜亲水的主要原因,因此在溶胶-凝胶反应阶段用疏水基团来修饰溶胶,可以在最终材料的孔表面引入疏水基团,降低羟基浓度,从而提高其疏水性.修饰后的二氧化硅膜孔结构没有显著的变化,可以应用于氢气分离等领域.     

黏度法研究非离子型高分子对盐水溶液中油酸钾聚集行为的影响

测定了在不同浓度聚丙二醇(PPG)、聚乙二醇(PEG)和聚乙烯基吡咯烷酮(PVP)存在条件下油酸钾盐水溶液的黏度,研究了非离子型高分子对盐水溶液中油酸钾表面活性剂聚集行为的影响,结果表明,随着非离子型高分子的加入,油酸钾盐水溶液的黏度迅速下降,但是程度显著不同,不仅如此,加入更加疏水的聚丙二醇以后,油酸钾盐水溶液黏度下降的程度最低。由此可见,非离子型高分子疏水程度不是导致表面活性剂盐水溶液黏度下降的唯一因素,高分子与表面活性剂疏水和亲水基团之间的相互作用,以及由此形成的高分子/表面活性剂聚集体的形态,是决定表面活性剂盐水溶液黏度下降最主要的原因。     

大豆分离蛋白可食膜的制备及微波处理对性能的影响

制备了大豆分离蛋白可食性膜.为了提高大豆分离蛋白膜的性能,通过微波进行处理,考察微波对蛋白膜性能影响.结果表明:由于微波处理作用,蛋白膜机械性能增加显著,蛋白膜的阻水性能也得到提高.通过溶胀实验进一步考察蛋白膜交联程度,结果表明:微波处理大豆分离蛋白可食性膜,交联程度提高.     

离子型表面活性剂与疏水缔合聚丙烯酰胺的相互作用

通过动态流变、幂律模型、动/静态激光光散射以及荧光光谱考察了丙烯酸十八酯(ODA)、丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)经超声辅助(Ultrasonic assist)自由基共聚制得的疏水缔合聚丙烯酰胺(UHAPAM)的动态流变性及其与阴阳离子型表面活性剂(十二烷基硫酸钠(SDS)和十六烷基三甲基溴化铵(CTAB))之间相互作用关系。结果表明,这种假塑性流体的临界聚集浓度(CAC)为0.27%。当UHAPAM水溶液浓度高于CAC时,SDS影响分子间疏水缔合,使水溶液表观粘度下降;CTAB反而改善疏水缔合性,使表观粘度明显增加,但增粘效果越来越缓和。表面活性剂均使溶液触变性降低。同时,形状因子(〈Rg〉/〈Rh〉)在SDS-UHAPAM体系里随SDS浓度的增加而增加,聚合物分子线团变得相对舒展;而在CTAB-UHAPAM体系里则随CTAB浓度增加而出现最低值,聚合物分子链段历经一个卷缩然后舒展的过程。在SDS和CTAB胶束中加入UHA-PAM,SDS聚集数先减小后增大,而CTAB聚集数则持续增加。     

表面活性剂结构对纳米CeO2在水中的分散性影响

采用悬浮液体系吸光度法,研究不同结构表面活性剂对纳米CeO2粉体在水中分散性影响。考察了影响分散稳定性的物理分散方式、表面活性剂的结构和浓度等因素。结果表明,超声波分散效率远优于机械搅拌。表面活性剂作为纳米CeO2在水介质中的分散剂,其分散性与表面活性剂结构有重要关系。非离子型表面活性剂效果优于离子型表面活性剂。非离子型表面活性剂以亲油基团朝向CeO2粒子,且亲油基团链长较长的效果更好;而离子型表面活性剂以亲水基团朝向CeO2粒子,亲水基团小的表面活性剂效果好,亲油基团的链长度影响不太明显。     

