Hydrophilic property of SiO_2-TiO_2 overlayer films and TiO_2/SiO_2 mixing films

The photo-induced hydrophilicity of SiO2 overlayer on TiO2 films prepared by sol-gel method was investigated by means of soak angle measurement, XPS, UV-VIS and FTIR spectra. The results show that, compared with the TiO2 film without SiO2 overlayer, when the TiO2 film is thoroughly covered by SiO2 overlayer, the hydrophilicity and the sustained effect are enhanced. It is found that the significant growth of the OH- group occurs in the surface of SiO2 overlayer. The different mechanism of enhanced hydrophilicity between SiO2 overlayer on TiO2 films and TiO2/SiO2 mixing films was analyzed. The result suggests that the photo-generated electrons created in the interface between TiO2 and SiO2 tend to reduce the Ti（Ⅳ） cation to the Ti（Ⅲ） state, and the photogenerated holes transmit through the SiO2 layer to uppermost surface efficiently. Once the holes go up to the surface, they tend to make the surface hydrophilic. The stable hydrophilicity of SiO2 overlayer which adsorbs more stable OH groups, enhances the sustained effect, i.e. the super-hydrophilic state can be maintained for a long time in dark place.

A Structure-properties Study of MDI-based Hydrophilic Polyether-polyester Polyurethane

A series of segmented polyether-polyester polyurethane with amorphous hydrophilic soft segment domains were prepared from 4,4'- diphenylmethane diisocyanate (MDI), polybutylene adipate (Glycol) 2000 (PBA2000), and polyethylene glycol 1000 (PEG1000), with 1,4-butanediol (BDO) as the chain extender. Furthermore, several representative properties of the polyurethanes, such as moisture permeability, water resistance, hydrophilic property, and phase inversion temperature, were investigated. The studies show that the structure and concentration of soft segment have a remarkable effect on the main application properties of polyurethane. On the contrary, the functional properties of the polyurethane are almost not affected by its hard segment.

Increase in the Hydrophilicity and Lewis Acid-Base Properties of Solid Surfaces Achieved by Electric Gliding Discharge in Humid Air: Effects on Bacterial Adherence

This study addressed the effects of treatment with gliding discharge plasma on the surface properties of solid materials, as well as the consequences concerning adherence of a model bacterium. As evaluated by contact angles with selected liquids, plasma treatment caused an increase in surface hydrophilicity and in the Lewis acid-base components of the surface energy of all materials tested. These modifications were more marked for low density polyethylene and stainless steel than for polytetrafiuoroethylene. After treatment, the hydrophilicity of the materials remained relatively stable for at least 20 days. Moreover, analysis of the topography of the materials by atomic force microscopy revealed that the roughness of both polymers was reduced by glidarc plasma treatment. As a result of all these modifications, solid substrates were activated towards micro-organisms and the adherence of S. epidermidis, a negatively charged Lewis-base and mildly hydrophilic strain selected as the model, was increased in almost all the cases tested.

Theoretical Study on Thermodynamic Properties and Hydrophilicity of Polychorinated Phenothiazines (PCPTZs)

The thermodynamic properties of 135 polychlorinated phenothiazines （PCPTZs） in the standard state are calculated using a combination of quantum mechanical computations performed with the Gaussian 03 program at the B3LYP/6-311G^＊＊ level, and their octanol-water partition coefficients （logKow） are calculated based on group contributions. The chlorine substitution pattern strongly influenced the thermodynamic properties and hydrophilicity of the compounds. The thermodynamic properties of congeners also depend on the chlorine substitution pattern. The effect of chlorine substitution pattern is quantitatively studied by considering the mmaber and position of Cl atom substitution （Npcs）. The results show that the Npcs model may be used to predict the thermodynamic properties and hydrophilicity for all 135 PCPTZ congeners.

