Preparation of a high hydrophobic aluminium surface by double zincating process

In this present study, an efficient method has been proposed to develop a high hydrophobic zincated coating on the eva-core aluminium (Al) alloy surface. The double zincating method (Z2) was utilized to develop the required roughness on the Al surface. To control the surface energy, lauric acid (LA) was coated on the surface using the liquid self-assembled monolayers (L-SAMs) method. Surface morphology, the chemical composition of the treated and untreated Al alloy has been studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), optical microscopy and X-ray diffraction (XRD), respectively. The hydrophobicity of the substrates has also been analysed using a contact angle measurement (CA). AFM micrographs show the surface roughness of the Al alloy has been drastically increased with chemical treatments from 0.071 to 0.32 μm. XRD shows the percentage crystallinity of the Al alloy is decreased with double zincating and LA coating from 56.8 to 22.7%. As a result, a high hydrophobicity of Al alloy was induced with a contact angle of 150° upon the double zincating method and L-SAMs coating.     

Effect of alcohol pretreatment in conjunction with atmospheric pressure plasmas on hydrophobizing ramie fiber surfaces

To improve interfacial adhesion between hydrophilic cellulose fiber and hydrophobic polymer matrix, ramie fibers were pretreated with isopropanol and n-butanol and then plasma treated using an atmospheric pressure plasma apparatus. For the plasma-treated fibers, the scanning electron microscopy shows increased surface roughness and the X-ray photoelectron spectroscopy analysis shows a significant increase of C–C bond in isopropanol-pretreated group, whereas for n-butanol-pretreated group the raise of C=O bonds is most noticeable. For both alcohol-pretreated and plasma-treated groups, the water contact angles increase significantly. Microbond pull-out test shows interfacial shear strengths of fiber/polypropylene (PP) samples increase by 47 and 34%, respectively, for the two groups compared with the control. Therefore, it can be concluded that the reaction between both alcohols and cellulose induced by plasma can indeed create a fiber surface with increased roughness and decreased polarity, and thus is more compatible to PP.     

基于动态接触角的硅橡胶憎水性表征方法的研究

当硅橡胶受到侵蚀和染污时,由于表面变得粗糙和溶质沉淀,导致接触角测量存在滞后效应,为了更合理表征硅橡胶的憎水性,将动态接触角方法用于硅橡胶憎水性的表征。该方法对材料表面通过注水/抽水的方式获得前进角/后退角。对洁净、浸泡、电晕和表面染污后的室温硫化硅橡胶涂层样本分别使用静态接触角方法、动态接触角方法进行测量。结果发现,浸泡、染污、电晕后的样本两种方法所得结果差别较大,静态接触角测量随机性较大且易受拍照时延的影响,对表面憎水性的表征能力不够,后退角能很好地表征材料的憎水性,后退角越小,则材料表面越容易被浸润。文中同时对浸泡、电晕、染污前后表面的粗糙度增加、溶质沉淀原因进行了分析,理论上解释了接触角测量的滞后效应。笔者的研究对硅橡胶及高分子材料的憎水性研究具有一定参考价值。     

微孔硅酸钙憎水性研究

针对微孔硅酸钙制品吸湿吸水性大的特点，采用有机硅渗透处理，在制品表层生成一层憎水薄膜。结果表明：其憎水效果优良。本文还对其憎水机理进行了分析。     

尼龙6/笼形八苯基硅倍半氧烷复合材料的结构与性能

以熔融混合方法制备了尼龙6/笼形八苯基硅倍半氧烷(PA6/OPS)复合材料,并采用扫描电子显微镜、偏光显微镜、示差扫描量热(DSC)、X 射线衍射(XRD)等方法对复合材料的形态、力学性能、疏水性能及结晶性能进行了研究。实验结果表明,OPS在 PA6基体中形成团聚体,当 OPS 质量分数为2%时,PA6/OPS 复合材料的拉伸强度和屈服强度较 PA6有所改善,断裂伸长率和弹性模量明显提高;添加 OPS 增大了 PA6的水接触角,降低了相对吸水率,即提高了 PA6的疏水性;OPS 使 PA6的球晶尺寸减小,球晶的数量增多;添加 OPS 后,PA6存在两种晶型,结晶温度向高温方向移动,OPS 在 PA6基体中起到成核剂的作用。     

Spherical Nanoparticle Arrays with Tunable Nanogaps and Their Hydrophobicity Enhanced Rapid SERS Detection by Localized Concentration of Droplet Evaporation

