异形涤纶导湿性能研究

对异形涤纶的导温性能进行研究 ,设计了 7种异形孔并纺制纤维试样 ,分别测试它们的吸湿排汗能力、带液率、干燥速率。讨论同孔形不同尺寸的孔及不同孔形对异形纤维导湿性能的影响。结果发现 ,同孔形不同孔尺寸的异形纤维异形度随叶片长宽比的增加而增加 (控制在 7以下 ) ,纤维的吸湿功能与异形度有关 ,还与凹槽的深度、形状有关 ,H孔型的吸湿排汗功能最好     

低阶煤物理性质与化学组成对其润湿性影响

以神华新疆、神东两大矿区中8个矿的煤层煤样作为研究对象,应用Washburn法测试低阶煤煤粉毛细常数、接触角,考察了低阶煤物理性质及化学组成对其润湿性能的影响。实验表明:煤粉粒度分布、孔隙率等是影响低阶煤润湿性的结构因素。颗粒体积平均粒径(D_([4,3]))越小、90%颗粒粒径(D_(90))越小,毛细常数越大;随孔隙率增大,吸液速率增加,毛细常数越大,间接提高润湿特性。在低阶煤化学组成中,内水含量越高,接触角越小,低阶煤对水润湿性越好(线性相关系数R~2=0.81)。此外,元素分析结果与接触角关联发现,随C_(daf)、H_(daf)降低或者O_(daf)增加,煤粉与水接触角变小,表明了润湿性随含氧官能团(如羧基)含量的增加而变好,亲水性随煤化程度降低变强。     

气泡对过滤介质的堵塞机理

过滤介质的透水实验表明 ,清洁过滤介质的透水速率随时间延长而降低。水中所溶解的气体会吸际于过滤介质的纤维表面 ,并将滤布的孔隙堵塞 ,从而使过滤介质的透水速率逐渐降低。过滤介质的孔隙越小 ,纤维的疏水性越强 ,此现象越明显。     

油水分离聚结材料的制备与性能研究

研制了纳米颗粒沉积玻璃纤维作为新型聚结材料,考察了分散液浓度、沉积时间和纳米颗粒尺寸等因素对纳米颗粒在纤维表面沉积情况的影响,检测了表面纳米颗粒沉积玻璃纤维的脱水性能。结果显示分散液浓度和浸泡时间对纳米颗粒的沉积情况没有明显影响,但分散液浓度越高,未沉积在纤维表面的SiO_2颗粒越多;颗粒尺寸越小,在纤维表面沉积效果更好;其中经20 nm粒径SiO_2分散液处理的纤维聚结过滤效果最佳。     

聚结层排布对高压天然气净化用滤芯过滤性能影响的实验研究

本工作利用聚结滤芯过滤性能实验装置,通过改变滤芯内部的滤材排布,研究了聚结层为单一滤材以及由不同滤材排布组合的滤芯过滤性能,分析了聚结层排布方式对过滤效率、压降、饱和度及液体分布的影响。结果表明,由单一滤材组成的滤芯过滤效率随滤材孔径减小而增大,但孔径最小时由于压降较高,导致滤芯综合过滤性能反而最差。疏油在前、亲油在后的聚结层排布方式可提高滤芯过滤效率、减少液滴二次夹带,且以两层相同滤材交错排列的滤芯过滤效率比单层滤材交错排列明显更高,压降也相对较低,使得综合过滤性能显著提升。继续增加进气侧的疏油滤材层数可延缓压降增长、提高运行寿命,滤芯稳态品质因子达到最大值(0.30 kPa-1)。聚结层排布方式对滤芯过滤性能的影响主要通过改变液体分布形式而实现,且末层滤材的通道结构变化是导致不同聚结层排布方式的滤芯过滤性能出现差异的主要原因。     

烷基化中离子液体与烃分离的实验研究

针对离子液体烷基化反应流出物中的离子液体-烃乳化液体系,选用高效聚结纤维填料进行离子液体与烃分离实验,考察了离子液体对纤维材料的润湿性,并重点研究了采用聚结分离方法时,烷基化过程中离子液体与烃分离装置的防堵能力以及分离效果。实验结果表明,离子液体对改性纤维有较好的润湿性,该纤维填料聚结器防堵能力强且分离效果好。     