Preparation and Hydrophilicity of Copolymerization of Chitosan Selectively Grafted by Polyethylene Glycol

Copolymerization of chitosan selectively grafted by polyethylene glycol was prepared. Chitosan was selectively grafted by monomethoxy polyethylene glycol（mPEG-OH）, which contained a hydroxyl group combining with hexamethylene diisocyanate（HDI） to form a novel macromonomer namely monomethoxy polyethylene glycol isocyanate（mPEG-NCO） containing a isocyanate group with higher chemical activity in ethyl glyoxalate solution absolutely without water. The selective grafted copolymerization of Chitosan with mPEG-NCO was conducted under heterogeneous conditions as suspension in dimethylformamide. The hydrophilic copolymers of chitosan were prepared by condensation reaction of isocyanate group on mPEG- NCO with hydroxy groups on chitosan chains because amino groups on chitosan chains were protected by complexion formation with copper ions. The effect of reaction condition on the grafting extents was discussed. Swelling properties of mPEG-g-CS were researched. The graft copolymer mPEG-g-CS was characterized by the infrared spectra. The experimental result showed that the copper ions were very effective to protect amino groups from condensation reaction. The swelling degree in water increases with adding of grafting ratio. The maximum swelling degree was up to above 132% when the grafting ratio was about 270%. The graft copolymer can be soluble partially in pure water.

Engineered Wood/Bamboo Laminated Composites for Outdoor Hydrophilic Platforms:Structural Design and Performance

Landscape designers increasingly prefer to use wood/bamboo-based composites for outdoor hydrophilic platforms owing to their natural surface texture,high performance,and sustainability to facilitate extensive interaction between people and water and enable the full range of ecological functions of water resources.In this study,four laminated composite(LC)structures were designed and manufactured using fluffed bamboo and wood veneers.Their surface textures,profile densities,water resistances,and mechanical properties were then evaluated.The type of fluffed veneer of the surface layer determined the texture of the LC surface.The specific structures of fluffed bamboo and wood veneer laminations were found to affect the LC profile density variability,water resistance,and mechanical properties owing to the differences in the strength and interfacial properties of bamboo and wood fibers.Finally,the water resistance and mechanical properties of all four LCs were found to be much higher than the highest level specified in GB/T 20241-2006 for“laminated veneer lumber”and GB/T 30364-2013 for“bamboo scrimber flooring”,indicating that they are promising materials for structures and flooring,particularly for outdoor hydrophilic platforms.

Hydrophilicity Modification of Addition-cured Room Temperature Vulcanization Silicone Rubber

丙烯基终止了氯化聚醚被用来改进 hydrophilicity 治好 ofaddition 的室温硫化硅橡胶。与增加 thepolyether，橡皮吸收的 hydrophilicity 和水是 increased.Themechanical 性质被补充说 polyether.The 结果证明氯化聚醚的 1.5wt% 向硅腈橡胶提供了合适的 hydrophilicity 也改进。

光敏活性剂含量对PSPI薄膜性能的影响

为探究光敏活性剂对光敏聚酰亚胺(PSPI)薄膜性能的影响,以2,2-二(3-氨基-4-羟基苯基)六氟丙烷(6FAP)、5-氨基-2-(4-氨基苯基)苯并咪唑(BIA)和3,3′,4,4′-二苯酮四酸二酐(BTDA)为单体,合成聚酰亚胺低聚物,与聚乙二醇二丙烯酸酯(PEG400DA)、交联剂和光引发剂混合,涂膜光固化后得到PSPI薄膜,探究光敏活性剂PEG400DA含量对PSPI薄膜的热性能、亲水性能、力学性能、导电性能以及结构的影响。结果表明,制备出了含有聚酰亚胺特征峰的薄膜,随着PEG400DA含量增加,红外特征峰强度增强;PEG400DA质量分数为4%时,热稳定性最优,初始失重温度为343.12℃;随着PEG400DA含量增加,亲水性逐渐降低;拉伸强度会随着PEG400DA含量的增加而增大,但断裂伸长率在PEG400DA质量分数为6%时,达到最高值,为17.73%;随着电场强度的增大,PEG400DA含量越高,电导电流增大,当PEG400DA质量分数为8%时,导电性过强,失去使用价值。综合来看,光敏活性剂质量分数为6%时,PSPI薄膜的性能最优。

磺化热压PE无纺布的性能研究

利用磺化反应及热压处理,化学改性聚乙烯(PE)无纺布的亲水性和离子交换能力,讨论了时间、温度、热压压力等不同反应条件对材料力学性能的影响,使用显微镜(SEM)对磺化前后PE无纺布的外表状态进行观察,磺化后无纺布表面磺化效果有效提高.实验结果表明,PE无纺布的亲水性和离子交换水平在反应温度为85℃,热压压力为8 MPa,反应时间为2 h的磺化反应条件下,不仅PE无纺布的亲水性和离子交换能力得到了显著的改善,而且拉伸性能和耐腐蚀性能得到了较好保留.

