云南混合型胶磷矿正浮选浮选行为与机理研究

对云南混合型胶磷矿中的磷矿物、白云石和硅质矿物进行了浮选速率试验和接触角等机理研究,结果表明:当浮选时间超过2 min后,浮选过程为无效选矿;延长浮选时间虽然可以提高精矿回收率,但会降低精矿品位.利用白云石矿物、磷矿物和硅质矿物在一定浮选时间内浮选速率的高低可以确定脱除脉石矿物的浮选工艺,即先混合浮出磷矿物和白云石矿物...     

有机液体在粉末上接触角的测定研究

得到了一系列有机液体在粉末上的接触角的数值和表面活性剂在这些粉末上表现的性质,并做了定性和定量分析。实验原理建立在把渗透的液体进入玻璃管内粉末形成的多孔塞基础上,将Washburn方程用于毛细管内液体的流动用于计算液体和粉末之间接触角大小。结果显示了有机液体分子在石墨、铝粉上表面吸附的细节,并讨论其在科研和生产实践中的应用。     

粉体接触角的测定方法

本文介绍了薄板毛细渗透技术测定粉体表面接触角和粉体表面能的理论基础、实验方法及其新进展,与传统的透过法相比,该法测得的接触角数据相对准确,而且基于不同探针液体的接触角获得的粉体表面能的成分彼此一致。     

高度法和压力法测定粉末接触角的比较

粉体接触角的测定有着十分重要的理论和实际应用意义。根据Washburn方程,在渗透法测定粉末接触角的基础上,引入相对接触角的概念,并设计了测定石墨粉相对接触角的试验装置,以苯作为参比液,用高度法和压力法分别测定了25℃下蒸馏水对石墨粉的相对接触角,它们分别为83.50°和83.74°。试验结果表明,压力法和高度法均可用于粉末接触角的测定。     

活性CaCO3粉末表面性能研究

用四种表面处理剂对ＣａＣＯ３浆液进行表面处理，并根据Ｗａｓｈｂｕｒｎ方程，通过测定活性ＣａＣＯ３粉末的润湿性，研究其表面性能，借此确定其表面处理单分子层处理量     

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。     

粉体接触角法快速测定长江口沉积物的表面自由焓变

根据Washburn原理研制的JF99A型粉体接触角测量仪,是利用渗透压力法测定粉体的接触角。在室温下,采用去离子水、无水乙醇、5％（m／m）的NaCl溶液、15％（V／V）的乙醇溶液为润湿液体．测定了长江口南港白龙港水域沉积物的相对接触角,从而可以确定沉积物的表面自由焓变。测定沉积物表面的润湿性疏水性质,就能反映表面上是否存在有机污染。用此方法测定具有操作简单等优点。     

纤维接触角测定方法研究

介绍了两种常用的纤维接触角测定方法。采用喷雾法测试纤维接触角时,喷雾方式应优选斜喷。采用润湿天平法测试纤维接触角时,纤维露出夹子长度的最佳值为1mm。润湿天平法测得数据重现性较好,但操作较为烦琐,且不适合测试棉、涤纶等刚性较小、易弯曲纤维的接触角;喷雾法操作简单,适合测试各种纤维的接触角。     

磷矿浮选碳酸盐抑制剂应用研究

YY1是一种碳酸盐矿物抑制剂,在磷矿浮选中添加YY1后,正浮尾矿MgO质量分数从2.31%上升到18.23%.尾矿中MgO回收率从8.86%提高到46.88%,而精矿中MgO回收率从91.120%降至53.11%,说明YY1对白云石等碳酸盐有明显抑制效果,文中还对YY1的作用机理进行了探讨.     

液滴形状法测量纤维接触角的研究

介绍了液滴形状法测量单根纤维接触角的基本原理 ,利用显微镜观察液滴的形状 ,将数据输入根据Young Laplace方程编写的程序中计算出接触角。通过实验验证 ,该法简单可行 ,可以有效的表征 0～ 60°的纤维表面接触角。     

Perturbation solutions to the sessile drop profile equation and their application to contact angle determination

By employing perturbation theory, first-order and second-order approximate solutions have been obtained for the analytically insoluble second-order differential equation describing the profile of an axisymmetric sessile drop. These solutions can be of practical value in the determination of contact angles (90°) from the diameter and height of sessile drops. The drops in question may be relatively large (eg for water, diameter up to about 15 mm) and thus the solutions may be considered as useful extensions of formulae for contact angle assuming drop sphericity.     

