氨基硅ASO-702在再生纤维素表面的膜形貌及其定向排列方式

以再生纤维素作基质,在其表面组装了N-环己基-γ-氨丙基聚二甲基硅氧烷(ASO-702),分别用X射线光电子能谱(XPS)、原子力显微镜(AFM)以及接触角测定仪对ASO-702的膜形貌进行了观察和表征.结果表明,在再生纤维素基质表面,氨基硅ASO-702能形成均一相疏水膜,该膜能有效降低再生纤维基质表面的粗糙度.XPS和接触角测定仪对纤维表面分析的结果表明,在处理后的棉纤维表层确有ASO-702硅膜存在,而且该膜疏水,接触角达到91.5°.从而进一步证明了氨基硅在纤维表面的定向排列成膜方式为:硅甲基朝外、Si-O偶极键及阳离子化氨基指向纤维表面.     

聚β-羟基丁酸酯/羟基磷灰石复合材料的制备与性能

用聚丙烯酸（PAA），甲苯二异氰酸酯（TDI），硅烷KH－550，KH－570对羟基磷(HA）了表面接枝处理，再与聚β-羟基丁酸酯（PHB）复合制备了PHB／HA复合材料。同时也采用先溶解HA，再让其直接析出在PHB表面的方法制备了PHB／HA复合材料。结果表明，增进复合材料中两相间的相互作用能明显地提高得合材料的力学性能。     

溶胶-凝胶原位生长制备超疏水木材

采用溶胶-凝胶原位生长的方法制备超疏水木材,在木材表面形成一层纳米结构超疏水薄膜,水滴在木材表面接触角达到150.6°。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、傅立叶变换红外光谱仪(FTIR)分别对超疏水木材样品的物相组成、表面形貌及表面化学官能团进行检测,分析表明木材的超疏水性是表面纳米级突起粗糙结构和乙烯基疏水基团共同作用的结果。     

聚偏氟乙烯-氟化二氧化硅有机-无机复合膜的制备及脱硫性能

以聚偏氟乙烯(PVDF)为基膜材料,通过溶胶凝胶-氟化法在PVDF膜表面沉淀氟化的二氧化硅纳米颗粒(fSiO_2),制备聚偏氟乙烯-氟化二氧化硅(PVDF-fSiO_2)有机-无机复合膜。通过衰减全反射傅里叶变换红外光谱、X射线光电子能谱、场发射扫描电子显微镜、接触角测定仪等对PVDF-fSiO_2复合膜进行表征,并评价其脱硫性能。结果表明,PVDFfSiO_2复合膜表面的接触角为106.9°,明显高于PVDF膜的76.4°;由于PVDF-fSiO_2复合膜的良好疏水性能和fSiO_2粒子对基膜的保护作用,随着脱硫时间的延长,PVDF-fSiO_2气-液膜接触器的脱硫率基本保持在79%左右。     

聚(3,3,3-三氟丙基)甲基/N-β-氨乙基-γ-氨丙基甲基硅氧烷的合成及其构筑的超疏水织物

以KOH为催化剂,实现了1,3,5-三甲基-1,3,5-三(3,3,3-氟丙基)环三硅氧烷(DF3)和N-β-氨乙基-γ-氨丙基甲基二甲氧基硅烷(APAEDMS)的本体聚合,得到了侧链含(3,3,3-三氟丙基)和N-β-氨乙基-γ-氨丙基的聚甲基硅氧烷(FASO),并以其为低能物质,结合凝胶-溶胶法将普通棉织物构筑为接触角为156°的超疏水织物。红外光谱(IR)和核磁共振(1 H-NMR)分析表明FASO具有预期的化学结构,处理前后织物表面SEM和疏水性分析表明:织物自身具有的微米尺度二维粗糙度和FASO修饰所形成的低能表面是织物变疏水的主要原因,纳米SiO2在纤维束表面构建的纳米尺度粗糙度,可将水在纤维-水接触面间所占分率由34.7%降低到10%,接触角由134.5°提高到156°。最后,用X-射线光电子能谱(XPS)对超疏水织物的表面成分进行了分析。     

