水处理滤料表面润湿性及表面自由能与其亲油亲水性关系的研究

本实验首先利用钛酸酯DN-101和铝酸酯DL-411对石英砂滤料进行改性,然后选择未改性石英砂、DN-101改性石英砂和DL-411改性石英砂滤料作为研究对象来研究其润湿性和表面自由能同亲油亲水性之间的关系;同时以正己烷和去离子水作为探针液。用毛细重力法对水相去离子水及油相环己烷进行润湿,来探究各种滤料的亲油亲水性。结果表明未改性石英砂亲油亲水比(LHR)仅为0.823,亲油性较差,DN-101改性石英砂亲油亲水比(LHR)高达46.58,具有较强的亲油性,而DL-411改性石英砂亲油亲水比(LHR)为4.95,表现出一定的亲油性。并且通过XPS图谱分析了各滤料表面化学成分,结果表明DN-101改性石英砂表面自由能较弱,对油相有较好的润湿,表现出较好的亲油性,而未改性石英砂表面自由能较强,亲油性较差。DL-411改性石英砂趋于两者之间。     

水处理滤料润湿性能测定方法的比较研究

根据Washburn方程,采用高度法和压力法测量滤料接触角,引入亲油亲水比(RLH)的概念,以正辛醇和去离子水作参比液,得出了25℃下核桃壳和石英砂滤料的亲水亲油比值。结果表明,压力法更适合滤料接触角测量,核桃壳颗粒对于非极性液体的润湿性较好,石英砂对于极性液体的润湿性较好,本研究为含油废水处理滤料的润湿性能改进提供一种新思路。     

RDX表面能及其分量的测定

采用Washburn薄层毛细渗透技术测定了RDX粉体的接触角和表面能及其色散、极化、电子受供体分量.选用非极性的二碘甲烷和1-溴萘作为测定RDX表面能色散分量的探针液体,极性的乙二醇和甲酰胺作为测定RDX表面能极性分量和酸、碱分量的探针液体.通过测定不同探针液体的渗透曲线,发现基于不同探针液体分子的接触角获得的RDX粉体的表面能成分彼此一致,RDX的总表面能(40.20 mJ · m-2)与理论计算结果(40.60 mJ · m-2)基本一致.测得的色散分量为23.71 mJ · m-2,极性分量为16.49 mJ · m-2,电子受体分量为1.149 mJ · m-2,电子供体分量为51.87 mJ · m-2.结果表明,在RDX的表面能中,色散分量占主要部分,而且在极性分量中电子供体碱性分量明显大于电子受体酸性分量.     

微波辐射对硫酸钙粉末表面能影响的研究

为了探索微波对固态物质表面的影响作用,并对化工表面过程引入微波强化提供依据,根据Washburn浸溃理论和Owens-Wendt-Kaelble法及薄板毛细渗透技术,采用了多种有机物作为液体探针,测定了微波辐射下硫酸钙粉末的接触角变化和表面自由能.测定结果显示微波辐射后硫酸钙粉末的表面自由能得到提高,从39.6mJ·-2增加到41.8mJ·m-2,其主要原因是使硫酸钙表面能的极性成分得到了较大的提高.这一结果归于微波幅射引起晶粒表面的电荷重排,与晶粒表面能带分裂引起的电子跃迁理论是相吻合的.     

温度对杨木木粉表面自由能和表面极性的影响

通过毛细管上升法测定了经过不同温度处理的杨木木粉的表面接触角,依据Washburn方程和Owens-wendt-Kaelble法,求解了经过不同温度处理的杨木木粉的表面自由能及其极性分量和非极性分量。结果表明,杨木木粉的表面自由能为23.43 mN/m,体现分子色散力的非极性分量为4.64 mN/m,在处理时间为2 h的条件下,随着处理温度的上升,杨木木粉的总表面自由能略有下降,体现其分子色散力的非极性表面自由能上升,体现其表面极性值的极性表面自由能下降,并分析了上述结果的原因。     

巩义市涉村韵山水处理材料厂

正巩义市涉村韵山水处理材料厂是国内最早生产净水材料和钢制、橡胶管件的专业厂家之一。专业从事研发、生产、销售水处理系列产品。产品有四大系列共一百多个品种,主要包括:纤维滤料系列慧星式纤维滤料、高效纤维束滤料、高效纤维球滤料、改性纤维球滤料净水滤料系列HXT-系列活性炭、HXT-20净水化用活性炭、HXT-20系列果壳活性炭、HXT-30系列粉状活性炭、HXT-40系列煤质活性炭、精制无烟煤滤料、页岩陶粒、焦炭滤料、精制石英砂滤料、普通石英砂滤料、火山岩生物滤料、果壳滤料、承托层(鹅卵石、石英砾石)滤料、锰砂滤料(除铁锰砂)、蛇纹石、稀土瓷砂滤料、磁铁矿滤料、海绵铁滤料(除氧剂)、陶粒滤料、生物陶粒滤料、活性氧化铝、金刚砂滤料、麦饭石滤料、石榴石滤料、沸石滤料、泡沫滤珠滤料、海绿石滤料、滤砖     