浸渍法在聚丙烯基体上负载二氧化钛薄膜

采用TiO2浆料浸渍法在聚丙烯塑料上负载纳米二氧化钛薄膜.研究了不同表面处理方法、表面处理条件和浆料固相含量对TiO2薄膜的形成和结构的影响.用扫描电镜观察了TiO2薄膜的表面形态,用傅立叶变换红外光谱仪和X射线光电子能谱分析了表面处理后聚丙烯表面所带基团、原子及化学态.研究表明,经过离子溅射表面镀Ti膜处理和表面磺化处理后,可改善聚丙烯表面与TiO2粒子间的亲和度,以镀Ti膜的表面形成的TiO2薄膜结构较均匀致密.表面磺化处理存在最佳时间,时间过长,会使表面产生点蚀,影响成膜质量.最佳处理时间与磺化速率有关.浆料中TiO2含量越高,浆料粘度越大,膜越容易开裂和脱落,较低粘度的浆料可获得结构较均匀的膜.     

丝素膜表面磺酸化研究

从蚕丝中提取丝素蛋白制备成纯丝素膜及PEGO丝素膜,首次采用硫酸处理,在丝素膜材料表面引入了磺酸基团;采用电子能谱和全反射红外光谱分析材料的表面性质,表明硫酸处理丝素膜,可以使PEGO丝素膜表面带上磺酸基团,以共价键的结合方式牢固地固定在表面.这将大大提高丝素膜的抗凝血性,防止细胞在丝素膜上的粘附.X射线衍射表明,丝素膜在硫酸处理后,其结晶度增加,特别是silk Ⅰ的结晶,但是,经硫酸处理后,丝素膜的断裂伸长率与强度有所下降.     

成膜基质对炭膜结构与气体分离性能的影响

以间苯二酚-甲醛为碳源,F127为添加剂,经成膜与炭化得到炭膜.通过热失重分析、红外光谱、元素分析及透射电镜从微观上分析了前驱体的热解过程及碳结构演变.采用X射线衍射及氮气吸附技术分别测定了炭膜碳结构与孔结构.研究了成膜基质表面疏水性对成膜过程的收缩率、碳结构、孔结构及气体分离性能的影响.结果显示,成膜基质对炭膜微观结构与分离性能影响显著.疏水性较大的玻璃比聚四氟乙烯与不锈钢更有助于减小成膜过程中径向收缩率,并得到高比表面积与孔体积的炭膜,其对O2/N2选择性高达10以上.     

负压膜蒸馏中不同类型表面活性剂的润湿机理研究

表面活性剂导致的膜润湿是膜蒸馏技术在处理实际废水面临的主要问题.为了缓解膜润湿现象,采用新型的负压膜蒸馏来评价不同类型表面活性剂盐溶液的润湿能力,并利用扫描电子显微镜、动态光散射等手段分析了表面活性剂的润湿和污染机理.首先,恒浓处理0.1 mmol/L SDS、CTAB以及Tween-20盐溶液,当料液含阴离子表面活性剂(SDS)时,膜通量稳定,冷凝液电导率保持在3μS/cm以内.而料液含阳离子(CTAB)和非离子表面活性剂(Tween-20)时,膜通量都衰减,甚至出现负值.通过分析污染膜表面以及溶液中表面活性剂胶束的粒径,证实CTAB和Tween-20是通过胶束污染膜表面,造成膜润湿.为了探究胶束污染和表面活性剂浓度之间的关系,分别测试表面活性剂浓度为0.1CMC、0.5CMC、1.0CMC的盐溶液,其中SDS、CTAB以及Tween-20的临界胶束浓度(CMC)分别为9.6×10^-3 mol/L、9.1×10^-5 mol/L和6×10^-5 mol/L.当分别处理9.1×10^-6 mol/LCTA...     

大豆分离蛋白膜制备及改性研究的现状和应用

目的整理和归纳目前国内外关于大豆分离蛋白(Soy Protein Isolate,SPI)膜的制备方法及改性研究的最新研究成果,为将来制备高性能的该系列材料提供依据。方法归纳整理国内外文献,从文献中归纳SPI膜的基本性能和目前SPI膜的3种主流制备方法,并从力学性能、防潮性能、抑菌性能、阻氧阻湿性能等4个方面介绍SPI膜的改性研究现状,最后对SPI膜的应用情况进行归纳。结果 SPI具有来源广泛、价格低廉、环境友好等诸多优点。在对其进行改性后,由SPI制备薄膜的成膜性能、力学性能、防潮性能、抑菌性能、阻氧阻湿性能均有显著提高。结论对SPI膜进行有效改性后,其在保鲜包装、环保包装、可食用包装、风味食品包装等领域具有广泛且良好的发展前景。     

