双子两性磷酸酯/十二烷基硫酸钠复配体系的表面活性

研究了阴离子表面活性剂十二烷基硫酸钠(SDS)和双子两性磷酸酯表面活性剂(C12GP)的形成胶束能力和降低表面张力能力的协同作用,发现C12GP与SDS摩尔比为4∶1时增效作用显著.考察了无机盐、醇对复配体系表面活性的影响.结果表明:加盐能够提高表面活性;短链脂肪醇作为添加剂应用于复配体系后,当混合表面活性剂的浓度较低时,其临界胶束浓度(ccm)比直接使用混合表面活性剂的ccm有所下降;同时长链脂肪醇作为添加剂应用于复配体系后,其ccm比直接使用混合表面活性剂的ccm下降显著.     

烷基糖苷-十二烷基甜菜碱复配性能及无机盐的影响

考察了非离子型表面活性剂烷基糖苷(APG)和两性表面活性剂十二烷基甜菜碱(BS-12)之间的复配性能,测定了不同摩尔比的APG和BS-12复配体系的表面张力、泡沫和乳化性能,并且研究了无机盐对复配体系表面活性的影响。结果表明,与单独任一表面活性剂体系相比,APG和BS-12复配体系具有较好的表面活性,呈现明显的协同增效作用;在摩尔比为3∶7时,复配体系的表面活性最高、起泡性能最好、形成的泡沫和乳状液最稳定,协同增效作用最显著。此外,无机盐的加入提高了复配体系的表面活性,当NaCl浓度为0.03 mol·L-1时,表面张力和临界胶束浓度最小,表面活性最高;而对于无机盐,其离子价态越高,提高表面活性程度越明显;相比之下,阳离子提高复配体系表面活性的能力大于阴离子。     

AES、SDS及复配溶液对镍污染土壤的淋洗研究

以阴离子表面活性剂脂肪醇聚氧乙烯醚硫酸钠(AES)、十二烷基硫酸钠(SDS)溶液及其复配液为土壤淋洗剂,研究比较对模拟镍污染黄壤粘土的淋洗去除效果。结果表明,适宜复配溶液为SDS∶AES=4∶6(质量比);AES在40℃、质量浓度为2.5%、pH值为4、土水比1∶30条件下洗脱效果最佳,镍去除率可达82.84%,SDS∶AES=4∶6复配溶液与SDS去除效果稍弱于AES,去离子水效果最差;各表面活性剂溶液淋洗过程动力学模拟结果均符合准二级动力学方程。     

AES、SDS及复配溶液对镍污染土壤的淋洗研究

以阴离子表面活性剂脂肪醇聚氧乙烯醚硫酸钠(AES)、十二烷基硫酸钠(SDS)溶液及其复配液为土壤淋洗剂,研究比较对模拟镍污染黄壤粘土的淋洗去除效果。结果表明,适宜复配溶液为SDS∶AES=4∶6(质量比);AES在40℃、质量浓度为2.5%、pH值为4、土水比1∶30条件下洗脱效果最佳,镍去除率可达82.84%,SDS∶AES=4∶6复配溶液与SDS去除效果稍弱于AES,去离子水效果最差;各表面活性剂溶液淋洗过程动力学模拟结果均符合准二级动力学方程。     

复配表面活性剂对浸渍银浆分散性能的影响

为了改善银粒子在浆料中的分散稳定性,选用阴离子表面活性剂十二烷基苯磺酸钠(SDS)与非离子表面活性剂聚乙烯醇(PVA)、甲基纤维素、明胶、油酸复配体系,考察表面活性剂种类及配比对浸渍银浆分散性能的影响,并探究其分散机理。运用分光光度计和SEM,分析了银粉在浆料中的分散稳定性和微观组织形貌。结果表明:阴-非离子复配体系能增强浸渍银浆分散稳定性。其中,SDS-PVA复配体系m(SDS)∶m(PVA)=4∶1的分散稳定性最佳,15 h内的沉降率RSH提升19%。     

Gemini双季铵盐表面活性剂与SDBS和SDS的复配行为

采用荧光分光光度法和Zeta电位法考察了系列Gemini双季铵盐表面活性剂与阴离子表面活性剂十二烷基苯磺酸钠(SDBS)和十二烷基磺酸钠(SDS)的复配效果。结果表明,Gemini双季铵盐表面活性剂疏水链和连接基越长,cmc越小,且疏水链长度对表面活性剂性能的影响较大;Gemini双季铵盐表面活性剂的加入可显著提高阴离子表面活性剂SDBS和SDS的表面活性,当Gemini双季铵盐表面活性剂与SDBS或SDS的摩尔比为3:7时,复配体系的cmc最小,且与SDS复配体系的性能优于与SDBS的复配体系。     

复配表面活性剂对铜CMP后清洗中颗粒的去除

选用阴离子表面活性剂脂肪醇聚氧乙烯醚硫酸钠(AES,体积分数0.1％)和非离子表面活性剂异辛醇聚氧乙烯醚(JFC-E,体积分数0.25％)复配的清洗液(pH=10.3)去除铜布线化学机械抛光(CMP)后表面残留的SiO2颗粒.研究了2种表面活性剂的体积比对复配溶液的润湿性能、在铜表面的吸附情况、清洗效果和对清洗后铜表面状态的影响.结果表明,按AES和JFC-E的体积比2:3复配的清洗液具有最佳的润湿性能和吸附效果,并且对颗粒的去除效果最好,对铜表面状态的影响最小.     