Periodic hexagonal spherical nanoparticle arrays are fabricated by a sacrificial colloidal monolayer template route by chemical deposition and further physical deposition. The regular network‐structured arrays are first templated by colloidal monolayers and then they are changed to novel periodic spherical nanoparticle arrays by further sputtering deposition due to multiple direction deposition and shadow effect between adjacent nanoparticles. The nanogaps between two adjacent spherical nanoparticles can be well tuned by controlling deposition time. Such periodic nanoparticle arrays with gold coatings demonstrate a very stable and high sensitive surface‐enhanced Raman scattering spectroscopy (SERS) performance. The periodic nanoparticle arrays with 10 nm gaps display much stronger SERS enhancement due to electromagnetic coupling. The chemically modified nanoparticle arrays show good hydrophobicity, which shorten process of detecting probe molecules using them as SERS‐active substrates by localized concentration of droplet evaporation and a low detection limit of 10⁻¹² m R6G can be achieved without solution wasting in a short time. The hydrophobic substrate offers a simple, convenient, and economical method to examine SERS performance by rapid concentration of solution on it and it is highly helpful to improve its practical applications in portable Raman detecting devices to detect organic molecules.     

Enhanced antiviral activity of soybean β-conglycinin-derived peptides by acylation with saturated fatty acids

Abstract: Peptide mixtures prepared from soybean β‐conglycinin (7S‐peptides) were acylated with saturated fatty acids of different chain length (6C‐18C) in order to improve their antiviral activity against Feline calicivirus (FCV) strain F9 which is a typical norovirus surrogate. Among the fatty acids varieties, it was revealed that 7S‐peptides acylated with myristic and palmitic acids potently inhibited FCV replication. Myristorylation and palmitoylation of 7S‐peptides kept host cells viability at 91.51% and 98.90%, respectively. The infectivity of FCV on Crandell–Reese feline kidney cells was further determined after exposure of initial titer of 10^6.47 TCID₅₀/mL. Myristoylated and palmitoylated 7S‐peptides significantly (P < 0.006) reduced FCV infectivity as compared to native 7S‐peptides. Native 7S‐peptides showed 25% FCV inhibitory activity while myristoylated and palmitoylated 7S‐peptides exhibited 98.59% and 99.98% reduction in FCV infectivity, respectively. Myristoylated and palmitoylated 7S‐peptides demonstrated higher anti‐FCV activity in a wide range of concentration with complete reduction at 25 μg/mL. Surface hydrophobicity was significantly (P < 0.05) increased after attachment of long hydrocarbon fatty acids to 7S‐peptides as supported by changes in fluorescence intensity. Enzymatic hydrolysis together with acylation will give an insight into surface and physiological functional lipopeptides derived from soy β‐conglycinin.     

铁路隧道复合绝缘子运行特性分析

抽取了1支在铁路隧道内挂网运行的复合绝缘子,该绝缘子在运行时表面放电频繁,为了研究该绝缘子运行性能,在实验室进行了自然污闪电压、憎水性、材料拉伸强度、撕裂强度和硬度试验,利用离子色谱仪、电子扫描显微镜、X射线衍射分析、拉曼光谱对硅橡胶表面污秽进行分析,研究结果表明该绝缘子自然污闪电压较高,表面憎水性整体较差,憎水丧失及...     

Prediction of signal peptide functional properties: a study of the orientation and angle of insertion of yeast invertase mutants and human apolipoprotein B signal peptide variants

A number of studies have introduced mutations into the yeastinvertase signal peptide, using it as a model system to elucidatefeatures for targeting, translocation and intracellular transportUsing molecular modelling of the invertase signal peptide wehave analysed the hydrophobicity potential and the change inthe dielectric constant of the energy transfer, when the moleculemoves from a hydrophobic to a hydrophilic phase at the simulatedhydrophobic-hydrophilic interface. This modelling has been carriedout on wild type and mutant invertase signal peptides of alteredfunction, previously reported in the literature. While the predictedangle of insertion correlates with the measured extent of invertasesecretion, with an optimum angle of 45, mutations that changethe angle of orientation reduce the extent of invertase secretion.We have applied these same molecular modelling principles tothe naturally occurring variants of the human apolipo-proteinB (apoB) signal peptide, that confer a secretion defective phenotypewhen fused to yeast invertase and expressed in yeast. Our modellingthus identifies a strong correlation between the predicted angleof insertion of the signal peptide into the membrane and itsability to direct secretion.