高疏水纳米二氧化硅薄膜的制备

溶胶凝胶方法制备高疏水薄膜,加入胶体二氧化硅粒子和TMCS控制薄膜表面粗糙度和表面化学性质。薄膜表面具有很大的表面粗糙度,使薄膜体现出很好的疏水性能。这种方法能够实现一步法大面积不规则镀制薄膜,具有一定的实用价值.     

利用胶体粒子团聚制备透明超疏水纳米二氧化硅薄膜

溶胶-凝胶法制备超疏水薄膜，加入胶体二氧化硅粒子和氟硅烷控制薄膜表面粗糙度和表面化学性质。胶体粒子团聚使薄膜表面具有很大的表面粗糙度，使薄膜体现出很好的疏水性能。     

电瓷绝缘子表面SiO2疏水薄膜的制备

本文利用溶胶凝胶法、酸碱不同催化溶胶相混合,经过热处理,在电瓷片表面制备了具有双重粗糙度的二氧化硅薄膜,形成类似荷叶的微观结构,然后用硅烷偶联剂(SCA)化学气相修饰,在薄膜表面自组装一层SCA分子,得到超疏水薄膜。利用半球法测接触角,用单因素实验方法研究酸碱两种催化方式下的溶胶浓度比、热处理温度、修饰温度对疏水性能的影响。结果表明:酸碱溶胶相结合达到了提高薄膜粗糙度的效果,其耐候性和附着性能能够满足绝缘子等瓷制品的使用要求。     

基于金属模板热压微模塑制备聚烯烃超疏水表面

超疏水表面如薄膜由于具有重要应用前景而广受关注,但目前仍缺少能够经济、大规模制备方法.本研究先用不同配比的蚀刻液分别对不锈钢、黄铜、铝合金表面进行可控刻蚀,得到具有适当粗糙度的系列金属表面,再以此金属表面为模板,通过热压微模塑-拉伸工艺制得了聚烯烃超疏水表面,接触角大于150°,滚动角小于5°.扫描电镜照片显示超疏水表...     

粗糙疏水表面冷凝形核特性研究

为了研究疏水基底粗糙度对形核特性的影响规律,采用腐蚀及修饰的方法得到具有不同粗糙度的疏水基底,通过对基底表面粗糙度因子的计算和表观润湿角的测量,考察了基底粗糙度对基底表面水的表观润湿角的定量关系;在制备的粗糙基底上进行了冷凝蒸汽形核实验,利用统计方法得到基底粗糙度因子与冷凝液滴数量的关系。结果表明:基底微观形貌对水在基底表面的表观润湿性和形核特性具有显著影响,对于疏水基底,随着基底粗糙度的增加,水滴在其表面的表观润湿角增大;相同的基底过冷度下,越粗糙的基底表面蒸汽冷凝形核点越少。分析认为,基底微观形貌通过影响液胚在其表面的表观润湿角,进而改变异质形核功,造成了粗糙基底表面形核特性的改变。实验现象与基于Wenzel模型的粗糙基底异质形核理论取得了一致。     

基于光固化微压印制备仿生荷叶疏水薄膜的研究

采用光固化微压印制备仿生疏水薄膜的工艺方法,制备了具有荷叶表面微结构的聚二甲基硅氧烷(PDMS)软模具,在此基础上,制备了仿生疏水薄膜,探究了紫外光辐照时间、辐照强度等对疏水薄膜水接触角的影响。结果表明,PDMS模具能够较好地复印荷叶表面的微结构,增加辐照时间和辐照强度改变压印压力可以有效提高疏水薄膜的疏水性,当辐照强度为1 000 mW/cm~2、压印压力为0.2 MPa、辐照时间为20 s时,制备的仿生疏水薄膜的表面接触角达到153.5°。     

PET薄膜表面性能及其与紫外光固化涂层粘接性能相关性研究

通过粘结性能实验研究了表面处理方法对PET薄膜/紫外光固化涂层体系粘接性能的影响,结果表明:表面处理提高了PET薄膜/涂层体系粘接强度。研究了PET表面处理对PET表面性能如表面形貌、光泽度(粗糙度)、表面张力、表面官能团含量的影响,结果表明:PET薄膜经电晕处理后,其表面粗糙度有增大的倾向,而涂层处理对PET薄膜表面粗糙度无影响;经电晕处理和底涂处理后,PET薄膜表面张力均有增加,底涂处理提高PET薄膜表面张力的幅度更大。研究了PET薄膜表面性能与剪切强度的关系,发现PET薄膜/涂层粘接体系剪切强度τ与PET薄膜表面张力γ具有线性关系。     