N-β-氨乙基-γ-氨丙基聚二甲基聚二苯基硅氧烷的膜形貌及其XPS分析

利用八甲基环四硅氧烷D4与氨基硅烷以及二苯基二甲氧基硅烷等的聚合反应,合成了一种N-β-氨乙基-γ-氨丙基聚二甲基聚二苯基硅氧烷(PASO),用原子力显微镜AFM、光电子能谱XPS等仪器研究了PASO的成膜形态、表面相组成及膜的表面性能。结果表明,在单晶硅表面,PASO可形成略显粗糙的疏水性硅膜,在其表面有纤细尖峰存在。因此,在观察标尺为3 nm、扫描范围为2μm×2μm的条件下,PASO膜表面的均方根粗糙度达到了0.228 nm。     

吸附-扩散模型与溶解-扩散模型及其修正模型的相互关系

研究了吸附-扩散模型(ADM)与溶解扩散模型(SDM)及其修正模型的相互关系,对溶解-扩散模型(SDM)、扩展-溶解扩散模型(ESDM)、不完全的溶解扩散模型(SDIM)中参数作了进一步解释.吸附-扩散模型(ADM)的一级近似表达式与溶解-扩散模型(SDM)及其修正模型的数学形式和物理意义相似,验证了吸附-扩散模型(ADM)的正确性.     

透明超疏水表面的制备与抑霜性能研究

本文介绍了一种透明超疏水表面的制备方法,并在冷表面温度(-3～5℃)、相对湿度(20％～60％)下研究了其抑霜性能.结果表明:用纳米二氧化硅和聚二甲基硅氧烷制备的透明超疏水玻璃表面的最大接触角可达到154.1°,透光性能良好;在自然对流条件下竖直放置的超疏水玻璃表面有良好的抑霜效果,形成的霜层先是呈麦穗状,后期呈无规则...     

仿生超疏水棉织物的制备与表面分析

以荷叶表面微/纳米结构为参考模型,先用硅溶胶处理天然棉织物,再用N-β-氨乙基-γ-氨丙基聚二甲基硅氧烷(ASO-1)对其进行修饰,获得了微/纳米二元粗糙的超疏水织物,水滴在该织物表面接触角可达160.5°。场发射扫描电子显微镜(FE-SEM)观察发现超疏水纤维表面存在大量均匀分布的纳米微凸体。接触角分析表明织物织造过程中形成的微米级粗糙度和ASO-1膜的存在是织物疏水的主要原因,纳米微凸体能减少纤维与水的接触面积,提高水在纤维表面的接触角,使织物由疏水转变为超疏水。最后用X射线光电子能谱仪(XPS)证实了纤维表面SiO2粒子和ASO-1膜的存在。     

二氧化硅凝胶的疏水改性及表征

以正硅酸乙酯为原料,经溶胶-凝胶过程制备二氧化硅溶胶,再利用二甲基二乙氧基硅烷(DDS)对其进行改性,制备疏水性二氧化硅凝胶.用红外光谱、接触角,热重分析及原子力显微镜等测试方法对试样的结构、疏水性、热稳定性及形貌进行分析.结果表明,改性后的样品是表面存在疏水基团—CH3的疏水凝胶;热稳定性较好,600℃之后没有明显的质量损失,热处理温度定于400℃可保证其疏水性;表面均一平整,孔隙率较高.     

Superhydrophobic thin films with nanostructured surface prepared with Au nanoparticle masks

The hydrophobicity of a perfluoropolyether bisurethane methacrylate polymer film was investigated along with the formation of nano-hairs on its surface through reactive ion etching using gold nanoparticles (Au NPs) as masks. It was found that the hydrophobicity of the polymer film was strongly dependent on the number density of the nano-hairs which was determined by that of the Au NPs. The superhydrophobic surface was obtained when the number density was higher than 250 microm(-2). The effects of surface functionalization, Au NP immobilization, and etching time on the hydrophobicity of the polymer film were also examined extensively and discussed based on the results of the contact angle measurements and the scanning electron microscopy.     

No relationship between the cell surface hydrophobicity of coagulase-negative staphylococci and their ability to adhere onto fluorinated poly(ethylene-propylene)

The cell surface hydrophobicity of 14 encapsulated and 21 non-encapsulated coagulase-negative staphylococci (CN staph) as determined with the salt aggregation test (SAT) as well as with the xylene-water method ranged widely. Non-encapsulated strains adhered well onto fluorinated poly(ethylene-propylene) (FEP), irrespective of the hydrophobicity of the cell surface. The ability of the encapsulated strains to adhere onto FEP differed also considerably, but no correlation between the number of adherent bacteria and the cell surface hydrophobicity was observed.     