使用反相气相色谱法表征合成纤维表面润湿性

以聚丙烯纤维、聚癸二酰己二胺纤维和聚对苯二甲酸乙二醇酯纤维为研究对象,使用反相气相色谱法,以含有不同碳数的正烷烃和蒸馏水为探针分子,分别测定了合成纤维的表面自由能色散分量和水分子的净保留体积,表征其表面润湿性并分析影响因素。结果表明,纤维化学结构单元是合成纤维表面润湿性的决定性因素：具有非极性基团的聚丙烯纤维亲油性较好,具有极性基团的聚癸二酰己二胺纤维亲水性较好;纱线的线体结构影响合成纤维受热时的膨胀程度,从而显著影响表面自由能色散分量随温度的变化趋势。     

滤料表面电动电位的研究

根据流动电位与表面ξ电位的关系研制了一套测定滤料表面ζ电位的装置,经测定计算出了常用六种水处理滤料的表面ζ电位。结果表明:磁铁矿、沸石、石英砂、陶粒砂、核桃壳、无烟煤表面ζ电位分别为-60.85mV、-25.45mV、-24.37 mV、-21.49 mV、-14.24mV、-14.17mV。用红外光谱分析说明了各种滤料表面ζ电位存在差异的原理。     

表面自由能差对乙醇-水混合蒸气冷凝传热特征的影响

实验研究了常压下不同浓度的乙醇-水混合蒸气的冷凝传热过程.发现在不同的乙醇含量和过冷度条件下,冷凝形态呈现膜状、过渡态和滴状的变化.相应传热系数也发生变化.基于该冷凝过程实质为薄液膜表面上的冷凝过程,以及蒸气冷凝传热系数随表面自由能差渐进变化的机理,首先确定了其表面自由能差为液-液表面自由能差,并以此解释了乙醇-水混合蒸气冷凝过程传热特性的变化规律.研究表明,随着冷凝液与薄液膜二者的表面自由能差的增大,冷凝传热系数逐渐增大,并且冷凝形态发生变化,当表面自由能差小于(14±1)mJ·m-2时为膜状冷凝,大于(21±1)mJ·m-2时为滴状冷凝,介于二者之间时为过渡状态.     

表面自由能对陶瓷釉面易洁性的影响

用接触角测试法研究表面自由能对陶瓷釉面易洁性的影响.用Dataphysics OCA-30接触角测试系统中的动态接触角记录功能测试水中模拟污物油酸在陶瓷釉面上的动态行为.用座滴法测试不同陶瓷釉面的表面自由能及其组成.用悬滴法测试油酸的表面张力及其组成.结果表明:陶瓷制品表面自由能极性分量所占比例越大,表面自由能越高,水中油酸在陶瓷釉面上的黏附趋势也越小,陶瓷釉面的易洁性越好.当陶瓷釉面极性分量达到46.17mJ/m2,占表面自由能85.91%时,水中油酸在此釉面上的黏附功为2.11 mJ/m2,油酸在98 s后可自动浮起.     

Capillary pressure method for measuring lipophilic hydrophilic ratio of filter media

Lipophilic Hydrophilic Ratio (LHR) was defined based on Washburn equation. The LHR values of five filter media were calculated from the wetting rates of cyclohexane (apolar) and water (polar) through compact filter media beds measured by capillary pressure method. The surface structures of filter media were characterized by X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). It was confirmed by great regression coefficients and reproducibility of wetting rates that the values have a good reliability and the technique is applicable. The LHR values of nutshell, manganese sand, ceramic granule, quartz sand and ceramic sand are 66.87, 1.24, 1.22, 1.16 and 0.80, respectively, which shows that nutshell is much more lipophilic while manganese sand, ceramic granule and quartz sand are somehow more lipophilic than ceramic sand. This fact is consistent with the results of XPS and FTIR.     