不同润湿表面液体沸腾的分子动力学模拟

采用分子动力学方法研究纳米尺度下液氩在过热基板上的沸腾过程。通过调节固液间相互作用的方式改变壁面润湿性，模拟并分析了壁面润湿性对沸腾过程中能量传递和液体运动情况的影响。结果表明：不同润湿性表面均会发生固液分离的现象，但是固体表面附近吸附的氩原子数密度随润湿性增强而增大；润湿性较强时，液体的能量上升快，热通量高，液体内部温度梯度大，发生固液分离时间早，系统中氩的温度和能量低，上升过程中液氩密度、厚度变化小；润湿性较弱时，液体的能量上升慢，热通量小，液体内部温度梯度小，发生固液分离时间延后，系统中氩的温度、能量更高，上升过程中液氩密度、厚度变化较大。下部气体压力整体上大于上部气体压力，发生固液分离时润湿性越强的表面上液体上下压差越大，首次上升过程能达到的高度越高，所需时间越短。     

疏油改性对玻纤聚结元件气液过滤性能的影响

气液聚结元件在压缩气体净化等工业领域应用广泛，目前聚结元件的性能难以满足行业不断增长的需求，但是提高聚结元件过滤效率的同时，阻力也会随之升高，不利于其综合性能的优化。为研制低阻高效的聚结元件，利用不同浓度氟硅氧烷丙烯酸酯溶液对聚结滤材进行疏油改性，分析了表面能不同的滤材在气液过滤过程中压降、过滤效率以及二次夹带现象的变化，并对改性在聚结滤芯上的应用效果进行研究。结果表明，改性滤材在过滤效率提高10%的同时，稳态压降可降低约30%。滤材表面性质变化导致的跳跃压降减小是稳态压降降低的主要原因；滤材内液体分布对扩散、惯性分离作用的增强以及二次夹带的减少是效率提高的主要原因。对于表面能不同的疏油滤材，稳态压降和效率均随表面能的减小而升高。聚结滤芯经过改性后品质因子最大可提高92%。     

操作参数对W/O乳状液水滴静电迁移聚并的影响

用导热油和蒸馏水配制成W/O乳状液，在高压高频脉冲电场下通过显微实验考察了含水率、乳化强度、温度等操作参数对高压高频脉冲电聚结和水滴迁移聚并的影响。结果表明，含水率低时，水滴碰撞几率和偶极聚结力的实验结果与理论分析结果相符，含水率高时脱水效果下降；乳化强度越强，水滴碰撞速率越大，偶极聚结力越小，乳化强度适中，电聚结效果越好；操作温度越高，布朗运动越强，连续相粘度越小，液膜排液阻力减小，对水滴聚结越有利。     

管道表面润湿性对层流流动阻力的影响

基于建立的小型循环管路实验平台,实验研究了自来水、乙二醇和26#白油分别在304不锈钢管、有机玻璃管、聚丙烯管(PP管)和聚四氟乙烯管(PTFE管)内层流流动的阻力特性。通过测量不同流量下的压降,计算得到了摩阻系数和泊肃叶数随雷诺数的变化关系以及相同雷诺数下摩阻系数随接触角的变化关系,同时采用接触角测定仪分别测量了3种液体在4种管道表面的接触角,讨论了管道表面润湿性对流动阻力的影响规律。实验结果均表明,管道表面润湿性对流动阻力产生了一定的影响:在相同雷诺数下,随着液体在管道表面接触角的增大,液体的泊肃叶数和摩阻系数均呈现减小的趋势;疏液管道表面润湿性对摩阻系数的影响大于亲液管道,并且在雷诺数较小时这种现象表现得更加明显。     

Surface characterization of hollow fiber membranes used in artificial kidney

The internal and external curved surfaces of polysulfone hollow fiber membranes were characterized by atomic force microscopy (AFM), contact angle measurement (CAM), and scanning electron microscopy (SEM) with the aim of improving the membrane surface properties for blood compatibility. Novel approaches were applied to evaluate a number of properties, including the roughness, pore size, nodule size, and wettability of the surfaces of the hollow fibers. CAM studies were carried out by directly observing the liquid meniscus at the surfaces of hollow fibers. Observation of the meniscus and measurement of the contact angle became possible by using an imaging system developed in our laboratory. AFM and SEM studies were also conducted on the surfaces of the hollow fiber membranes by cutting them at an inclined angle. The effect of the molecular weight of poly(ethylene glycol) (PEG) in the polymer blend on the surface properties of the hollow fibers was studied. Increasing the PEG molecular weight increased the average pore size whereas it decreased the contact angle. The contact angle depended on the microscopic surface morphology, including nodule size and roughness parameters. The theoretical prediction along with the experimental data showed that the measured contact angle would be greater than the value intrinsic to the membrane material because of the formation of composite surface structures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4386–4400, 2006     