ZnO超疏水/超亲水可逆转化薄膜研究进展

ZnO纳米薄膜具有光响应的润湿性可逆转化现象,这种"智能开关"在许多领域具有重要意义,为此近年来ZnO超疏水薄膜的制备引起了研究者的广泛关注。一般是在ZnO表面修饰一层表面张力较低的物质,通过降低表面自由能而获得超疏水表面。然而常用的修饰物质如氟化物、硅烷等会不同程度地被ZnO光催化分解。为此一方面积极寻求光催化稳定的修饰层,另一方面制备具有特殊形貌的ZnO纳米薄膜以期直接获取ZnO超疏水薄膜。由于离子液体的稳定性,利用其作为ZnO的修饰层制备双响应薄膜,另外用HAc调控制备"裸"ZnO超疏水薄膜。对ZnO润湿性能及其超疏水薄膜的制备研究进展进行了简要综述。     

置换反应制备锌表面超疏水薄膜

利用硫酸铜与锌的置换反应,在锌片表面生成具有微纳米结构的铜,制备锌表面超疏水薄膜。研究了硫酸的加入、硫酸铜浓度和反应时间对微纳米结构及疏水性能的影响。使用扫描电子显微镜(SEM)对表面结构进行了表征。使用接触角测量仪测量了疏水性。结果显示,在最优条件下接触角可达到154°,滚动角可达到6°。该超疏水薄膜具有一定的防腐蚀性。     

建筑用16Mn钢超疏水膜层的制备及耐蚀性研究

为提高建筑用16Mn钢的耐蚀性,采用磷化处理、铈盐钝化再经过硬脂酸修饰在16Mn钢表面制备出超疏水膜层。表征了膜层微观形貌和成分,并测试了表面粗糙度、水滴接触角和耐蚀性。结果表明:铈盐钝化、硬脂酸修饰后磷化膜的微观形貌、成分和表面粗糙度存在差异,导致表面润湿性和耐蚀性不同。只是通过增加表面粗糙度的方式无法制备出超疏水膜层,膜层呈亲水性或超疏水性与其耐蚀性之间存在关联性。钝化-修饰磷化膜表面水滴接触角达到150.7°,表现出超疏水性还具有良好的耐蚀性,能有效抑制16Mn钢腐蚀从而提高其耐蚀性。原因是钝化-修饰磷化膜表面形成微纳米粗糙结构,有利于俘获空气形成气垫,对腐蚀介质具有较好的阻隔作用,有效抑制腐蚀并降低腐蚀程度。     

由PR状态方程计算液体混合物表面张力

在界面化学位的基础上，定义了组分的界面逸度系数，推导出一个新的液体混合物表面张力的表达式，同时用Ｐｅｎｇ－Ｒｏｂｉｎｓｏｎ状态方程计算液体混合物体相和表面相组分的逸度系数，从而实现了由状态方程计算液体混合物表面张力。文中用这一新模型计算了５６个二元体系的表面张力，平均相对偏差为３．３８％，说明该方法是可行的。     

Experimental Approach to an Efficient and Versatile Water Filtration Vacuum Cleaner

A simple and robust suction technique is proposed for vacuum cleaning based on an innovative water filtration method for dry, wet, and water swab modes. The technique relies on applying vacuum above the free surface of water to drive the dust‐laden airstream to be released at constant depth below the water surface. Unlike conventional vacuum cleaner types, experimental measurements revealed that a high negative suction pressure availability and low exhaust air temperature with negligible and irrelevant increase in humidity levels were maintained regardless of the filling state. The proposed technique thus ensures more efficient utilization and conservation of energy.     

A robust iterative method of computing effectiveness factors in porous catalysts

A robust, efficient numerical method for computing the effectiveness factor of a heterogeneous reaction in a catalyst is developed in this study. The method is based on shooting at the outer surface of the catalyst and is optimized for an accurate estimation of the concentration gradient at the outer surface. The shooting at the outer surface, however, is inherently unstable for a cylindrical or a spherical catalyst, and it also can become unstable with an increasing Thiele modulus even for a slab catalyst. From an analysis of the governing equation, however, three criteria are developed to make the method work efficiently in the presence of instability. The numerical method is shown to be effective for diverse kinetic expressions, from simple power-law to sophisticated Langmiur-Hinselwood kinetics, and for isothermal or non-isothermal catalysts. The method is also shown to be easily applicable to a more complex case of multiple steady states, estimating all the corresponding effectiveness factors. In this method, a simple rule that determines the stability of each steady state is proposed.     