Wettability studies of filter media using capillary rise test

Filtration process is a typical tertiary treatment method for oily wastewater, suitable for the lower oil concentration and oil-in-water emulsion system. Therein the wettability of oil-in-water emulsions to filter media probably has some significant influences on the oil removal efficiency, namely a lipophilic filter medium have a better performance in oil droplets coalescence and attachment than a hydrophilic one. In this paper, a Lipophilic to Hydrophilic Ratio (LHR) concept was defined on the basis of Washburn's equation and a test equipment was correspondingly designed, which were used to compare quantificationally the wettable selectivities of three filter media to oil and water. The selected filters were anthracite, manganese ore and quartz sand particles with a size fraction of +0.9 to 1.2 mm and the wetting liquids were apolar cyclohexane and polar deionized water. At the same time, the effect of filter particle size on the LHR value was also explored. Linear least-square fits for all wetting rates gave regression coefficients of more than 0.9991, confirming the suitability of the experimental method for filter particles and further validating Washburn's theory. The determined LHR values of anthracite, manganese ore and quartz sand are 1.93, 0.75 and 0.69, respectively, which means anthracite is lipophilic while manganese ore and quartz sand are hydrophilic. Moreover, for three selected particle size fractions the LHR values of anthracite particles are always the greatest and that of manganese ore are a little bit greater than quartz sand particles. Therefore, it can be deduced that the wettable differences probably be attributed to the differences of surface chemistries of filter samples. Namely, anthracite surface contains principally organic functional groups composed of carbon and oxygen elements and therefore presents apolar and lipophilic characterization, while manganese ore and quartz sand surfaces have SiO₂ species and make them polar and hydrophilic. This conclusion is approximatively confirmed by the analysis results of X-ray photoelectron spectroscopy (XPS).     

石英砂滤料表面干法改性制备疏水性除油滤料

采用钛酸酯偶联剂DN101对石英砂滤料进行表面干法改性,增强滤料的亲油疏水性。通过单因素实验研究改性时间、DN101浓度以及改性温度对改性效果的影响,并以亲油亲水比LHR作为评判改性效果的标准。结果表明,反应时间为70 min、DN101用量为1.2%、反应温度为60℃时,DN101干法改性石英砂效果最好,LHR值由未改性时的1.25提高到最大值11.1;改性石英砂对15.61 mg·L^-1含油废水的吸附容量由未改性时的0.17 mg·g^-1增大到0.25 mg·g^-1;对17.3 mg·L^-1含油废水的过滤去除率由未改性时的72.6%提高到97.8%。扫描电镜、电子能谱和红外光谱分析结果表明,DN101以化学键的方式与石英砂表面官能团结合,对石英砂形成了均匀稳定的包覆层。     

氧化铁改性石英砂过滤性能及反冲洗效果研究

对自制涂铁砂进行过滤和反冲洗试验,研究不同滤层(每层为12 cm)的截污性能,并与原始石英砂和活性炭-涂铁砂组合滤料的性能进行对比研究,探讨涂铁砂对浊度和有机物的过滤效果及其再生能力。结果表明,(1)涂铁砂存在一个使用成熟期,约3个工作周期。成熟期后,其对浊度和有机物的去除率最高,为96.5%、75.4%。(2)涂铁砂对浊度的有效截污滤层集中在前2层,总去除率为88.73%。(3)经相同强度气水反冲洗后,涂铁砂滤层厚增加幅度最大(为5 cm),过滤周期为石英砂的1.5倍。(4)改进后的气水反冲洗强度为:气冲4 min,q气=12L.m-.2s-1;气水同时冲5 min,q气=12 L.m-.2s-1,qNaOH=10 L.m-2.s-1,NaOH=0.1 mol.L-1;清水漂洗3 min,q水=10 L.m-2.s-1。(5)反冲洗后,活性炭-涂铁砂组合滤料中涂铁砂表面的块状及针状形态学特征不变,对有机物的去除效果保持不变,为74.1%。     

等离子体处理对芳纶性能的影响

芳纶作为增强材料在复合材料中有广泛的应用,其界面性能是影响其复合材料界面粘结性能的重要因素。分别采用H2、空气低温等离子体对芳纶表面进行了处理。研究了等离子体表面改性后芳纶性能的变化。结果表明:经低温等离子体处理后纤维表面张力增大,由46.0mN·m-1增加到63.2mN·m-1;表面极性增强,极性分数由58.0%提高到69.9%,而纤维单丝断裂强度未有明显变化。     