Effect of Heat Treatment on Silica Aerogels Prepared via Ambient Drying

Silica aerogels were prepared at ambient drying by using ethanol/trimethylchlorosilane （TMCS）/heptane solution as pore water exchange and surface modification of the wet gel before drying. The obtained silica aerogels exhibit a sponge-like structure with uniform pore size distribution. The effects of heat-treatment on the hydrophobicity, specific surface area and other properties were investigated. The results indicated that the hydrophobicity of silica aerogels could be maintained up to 350℃. With increasing heating temperature, hydrophobicity decreased, and became completely hydrophilic after heat-treatment at 500℃. Brunaueremmitt-teller （BET） surface area results indicated that the specific surface area of silica aerogels increased with increasing heating temperature in the range of 150-500℃. The effects of heat-treatment on the morphology and chemical bonding state of silica aerogels were investigated by scanning electron microscopy （SEM）, differential temperature analysis （DTA） and Fourier-transform infrared spectroscopy （FT-IR）.     

Aerosol assisted depositions of polymers using an atomiser delivery system

The hydrophobicity, robustness and anti-microbial properties of Sylgard 184 polymer films deposited via AACVD were optimised by using aerosol droplets from an atomiser delivery system, polymer coating substrates and the swell encapsulation of methylene blue. By using an atomiser deposition system (average droplet size 0.35 microm) rather than a misting aerosol system (45 microm) lead to a surface with smaller surface features, which improved hydrophobicity (water contact angle 165 degrees) in addition to increasing the films transparency from ca 10 to 65%. Pre-treating the substrates with the same Sylgard 184 elastomer lead to a highly consistent surface hydrophobicity and an increase in average water contact angle measured (169 degrees). This paper shows the first example of dye incorporation in a CVD derived polymer film-these films have potential as antimicrobial surfaces.     

Comparison of pyrolysis and oxidation actions on chemical and physical property of anthracite coal surface

Hydrophobicity of coal surface is determined by its physical property and chemical composition. Once coal was oxidized or spontaneously ignited under natural conditions, the surface properties would change greatly, which inevitably affect the hydrophobicity of coal surface. To reveal the changing regulations of coal surface’s hydrophobicity after oxidation and pyrolysis treatment, in this paper, two conditions (pyrolysis and oxidation) of heating treatment were used to produce a series of coal surfaces, and then characterizing their physical and chemical properties through SEM and XPS. Meanwhile, induction time and flotation tests were performed to measure the hydrophobicity of coal. Results showed that the pores and cracks were well developed on the coal surface after both oxidation and pyrolysis processes. But they contributed to opposite aspects later in the flotation test. Additionally, the content of oxygen-containing functional groups on the surface decreased after pyrolysis, whereas having a sharp increase after the oxidation process, which predicted that the hydrophobicity of coal surface under two heating conditions would be completely different. Coal after pyrolysis owned a very short induction time, and its flotation recovery was high. For oxidation process, the coal surface became more hydrophilic and their induction time could reach at about 4000 ms, very hard to float.     

微波对大豆分离蛋白结构及其膜性能的影响

目的探究微波和离子型表面活性剂处理对大豆分离蛋白结构及其膜性能的影响。方法应用微波以及离子型表面活性剂十二烷基硫酸钠(SDS)对大豆分离蛋白成膜液进行处理,并采用倾倒法成膜。结果微波处理可以使大豆分离蛋白(SPI)紧凑有序的结构在一定程度上舒展,暴露出更多的活性基团,同时,也可以使隐藏于大豆蛋白内部的疏水基团暴露,促进大豆分离蛋白侧链之间形成氢键,与SDS形成疏水键,并产生静电结合,形成空间网络结构。同时,甘油与SPI之间形成的氢键可以使这种结构更加稳定。与对照组相比,经过微波处理的大豆分离蛋白膜具有更高的机械强度以及更好的表面疏水性。当微波功率为400 W时,膜的抗张强度较对照组提高了61.91%,断裂伸长率提高了453.75%,同时,膜也呈现出较好的表面疏水性。结论微波以及离子型表面活性剂处理可以使大豆分离蛋白膜具有更高的力学性能和表面疏水性。     