On the use of Washburn's equation for contact angle determination

A systematic study on the possibility of Young's contact angle determination from Washburn's equation was performed using the so-called thin-layer wicking technique in which the rate of penetration of a liquid into the porous layer of a solid is measured. Commercial (Merck) SiO₂ deposited on the glass plate for thin-layer chromatography was used as a model solid and n-alkanes (from pentane to hexadecane), diiodomethane, and α-bromonaphthalene were employed as the probe liquids. It was shown that the contact angle calculated from Washburn's equation was not equal to Young's contact angle of a drop of the same liquid, placed on a flat surface of the solid. Consequently, the solid surface free energy components calculated using contact angles from Washburn's equation are not the true values. However, the approach previously suggested by us has been verified again, as it gives consistent values of the surface free energy components determined from all the liquids used.     

New method of determining contact angle between monofilament and liquid

This paper describes a method to obtain contact angle by observing the shape of a liquid drop attached to a monofilament. The relations between contact angle and the dimensions of drops are theoretically obtained. Thus, it is possible to calculate the contact angle if drop shape is measured. Through use of this method, the contact angles of epoxy resin on various kinds of monofilaments were measured. It was found that this method has practical utility for measurement of the contact angle between liquid and monofilament.     

利用TEM鉴定爽身粉中石棉方法的研究

利用透射电子显微镜对爽身粉进行观察,通过纤维形态、选区电子衍射谱和能谱可以判断试样中石棉的存在,并可判断石棉类型.该方法用于爽身粉中石棉的鉴定得到满意的结果.     

Comparative study of surface properties determination of colored pearl-oyster-shell-derived filler using inverse gas chromatography method and contact angle measurements

Mollusk shells, such as clam, mussel, oyster and pearl oyster shells, are potential candidates for commercial calcium carbonate-based fillers. In this work, the surface properties of colored pearl-oyster-shell-derived filler (CMF) were investigated with comparison to those of pearl oyster shell powder (MSP), using an inverse gas chromatography (IGC) method and contact angle measurements. A developed computational model for the interpretation of surface free energy heterogeneity distributions was applied to both samples. The contact angle measurements revealed an amphiphilic nature. The dispersion component of surface free energy for both samples calculated using the Owens–Wendt–Kaelble (OWK), van Oss–Chaudhury–Good (vOCG) and Wu methods were consistent with those determined using the IGC method. The deconvolution of surface energetic sites confirmed their energetic heterogeneity. The CMF displayed lower work of cohesion, which could be beneficial to the fabrication of polymer composites, as typically reduced filler particle-particle interactions would result.     

Uncertainty in contact angle measurements from the tangent method

The uncertainty in contact angles from sessile drops measured by the tangent method was estimated using a standard error propagation technique involving partial derivatives. If contact angles are <60°, then uncertainty of the tangent method appears to be quite small,≤ ± 2°. However, as θ values approach 90°, uncertainty increases asymptotically and can exceed ±5°.     

用接触角法估算复合材料的表(界)面特性

采用填料柱法测量了不同表面处理的导电炭黑的接触角,并根据联立的粘合理论估算了炭黑填充低密度聚乙烯导电复合材料的表（界）面特性参数。实验结果表明,硝酸处理使炭黑的表面自由能、界面粘附功有所提高,而偶联剂处理则结果相反;炭黑表面羧基含量的改变是影响炭黑表（界）面性质的主要原因。正是由于炭黑表（界）面性质的这种改变,从而调节了炭黑－低密度聚乙烯的界面相互作用,导致炭黑在聚乙烯基体中的分散形态发生了相应的     

工业级二水合磷酸二氢钠含量测定方法的研究

提出了用电位法测定工业二水合磷酸二氢钠含量.电位法是利用校准过的酸度计,用氢氧化钠标准溶液滴定至试样溶液pH为9.3.并且采用重量法、中和法与电位法进行比对.结果表明,用电位法测定工业二水合磷酸二氢钠含量操作简单、快捷、准确,且稳定性好.