用石英砂替代标准无烟煤测定粘结指数的研究

通过改变石英砂掺比后的粘结指数试验表明随着石英砂掺入比例的减少试验煤样的似粘结指数逐渐增加,以石英砂为添加物的混焦似粘结指数与混焦粘结指数二者的比值同配合比具有非常好的线性回归关系,在此回归方程的基础上,建立了混焦粘结指数同不同比例下以石英砂为添加物的混焦的似粘结指数之间的相关方程。补充试验表明以标准无烟煤为添加物的混焦似粘结指数随配合比先增加后减小,当配合比小到1:5以后时,混焦的似粘结指数几乎和不添加添加物的全混焦的似粘结指数相当。通过比较不同添加物不同配比下混焦似粘结指数得出同配合比下以标准无烟煤为添加物的混焦似粘结指数大于以石英砂为添加物的混焦似粘结指数,二者之间的差别随配合比增大而增大。非线性回归结果表明以标准无烟煤为添加物的混焦似粘结指数(G_(2a)′)与以石英砂为添加物的混焦似粘结指数(G_(2s)′)的比值与配合比具有非常好的拟合关系。     

Effect of woody biomass surface free energy on the mechanical properties and interface of wood/polypropylene composites

The aim of this study is to investigate the effect of surface free energy of wood flour (WF) and silanized WF on the mechanical properties and interface of wood/polypropylene (PP) composites. The contact angles of three probe liquids against unmodified and modified spruce WF were tested by capillary rise method based on the Washburn equation. Then the surface free energy and its corresponding dispersion and polar components were calculated according to the method developed by Owens–Wendt–Kaelble. The tensile strength and flexural strength of the wood/PP composite samples made with unmodified and modified WF were tested and the flexural fracture surfaces were analyzed by scanning electron microscopy (SEM). The results showed that the surface free energy of WF increased from 26.0 to 36.1?mJ/m², which was higher than that of PP (29.4?mJ/m²), and its corresponding polar component decreased from 13.1 to 4.4?mJ/m², and the dispersion component increased from 12.9 to 31.7?mJ/m² after the modification with 4 wt.% vinyltriethoxy silane, which makes it possible for spreading of PP on the surface of WF, the tensile strength and flexural strength of wood/PP composites made with modified WF were obviously improved. In addition, the improved compatibility between WF and PP was well confirmed by SEM.     

A new model to determine contact angles on swelling polymer particles by the column wicking method

The contact angle determination on swelling polymer particles by the Washburn equation using column wicking measurements may be problematic because swelling occurs during the wicking process. The objective of this research was to develop a new model to more accurately determine contact angles for polymer particles that undergo solvent swelling during the column wicking process. Two phenomena were observed related to the swelling effect during the wicking process: (1) a temperature rise was detected during the wicking process when the swelling polymer particles interacted with polar liquids, and (2) a smaller average capillary radius (r) was obtained when using methanol (polar liquid) compared to using hexane (non-polar liquid). The particle swelling will induce both particle geometry changes and energy loss which will influence the capillary rise rate. The model developed in this study considered the average pore radius change and the energy loss due to the polymer swelling effect. Contact angle comparisons were conducted on wood with formamide, ethylene glycol, and water as test liquids, determined by both the new model and the Washburn equation. It was shown that the contact angles determined by the new model were about 4-37° lower than those determined by the Washburn equation for water, formamide, and ethylene glycol. Todetermine whether the polymer particles are swelling, two low surface tension liquids, one polar (methanol) and the other non-polar (hexane), can be used to determine the average pore radius (r values) using the Washburn equation. If the same r values are obtained for the two liquids, no swelling occurs, and the Washburn equation can be used for the contact angle calculation. Otherwise, the model established in this study should be used for contact angle determination.     

Studies on surface energetics of glass fabrics in an unsaturated polyester matrix system: Effect of sizing treatment on glass fabrics

The surfaces of glass fibers were sized by polyvinyl alcohol (PVA), polyester, and epoxy resin types in order to improve the mechanical interfacial properties of fibers in the unsaturated polyester matrix. The surface energetics of the glass fibers sized were investigated in terms of contact angle measurements using the wicking method based on the Washburn equation, with deionized water and diiodomethane as the wetting liquids. In addition, the mechanical behaviors of the composites were studied in the context of the interlaminar shear strength (ILSS), critical stress intensity factor (K_IC), and flexural measurements. Different evolutions of the London dispersive and specific (or polar) components of the surface free energy of glass fibers were observed after different sizing treatments. The experimental result of the total surface free energies calculated from the sum of their two components showed the highest value in the epoxy‐sized glass fibers. From the measurements of mechanical properties of composites, it was observed that the sizing treatment on fibers could improve the fiber–matrix interfacial adhesion, resulting in improved final mechanical behaviors, a result of the effect of the enhanced total surface free energy of glass fibers in a composite system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1439–1445, 2001