Effect of hydrophobicity on in vitro streptococcal adhesion to dental alloys

Non-specific interactions such as electrostatic interactions, and surface free energy are of importance in bacterial adhesion to dental surfaces as they determine whether or not bacteria are attracted to the surface. The relationship between adherence of Streptococcus mitis, S. mutans, S. oralis and S. sanguinis on precious and non-precious dental alloys, and the bacterial and alloy surface hydrophobicities (a measure of the surface free energy) was studied. The number of adhering bacteria was determined by fluorescence microscopy counts. The hydrophobicity of the bacteria and alloy surfaces were evaluated by adhesion to hexadecane and water contact angles, respectively. Our results showed that (i) the surfaces of the tested alloys were hydrophobic, (ii) S. sanguinis, S. mutans and S. oralis were hydrophobic, and (iii) S. mitis was hydrophilic. S. oralis, the more hydrophobic strain, demonstrated the highest adherence on the tested materials, whereas S. mitis adhered least on the hydrophobic surfaces. For the tested alloys, bacterial adherence was highest for the high gold content alloy, and lowest for the non-precious alloy. Our results showed that for the tested bacterial strains, there was a significant correlation between bacterial adhesion and substratum hydrophobicity: hydrophobic metal surfaces favor adhesion of hydrophobic bacteria.     

Effect of surface metrology on the wettability of SiO2 nanoparticle coating

In this work, we fabricated an array of model hydrophobic surfaces with controlled roughness to establish a correlation between surface structure and observed hydrophobicity. SiO₂ nanoparticles of different sizes (7, 12, 14 and 40 nm) were layer-by-layer spin-coated on glass supports to study the effect of surface roughness on wettability evaluated by water contact angles. The hydrophobicity of one-layer structured surfaces improved with an increase in particle size. Deposition of bigger nanoparticles on top of smaller ones, generating double-layer structures, resulted in rougher surfaces with higher hydrophobicity. A strong correlation between the size ratio of deposited nanoparticle combinations and roughness was observed. Based on these correlations, it is now possible to tune surface roughness and subsequent wettability by controlling the sizes of the nanoparticle layers.     

Hierarchical silicon etched structures for controlled hydrophobicity/superhydrophobicity

Silicon surface hydrophobicity has been varied by using silane treatments on silicon pyramid surfaces generated by KOH anisotropic etching. Results demonstrated that by altering the surface hydrophobicity, the apparent contact angle changed in accord with the Wenzel equation for surface structures with inclined side walls. Hierarchical structures were also constructed from Si pyramids where nanostructures were added by Au-assisted electroless HF/H2O2 etching. Surface hydrophobicity and superhydrophobicity were achieved by surface modification with a variety of silanes. Stability of the Cassie state of superhydrophobicity is described with respect to the Laplace pressure as indicated by the water droplet meniscus in contact with the hierarchical structures. The contact angle hysteresis observed is also discussed with respect to water/substrate adhesion.     

氟化PVA-SiO2薄膜单面疏水性的研究与表征

目的 研究开发一种具有单面疏水性能的聚乙烯醇薄膜材料作为包装材料。方法 将质量分数为12%、醇解度为88%的PVA溶液与质量分数为5%的纳米SiO2溶液按体积比为1∶1混合并加热搅拌,通过流延干燥的方式制备PVA-SiO2薄膜。然后分别用体积分数为2.5%,5%,7.5%的十七氟癸基三甲氧基硅烷（FAS）-乙醇溶液以浸泡方式修饰薄膜的其中一面,并通过溶解性测试、接触角测试、场发射扫描电子显微镜（FE-SEM）、傅里叶变换衰减全反射红外光谱测试（ATR-FTIR）等方法表征改性结果。结果 结果表明薄膜单面疏水性得到改善,改性后的薄膜在水中的溶解时间增加,且接触角均在120°以上,表明FAS起到了降低表面能的作用;FE-SEM结果显示,Si元素含量对薄膜的疏水性能有着重要影响;ATR-FTIR显示,FAS改性成功将氟原子引入到薄膜表面,且增加了硅原子的数量。其中用质量分数为5%的FAS-乙醇溶液修饰后的薄膜疏水性最好,接触角达到了126.21°。结论 与未改性薄膜相比,经FAS单面疏水改性的PVA-SiO2薄膜疏水性能得到大大提高,拓宽了PVA薄膜材料的应用领域。