Microstructure and Properties of PET Fabric Grafted by Polyacrylic Acid with Inverse Microemulsion Polymerization

Annual production output of poly(ethylene terephthalate)(PET) fiber has been over 15 million tons in China due to its good mechanical properties and processability,but the shortage of hydrophilic group of PET has imposed many limitations to further extend its application.The PET fabrics were grafted with polyacrylic acid in inverse microemulsion after low pressure plasma treatment,and the microstructure and properties of the grafted fabrics were investigated with infrared spectroscopy,scanning electron microscope(SEM),hydrophilic and mechanical tests.The grafting yield was increased with the grafting time.The grafting polymer was in the granular form with its particle size ranging from a few micrometers to a dozen of micrometers,normally smaller than the fiber diameter.The moisture regain and water uptake increased while the air permeability of the grafted fabrics decreased with the increase of grafting yield.The bending rigidity and tensile properties show slightly complicated behaviors with grafting yield.The inverse emulsion grafting technique can be used to control the grafting polymer architecture.

Variations in surface and electrical properties of polytetrafluoroethylene film after plasma-induced grafting of acrylic acid

Polytetrafluoroethylene(PTFE) film was graftpolymerized with acrylic acid(AAc) via a low-temperature plasma technique.The effect of plasma treatment parameters(radio-frequency power and treatment time) on the spin number of free radicals in PTFE film was examined.Attenuated total reflection Fourier transform infrared(ATR-FTIR)spectroscopy,X-ray photoelectron spectroscopy,scanning electron microscopy,and atomic force microscopy were employed to characterize the chemical structure,surface composition,and microstructure of the original PTFE and PTFE-g-PAAc films,respectively,in order to verify the successful graft polymerization of AAc onto a PTFE film surface.Thermogravimetric analysis illustrated that the thermal stability of bulk PTFE film remains unchanged after graft modification.Water contact angle measurements confirmed that the hydrophilicity of PTFE-g-PAAc film was effectively improved as compared to the original PTFE film.The dielectric constant(ε_r) of PTFE-g-PAAc(GD =218 μg/cm^2) film remained invariable,compared to that of the unmodified PTFE film.Nevertheless,the dielectric loss(tanδ) of PTFE film increased considerably,from 0.0002(GD = 0μg/cm^2) to 0.0073(GD = 218 μg/cm^2),which might be due to the increase in surface polarity and moisture resulting from AAc graft modification.In addition,the surface electrical resistance(R_s) of PTFE film decreased slightly,from 131.89(GD = 0 μg/cm^2) to 110.28 Ω cm^2(GD = 218μg/cm^2) after surface modification,but still retained its inherent high impedance.

Syntheses and Surface Properties of Polyacrylonitrile-based Copolymer Membranes Containing Sugar Moieties

To improve the hydrophilicity of polyacrylonitrile-based membranes, sugar moieties were incorporated into acrylonitrile-based copolymers via the radical copolymerization of α-allyl glucoside(AG) with acrylonitrile(AN) with 2,2′-azobis-iso-butyronitrile(AIBN) as the initiator in dimethyl sulphoxide(DMSO). It was found that the yield increased with the increase of the initiator concentration and reaction time, while it decreased with the increase of the monomer molar ratio of AG to AN. Raising the AG proportion in the monomer mixture resulted in the increase of the AG content in the copolymer. M_v of the copolymers decreased with increasing the AG monomer fraction in feed. The copolymers were fabricated into dense membranes and their surface properties were studied by means of the water contact angle measurement and platelet adhesion tests. It was found that the static water contact angle on the membrane decreased significantly from 70° to 33° with the increase of the AG content. The adhesive number of platelets on the membrane surface also decreased significantly with increasing AG content in the copolymers. These results demonstrate that the hydrophilicity and biocompatibility of the acrylonitrile-based copolymer membranes could be improved efficiently by the copolymerization of acrylonitrile with vinyl carbohydrates.