纳米结晶纤维素表面修饰聚酰亚胺纤维及其润湿功能性

聚酰亚胺纤维在应用方面存在许多潜在问题，例如聚酰亚胺纤维的低表面活性，使得其界面的润湿性能差，且在水相中易团聚，分散性较差。为此，本文提出在复合路易斯酸及交联剂共同催化作用下，使纳米结晶纤维素（CNC）修饰碱处理后的聚酰亚胺（PI）短切纤维表面，测定了CNC修饰前后PI纤维在水溶液中的分散度及PI纤维成纸的接触角，结果表明PI纤维的浸润功能性得到提高。采用扫描电子显微镜（SEM）观察了纤维的微观形貌，利用傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）表征了纤维表面结构的变化，最后通过多孔材料孔径分析仪测定了纤维成纸的孔径分布变化。结果表明：经CNC处理后的纤维表面发生了酯化反应且存在交联现象，纤维表面氧元素物质分数增加，含氧极性基团和表面粗糙度的增加有助于改善润湿性能，与PI纤维原纸相比，经CNC表面修饰后的纤维所成的纸页与去离子水的接触角降低了14.9°，与乙醇的接触角降低了4.8°，纤维分散度增加了45％，纤维亲水性显著提高，经过表面处理后的纤维在水相体系中的分散性能得到改善。因此，本法可以作为制备高性能纤维和相应复合材料的有效方法。     

十四酸铜超疏水表面的溶剂热法制备及其润湿性

超疏水表面是防止低温条件下风机叶片表面结冰、保证机组安全运行的重要材料之一。本文以十四酸乙醇溶液和铜片为前体,基于溶剂热法将十四酸铜原位生长于铜片表面,通过调控前体浓度和反应时间获得了不同润湿性的疏水表面,实现了疏水表面润湿性的有效调控。此外,采用扫描电子显微镜（SEM）观察了十四酸铜团簇的微结构及分布状态;借助X射线衍射仪（XRD）验证团簇粉末的晶格成分;通过接触角测量仪量化不同条件下样品的表面润湿性。结果表明,随着铜片表面十四酸铜团簇密集程度的增加,液滴与铜片的接触角增大,铜片润湿性降低;十四酸乙醇溶液浓度及反应时间可以显著改变十四酸铜分布状态,进而改变表面润湿性。疏水表面润湿性的变化是由于Ostwald熟化促进晶体生长,使表面的“禾苗”状聚合物逐渐生长成十四酸铜微米花。     

Surface wettability of human hair. II. Effect of temperature on the deposition of polymers and surfactants

The effect of treatment temperature on the deposition and substantivity of surfactants and polymers on the surface of human hair has been investigated by measuring the surface wettability of the fiber with water before and after treatment. Advancing wettabilities indicate that the adsorption of low molecular weight cationic surfactants on the negatively charged hair surface goes through a maximum as treatment temperature is increased. This suggests an increase in the extent of chemisorption with increase in temperature, the decrease in wettability beyond the maximum being due, apparently, to orientation of the surfactant lipid chain toward the water making the surface more hydrophobic and less wettable. The adsorption and substantivity of anionic surfactants are low, due to the repulsion of negative charges on the hair surface. As with cationic surfactants, the adsorption of cationic polymers increases with treatment temperature, suggesting an increase in adsorption site activation. Increase in treatment temperature also increases polymer substantivity due to a lower probability of desorption resulting from multiplicity of attachments to sites on the fiber surface. Oxidation of the hair fiber surface, which involves disulfide cleavage to produce charged sites, leads to an increase in the extent of surface coverage and substantivity especially at lower treatment temperatures; reduction, on the other hand, does not result in significant increases. In those cases where desorption of deposited material does not affect the surface tension of the measuring liquid drastically, wettability data can be used to determine an average surface coverage if the contact angle of the liquid on the pure treatment material is known.     

阳极氧化处理对碳纤维强度离散性的影响及表征

采用阳极氧化法对碳纤维进行了表面处理,并探讨了表面处理后碳纤维接触角、强度的变化和碳纤维强度离散性的表征方法。研究发现:碳纤维在阳极氧化表面处理后,接触角变小,说明浸润性增强,强度略有下降,离散性略有增大;表面处理后随放置时间延长,接触角有一定程度增大,强度继续下降,离散性继续增大。用强度CV值和韦伯分布拟合强度所得的韦伯模数两种不同指标表征了表面处理后碳纤维的强度离散性,经验证,两种表征方法的一致性好。     

Evaluation of fiber wettability based on an immerging force measurement

This article provides a new approach to estimate the wettability of fibers based on the force analysis in immerging procedure. A fiber in horizontal is forced into and withdrawn from the liquid at a certain speed, and the force changes are detected simultaneously. The experimental results show that the force impulse can be found at fiber contacting with liquid and immersed into liquid, and its value depends on the wettability of the fiber. According to the force impulses of different fibers, the immerging behavior of the fibers can be obtained and categorized into four characteristics. Meanwhile, the wettability of the fibers can be evaluated with the wettability factor, w, derived from the fiber immerging curve, where w is the ratio of the force increment on fiber initially contacting with the liquid to the force increment on liquid surface closing with fiber immerging into the liquid, and with the contact angle, θ, calculated from the wettability factor (θ = π/(w+1)) supposed that the fiber is a circular cross section. The pulling‐out test for a fiber has also been conducted and the results are discussed briefly in this article. The force measurement indicates that the method can be used for various fibers with short length, or lower density than that of the liquid, or poor wettability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2659–2666, 2006     