Aligned ramie fiber reinforced arylated soy protein composites with improved properties

To enhance the strength, ramie fibers aligned in vertical (V), horizontal (H) as well as both vertical and horizontal (X) directions were used to reinforce soy protein materials (SC), coded as VSC, HSC and XSC. The soy protein isolate was arylated with 2,2-diphenyl-2-hydroxyethanoic acid through the process of “dip-coating”, coded as SC-B. The SC and SC-B composite films were characterized by Fourier transform infrared spectra, scanning electron microscopy, thermogravimetric analysis, dynamic mechanical thermal analysis, and tensile testing. Substantial improvement in the water uptake (from 100% to 25%) and the increased modulus (from 125 to 942 MPa) of the VSC-B composite were observed. This could be attributed to the formation of phase separation induced hydrophobic microparticles of DPHM on the surface of the SC-B films upon arylation, leading to the hydrophobicity. The thermal stability of the arylated composites increased compared to non-arylated ones. The VSC-B materials exhibited the highest water resistance and mechanical properties compared to HSC-B and XSC-B. Therefore, the arylation of SPI and alignment of the ramie fibers in the composites played an important role in the improvement of mechanical properties. This work provided a novel idea to improve the water resistance and modulus by reinforcing the protein matrix with natural fibers.     

Physicochemical properties of soy protein isolate/carboxymethyl cellulose blend films crosslinked by Maillard reactions: Color, transparency and heat-sealing ability

Soy protein isolate (SPI) films have many potential applications in the biomaterial field as surgical dressings for burns, films for reduction of wound inflammation, and facial masks. The appearance and the sealing ability are important physicochemical properties that greatly influence consumer acceptance of such protein-based films. The aim of the present work was to investigate the chemical structure and the physical properties associated with color, transparency and heat-sealing ability for SPI/carboxymethyl cellulose (CMC) blend films prepared by solution casting, with weight proportions 90/10, 80/20, 70/30 and 60/40. Fourier transform infra-red (FTIR) and solid-state ¹³C nuclear magnetic resonance (NMR) spectra confirmed that Maillard reactions occurred between SPI and CMC. The Hunter color value (L, a, b) and transparency of films were affected by varying the proportions of SPI and CMC. With increasing degree of crosslinking of SPI and CMC, the yellow color of the films was diluted and transparency was improved. Peel strength and tensile strength measurements showed that the Maillard reactions had the main effect of enhancing the heat-sealing ability above the melting temperature. These results indicated that the structure and properties of SPI-based films could be modified and improved by blending with CMC.     

壳聚糖／大豆分离蛋白复合包装膜的制备与表征

采用壳聚糖(CS)和大豆分离蛋白(SPI)为基材,制备了可降解包装膜。用红外光谱、X射线衍射和扫描电镜对复合包装膜结构进行表征。对复合包装膜的拉伸性能和透光性能进行了测试和分析。结果表明:CS和SPI之间存在一定的相互作用;当SPI质量分数为10%时,复合包装膜的拉伸性能优于纯壳聚糖膜,透光性较纯壳聚糖膜略有下降。     

大豆分离蛋白与明胶蛋白复合膜的制备与性能研究

以大豆分离蛋白为基质,添加明胶蛋白,用溶液铸膜法制备复合膜.研究了成膜液的溶液性能;复合膜的各种性能,包括表观性能、力学性能、阻隔性能.通过扫描电子显微镜观察了膜的微观结构.结果表明,当明胶含量为30%(质量分数)左右,两种蛋白的相容性最佳,复合膜的各项性能达到较佳值,拉伸强度达到31.59MPa,断裂伸长率达到65.96%,并且对氧气和水都有良好的阻隔性.     