Fabrication and Properties of Porous Film / Fabric Composites for Vascular Scaffold Application

A composite vascular scaffold combining textile reinforced structure and biodegradable polymer is introduced, which may possess high porosity and connectivity.Moreover,the porous size could be controlled.The proposed scaffold consists of a warp-knitted poly( ethylene terephthalate)( PET) fabric with well-defined macropores, which is embedded with a porous biodegradable polymer membrane.The aim of this paper is to study the fabrication and properties of porous polymer membrane through optimizing the parameter of composite methods from freeze drying / particle leaching( FD/PL) and gas foaming /particle leaching( GF /PL),subsequently combining with the warp-knitted fabric.Weighing method was utilized to analyze the porosity of the samples and the scanning electron microscope( SEM) images were taken to observe the porous structure of the vascular membrane.In addition,the static contact angle( CA) was measured to estimate the hydrophilicity of the samples, and the tensile testing of the composites was performed on the universal mechanical tester.Furthermore, the water permeability of the membrane was also calculated.The results showed that the porosity and pore connectivity of the vascular membrane were diverse, because of solution concentration, particle size, ratio of content, etc.Meanwhile,the stress-strain curves and the bursting strength showed the different mechanical properties among composite scaffolds in different structures.

丙烯酸树脂复鞣剂的亲水性对无铬鞣皮革性能的影响

无铬鞣革普遍存在亲水性强、纤维分散不足等问题,通过调控复鞣材料的亲疏水性来设计适用于无铬鞣革的复鞣剂可能是解决该问题的有效策略。研究了丙烯酸-甲基丙烯酸长链烷基酯合成的丙烯酸树脂复鞣剂(AR)的亲水性(羧基单体含量)对有机无铬鞣革性能的影响。结果表明,随着羧基单体含量的增加,AR的粒径逐渐减小、表面负电荷增加,其在无铬鞣革内的渗透深度和分布均匀度增加。当丙烯酸单体的含量为45%时,AR能完全渗透坯革,且所得复鞣坯革的纤维分散程度、疏水性能、耐干热稳定性、撕裂强度、抗张强度等最高。由此可见,设计亲疏水性合适的AR对改善无铬鞣皮革的综合性能具有重要意义。

Synthesis and Properties of Fumed Silicas Modified with Mixtures of Poly(methylphenylsiloxane) and Dimethyl Carbonate

Effect of the concentration ratios of organosiloxane/initiator and treatment temperature on the characteristics of hydrophobic products obtained by modification of surface of fumed silica with poly(methylphenylsiloxane) (PMPS) in the presence of dimethyl carbonate has been studied. Morphology, particle size, surface area and coating microstructure of modified silicas were analyzed by methods of transmission electron and atomic force microscopies, nitrogen adsorption-desorption data. Carbon contents in the grafted modifying layer of organosilicas were determined using IR spectroscopy and elemental analysis. Hydrophilic-hydrophobic properties of surface of the obtained modified silicas were estimated by measurements of contact angles of wetting. It was shown that modification of pyrogenic silicas with mixtures of poly(methylphenylsiloxane) and dimethyl carbonate allows to obtain the homogeneous hydrophobic products and serve their nanodispersity.