气液过滤过程中液滴二次夹带现象分析

在天然气长距离输送过程中,天然气夹带的液滴严重影响压缩机组的安全可靠运行。利用所建立的滤芯过滤性能检测装置,以癸二酸二辛酯为实验介质,分析了天然气净化用滤芯气液过滤过程中液滴二次夹带现象的特征,比较了滤材润湿性和过滤速度等参数的影响。结果表明:当滤芯仅由聚结层组成时,滤芯过滤过程中存在液滴二次夹带现象,二次夹带将导致下游气体中液滴数量增多,且有较大液滴出现,稳态阶段滤芯累积效率在大粒径处下降;液滴在滤材表面的润湿性对二次夹带现象具有重要影响,可润湿型滤材表面更易出现液滴二次夹带现象,在相同过滤速度下,若需提高过滤效率,宜选用不可润湿型滤材制作工业滤芯;在0.1～0.3 m·s^-1过滤速度范围内,提高过滤速度可减少液滴二次夹带现象的发生,与不可润湿型滤芯相比,可润湿型滤芯过滤效果的改善更为明显;滤芯增加排液层可有效消除液滴二次夹带现象。     

防指纹涂层实验室评价方法研究

建立防指纹（ Anti-fingerprint,AF）涂层实验室评价方法是研制开发手机屏和手机膜 AF涂层的基础。文中提出了通过测定水在手机膜表面的接触角反映汗液中主要成分水在手机膜表面的润湿程度,并通过绘制润湿性包络图表征汗液中其他成分在手机膜表面的润湿程度来研究液体在固体表面的润湿性与固体表面能的关系。在此基础上,设计了一种基于 Young-Laplace方程拟合分析蒸馏水和二碘甲烷在手机膜表面的接触角,利用 Owens-Wendt-Kaelble公式得出被测样品的表面能参数,绘制润湿性包络图并采用面积法求取包络图面积 S,评价表面被液体润湿能力的方法。结合水在手机膜表面的接触角数值,综合分析手机膜的防指纹效果。通过实验分析了 3种手机膜的防指纹效果,结果表明所设计的评价方法能够合理地反映手机膜的防指纹效果。     

Laser scanning confocal microscope characterization of dye diffusion in nylon 6 fibers treated with atmospheric pressure plasmas

The effect of atmospheric pressure plasma treatment on wettability and dyeability of nylon 6 fibers is investigated. The plasma treatments resulted in an average of 10°–20° decrease in the advancing contact angle and 20°–30° decrease in the receding contact angle. An increased dye diffusion rate of nylon 6 fibers was observed using laser scanning confocal microscope (LSCM). Scanning electron microscope confirmed that the fiber surfaces were roughened, and X‐ray photoelectron spectroscopy showed that the polar groups on the fiber surfaces increased after the plasma treatments. As the plasma treatment time increased, a greater degree of etching was achieved and more polar groups such as hydroxyl and carboxyl groups produced on the surfaces of the nylon 6 fibers, leading to a better wettability and thus a better dyeability of the fiber. This study proved that LSCM may be effectively used in detecting the change of dye diffusion rate in nylon fibers treated with plasmas and the mounting medium should have a close refractive index as the fiber to avoid distortion of the fiber cross section image. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Novel superhydrophobic top coating on surface modified PVC-coated fabric

A superhydrophobic surface was created on poly(vinylchloride)-coated architectural fabric using spray coating method. Dispersions of nanoparticles and a flourochemical were prepared as top coating solutions. After spray-dry-cure process, contact angle, sliding (tilt) angle, 3 M water repellency test and surface morphology were compared between uncoated and top coated PVC surfaces. The results indicated that a specific nano-TiO₂ dispersion top coating produced a superhydrophobic layer on the top of the PVC surface with high contact angle (150°) and very low sliding angle (2°). Combination of two major requirements, the magnified of the degree of roughness and low surface energy, created self-cleaning effect on the PVC surface. Abrasion fastness of superhydrophobic top coating was improved by surface oxidation via UV–ozone surface treatments. Spectroscopic analysis demonstrated that formation of oxygenated functional groups has improved PVC wettability and adhesion. Results of artificial weathering test indicated no change in superhydrophobicity of top coated PVC.