Incorporation of modified soy protein isolate as filier in BR/SBR blends

The surface modification of soy protein isolate (SPI) and the use of modified SPI as reinforcing filler replaced carbon black in BR/SBR composites were studied. The effects of coupling agents γ-aminopropyltriethoxysilane (KH-550), γ-methacryloxypropyltrimethoxysilane (KH-570), bis-(γ-triethoxysilylpropyl)-tetrasulfide (Si-69), isopropyl tri-(dioctylpyrophosphate) titanate (NDZ-201) on the physical and mechanical properties of the composites were also investigated. Modified SPI was analyzed by Infrared spectra, scanning electron microscopy, and X-ray diffraction. The results showed that the optimal reaction conditions were determined, that is, the optimal reactions were 4 g SPI, 50% Glycidyl methacrylate (by SPI weight), 3 h of reaction time and 80 °C reaction temperature. Through the physical and mechanical properties of composite, the results showed that when a small number of modified SPI (3–5 phr) as reinforcement agent was used, the mechanical properties were improved. KH-550 had good effect on enhancing the overall properties of the composites.     

Bioadhesive Design Toward Renewable Composites: Adhesive Distribution and Molecular Adhesion

Improvements in renewable compositions of adhesives are key for advancing the existing wood industry and developing biocomposites. Building upon prior studies on fundamental interactions between model compounds of fiber and bioadhesives, more complex bioadhesives are investigated. Cold denaturation of soy protein isolate (SPI) in dilute sodium hydroxide provide sufficient physical strength for wood composites. Due to swelling, 5% epoxy resin is added to the SPI adhesive resulting in improved physical strength and water resistance. The SPI and epoxy are evenly distributed on the fiber surface, while additional SPI fills the gaps between fibers based on fluorescence microscopy and X-ray photoelectron spectroscopy. Molecular dynamics (MD) simulations show that the physical strength of the composites increases with the content of SPI, with the number of hydrogen bonds (H-bonds) as primary driver; in MD simulations, the composite strength is highest at 3% epoxy, though higher epoxy doses results in more H-bonds. In ReaxFF MD simulations, other contributions (e.g., van der Waals energy) show no correlation. The developed bioadhesive and the interaction mechanism demonstrate here emphasize the weak physical interactions in these materials, though covalent bonds and other larger scale phenomena are important as well for macro performances of the bioadhesives.     

Preparation and characterization of silica/fluorinated acrylate copolymers hybrid films and the investigation of their icephobicity

Inexpensive hydrophobic and icephobic coatings and films were obtained by a simple method. These coatings were prepared by mixing silica sol and fluorinated acrylate copolymers. There was a phase separation process in the film-forming which can provide the excellent performance. Small amount (about 2 wt.%) of fluorinated (methyl) acrylate was used in all of these coatings. The coatings were eco-friendly by using ethanol as the solvent system. Scanning electron microscopy, atomic force microscope, energy dispersive X-ray fluorescence spectrometer, water contact angle, thermal gravimetric analysis and tests of adhesion and hardness had been performed to characterize the morphological feature, chemical composition, hydrophobicity and icephobicity of the surface, thermal stability and mechanical properties of the coatings. The results showed that the films had good hydrophobicity, high thermal stability and excellent mechanical properties of adhesion strength and pencil hardness. Furthermore, by testing their properties of delaying water droplet from icing, it was found that ice formation was delayed for 90 min compared with the glass surface at − 5.6 °C. The hybrid coatings may be suitable for large-scale and practical application owing to its flexibility and simplicity.     

大豆蛋白添加量与成膜环境对大豆分离蛋白膜的影响

以大豆分离蛋白(SPI)为原料,通过调整SPI和甘油(GLY)的比例来制备不同配方的可食性SPI包装膜。通过观察薄膜色泽、柔软性等表观情况,测定其机械性能(抗拉强度和断裂伸长率)和阻隔性能(阻湿性和阻氧性),并比较了其性能。结果表明:影响SPI膜性能的主要因素为SPI添加量、SPI与增塑剂的质量比、干燥条件;在pH=9条件下,SPI质量为5.66 g,SPI与GLY质量比为6∶1.5,以自然晾干和烘箱干燥结合法进行干燥时,膜的性能最优。