低温氮等离子体对聚乳酸薄膜表面性能的改性

文中利用朗缪尔探针对低温氮(N2)等离子体进行了诊断,探究了电子密度随射频功率、压强、轴线距离的变化情况。利用水接触角表征了右旋聚乳酸(PDLA)改性前后亲水性变化,探究了改性PDLA膜的最佳条件。利用原子力显微镜、X射线衍射、热重分析仪、X射线光电子能谱表征了改性前后PDLA膜的表面形貌、晶体结构、热稳定性能及表面元素的变化。通过测量拉伸强度、断裂伸长率、透光率表征了改性前后PDLA膜力学性能、阻隔性能的变化。结果表明,在最佳条件下(射频功率100W、压强25Pa、改性时间180s、轴向距离10cm),PDLA膜的接触角从89.53°下降至49.96°;改性后PDLA膜的力学性能略有降低,在放电中心处拉伸强度和断裂伸长率比原膜分别降低了26.31%(横向)、24.41%(纵向)和29.41%(横向)、28.1%(纵向);热稳定性能较原膜略有增加,阻隔性能基本保持不变;随着储存时间的延长,PDLA膜的接触角不断增加,当存储30d时,样品仍保留了部分改善的亲水性。

聚己内酯/聚丁内酰胺电纺纤维的制备及性能

通过溶液静电纺丝法制备了聚己内酯/聚丁内酰胺(PCL/PBL)电纺纤维膜。采用扫描电子显微镜(SEM)、水相接触角测量仪、原子力显微镜(AFM)、能谱仪(EDS)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、热重分析仪(TGA)、差示扫描量热仪(DSC)、电子万能拉力机对PCL/PBL电纺纤维的形貌、亲疏水性、结晶性能、热性能及力学性能进行了研究。结果表明,随着PBL含量的增加,纤维直径增大、分布变窄,且纤维膜的亲水性明显改善;PCL与PBL有一定相容性,PCL/PBL电纺纤维膜的结晶度高于PCL或PBL均聚物电纺纤维膜,并随PBL含量增加而提高;PCL/PBL电纺纤维膜中PCL熔点随PBL含量增加而略有增加,PBL组分的熔点则基本不变。两组分的结晶温度和纤维膜热稳定性均随PBL含量增加而降低。PBL的加入使电纺纤维膜的力学性能明显提高。

水性聚氨酯组成结构与力学性能的关系及其染色性能的研究进展

与传统溶剂型聚氨酯相比,水性聚氨酯(WPU)大大减少了有机溶剂的使用,可有效降低环境污染,正越来越受到人们的关注。然而,WPU中亲水基团的引入会影响其力学性能,限制了WPU产品的使用范围。本文对WPU组成结构和力学性能之间的关系进行了阐述,并对WPU染色方面的研究现状做了介绍和总结,以期为水性聚氨酯超纤革的开发提供借鉴和参考。

不同端环氧硅油制备的三元共聚亲水硅油的性能

以端氢硅油、烯丙基环氧聚醚(JM501)为原料,通过硅氢加成反应制得端环氧聚醚硅油;以端氢硅油、烯丙基缩水甘油醚(AGE)为原料,通过硅氢加成反应制得端环氧硅油;以环氧双封头扩链体GH-1000、八甲基环四硅氧烷(D4)为原料,通过开环扩链制得端环氧硅油。将3种工艺制得的端环氧硅油分别与聚醚胺和改性剂反应制得三元共聚亲水硅油,比较不同亲水硅油整理织物的手感、亲水性、耐洗性以及亲水硅油在不同条件下的稳定性。结果表明:以端氢硅油、烯丙基环氧聚醚为原料,通过硅氢加成反应制得的端环氧聚醚硅油更适合合成亲水硅油,其整理的织物手感软滑、亲水性好、耐洗性好。

羊毛角蛋白融合型丝素蛋白膜材料的性能分析

羊毛角蛋白关联蛋白(KAPs)是一类富含半胱氨酸的纤维蛋白,可以氧化形成二硫键,与疏水相互作用和范德华力一起赋予角蛋白高的机械强度和结构稳定性。为了扩展天然蚕丝蛋白质材料的研究,本文以通过转基因法得到的KAP融入型蚕丝为材料,制备丝素蛋白膜,检测分析了膜的结构和性能。发现转KAP基因丝素膜含有更多的β-折叠结构,KAP的融入可以显著提高膜的机械性能和疏水性,融入不同种类的KAP可以获得性能不同的融合蛋白材料。通过转基因法制取蚕丝/羊毛角蛋白混合蛋白膜具有方法简便、无污染等特点,可为天然蚕丝材料的研究和应用提供新的思路。