A revised surface tension model for macro-scale particle methods

A simple treatment for surface tension in immiscible fluids is proposed for macro-scale particle methods such as smoothed particle hydrodynamics (SPH) and macro-scale pseudo-particle modeling (MaPPM). By introducing a repulsion between the neighboring particles of different fluids, surface tension arises automatically, while simple equations of state are still possible for each phase. This treatment is validated by comparative simulations on the deformation of a square liquid drop in suspension using the volume of fluid (VOF) method. The relationship between surface tension and the repulsion intensity parameter in our model is obtained by the sessile drop method.     

A new model for the surface tension of binary and ternary liquid mixtures based on Peng- Robinson equation of state

Based on the surface chemical potential and Peng-Robinson equation of state,a newmodel is proposed to predict and correlate the surface tensions of binary and ternary liquid mix-tures.Using this method,the surface tensions of 73 binary and 8 ternary systems are calculatedwith average relative deviations 1.35% and 3.52% respectively.The proposed model is simple, re-liable and accurate.     

基于不停电检测的RTV防污闪涂料运行状况的评估方法

对宁夏地区RTV(室温硫化硅橡胶)防污闪涂料运行现状进行了分析,提出一种RTV涂料运行状况的评估方法。该方法是在设备不停电检测的情况下,根据RTV涂料表面特有外观量进行模糊综合判定,通过计算得到RTV涂料防污闪性能的综合评价值,定量地对RTV涂料的运行状况进行了评估。分析结果表明:该方法简单、实用,不需要停电就可较为准确地评估RTV涂料的运行状况,确保运行中的RTV涂料具有良好的防污闪能力。     

Fluorination of epoxy surfaces by a physical method

To enhance the surface hydrophobicity of epoxy polymers, a simple physical method for the simultaneous surface fluorination during curing of epoxy resins was proposed and evaluated. Curing of epoxy resins against a polytetrafluoroethylene (PTFE) mold gave rise to fluorinated epoxy polymer surfaces due to the anchorage of PTFE molecules on the epoxy polymer surface. The modified epoxy surfaces were characterized using contact‐angle measurements and X‐ray photoelectron spectroscopy (XPS). The fluorinated epoxy resin surfaces are highly hydrophobic, exhibiting contact angles of similar magnitude to that of the pristine PTFE film surface. The PTFE mold can be used repeatedly to give fluorinated epoxy surfaces with large contact angles. Aging and solvent extraction tests indicated that the fluorinated epoxy surfaces were very stable. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 296–304, 2000     

Simple fabrication of functionalized surface with polyethylene glycol microstructure and glycidyl methacrylate moiety for the selective immobilization of proteins and cells

This study reported simple surface modification for the immobilization of biomolecules such as proteins and cells onto desired area at micron-scale level. First, thin film composed of glycidyl methacrylate (GMA) was prepared by UV-photopolymerization. Then, the polyethylene glycol (PEG) microstructures which played a role in the prevention of nonspecific binding of biomolecules were fabricated by using micromolding in capillaries (MIMIC). Thus, we could easily obtain an orthogonal surface having biomolecular attraction and repulsion areas. In addition, we could control of the height of prepared PEG microstructures with spin coating or not. For the investigation of feasibility of biomolecule patterning onto the functionalized surface, FITC-BSA and HEK 293 were examined as representative biomolecule models. A functionalized surface with GMA promotes the strong adhesion of biomolecules, and PEG microstructures located on the background prevent nonspecific binding of biomolecules at micron-scale level. The orthogonal difference in surface functionality showed strong possibility of simple patterning of biomolecules. In addition, the proposed method could easily control the size, shape, and height of patterns. It will be useful platform technology for the construction of a biomolecule array.     

刚性换热网络的弹性化

针对给定的换热流程(刚性网络),以对换热面积作最小调整为目标,使重要物流达到工艺要求的目标温度以及消耗最少公用能为约束,建立1个NLP模型.该模型的解,将给出为使网络具有一定的操作弹性而必须对其中各物流间换热器的传热面积做出的调整值.具体应用例证明,此法简单可靠.由于合成刚性网络远比直接合成弹性网络简单,故本法与刚性网络的合成软件结合,可以更方便地做出弹性网络设计;在对现有换热流程进行改造时,由于该法以既成网络为基础,将做出工程量与投资最少的改造方案.