离子选择电极法分析非离子／阴离子表面活性剂体系

利用自制表面活性剂离子选择电极,采用电位滴定法测定了非离子表面活性剂脂肪醇聚氧乙烯醚(AEO9)与阴离子表面活性剂十二烷基硫酸钠(SDS)混合溶液中的SDS浓度。当AEO9与SDS的摩尔比约小于2∶1时,可用此种方法定量测定混合体系中的SDS的浓度,与滴定单一SDS溶液的结果对照,相对误差在1%以内。     

两性离子/阴离子表面活性剂复配体系协同作用的研究

研究了阴离子表面活性剂十二烷基硫酸钠(SDS)和两性离子表面活性剂月桂酰胺丙基甜菜碱(LMB)的形成胶束能力和降低表面张力能力的协同增效作用。发现SDS和LMB质量比在7:3至3:7范围内增效作用显著。并考察了无机盐对表面活性剂复配体系泡沫性能的影响,结果表明,低浓度的无机盐会使表面活性剂复配体系表面张力和CMC下降,发泡力上升,高浓度的无机盐会使表面活性剂复配体系发泡力下降。例如0.1mol/L的NaCl使0.0025%的复配体系表面张力下降1.73mN/m,0.17mol/L的NaCl使2%的复配体系泡沫高度上升7.2%,而NaCl浓度超过0.26mol/L后会使泡沫高度降低。     

一种含氟烷基磷酸酯类氟碳表面活性剂的复配研究

研究了含氟烷基磷酸单酯类表面活性剂[分子式为H(CF2)6CH2OPO(ONa)2,记为DFH-PS]与无机盐和普通碳氢表面活性剂的复配性能,研究结果表明,DFH-PS水溶液最低表面张力为23.73 mN/m;当NaCl浓度为0.2 mol/L时,可使DFH-PS水溶液最低表面张力下降到21.62 mN/m;阴离子碳氢表面活性剂十二烷基硫酸钠(SDS)对该含氟表面活性剂影响显著,当n(DFH-PS)∶n(SDS)=5∶1时,可使水溶液表面张力在很低浓度时降至22.22 mN/m;与非离子表面活性剂辛基酚聚氧乙烯(10)醚(OP-10)混合,当n(DFH-PS)∶n(OP-10)=8∶1时,可使水溶液表面张力降至27.0 mN/m。     

Synergistic effect of dodecyl sulfonate on apatite flotation with fatty acid collector

The synergistic effects between sodium dodecyl sulfonate (SDS) and a mixed fatty acids collector for apatite flotation were investigated. SDS benefitted the apatite flotation at pH 9.5. The TOC measurements showed that the addition of SDS improved the surfactants adsorption at the apatite surface. The colloidal size measurements suggested that the utilizing of SDS prevented the over-packing of fatty acids in the solution. Additionally, SDS did not adsorb/co-adsorb at the apatite surface as revealed by the FTIR and XPS results, because of the strong electrostatic repulsion between the apatite surface and the SDS ions.     

石墨烯/镍复合微结构表面的池沸腾传热特性

采用电刷镀和表面改性技术,在紫铜表面制备了纯镍微结构（TS1）、亲水性石墨烯/镍复合微结构（TS2）以及疏水性石墨烯/镍复合微结构（TS3）。采用扫描电镜和接触角测量仪分别对三类微结构的表面形貌和润湿性进行了表征;以去离子水为工质,对三类微结构表面的池沸腾传热特性进行了实验研究,发现含有石墨烯的TS2和TS3较TS1的沸腾传热性能均显著改善,其中,TS3具有最大的传热系数和最高的临界热流密度,与TS1相比,其最大传热系数和临界热流密度分别提高了135%和97%。分析表明,TS3具有复杂三维堆叠微结构,疏水性微结构减小了气泡成核的活化能,增加了核化密度,是传热系数提高的主要因素,同时,三维堆叠微结构增加了受热表面的毛细吸液再润湿能力,是临界热流密度提高的主要机理。     

明胶-阿拉伯树胶电子墨水微胶囊表界面控制

以明胶-阿拉伯树胶为壁材,四氯乙烯为分散介质,硬脂酸改性的TiO2为显示颗粒,采用复合凝聚法制备了红白显示的电子墨水微胶囊。讨论了表面活性剂十二烷基硫酸钠(SDS)对复合凝聚相生成过程的影响,并分析了Span 80用量对微胶囊形貌的影响。结果表明,SDS与明胶间形成的复合凝聚相具有很高的表面活性。此外,Span 80体积分数为2.0%～3.0%时,制备的微胶囊囊壁光滑、均一,平均粒径约为60μm。制备的微胶囊在电场强度为2.5×106V/m时,具有良好的电场响应行为及可逆移动性。     

Enhancing Phosphate Grade Using Oleic Acid–Sodium Dodecyl Sulfate Mixtures

Upgrading of calcareous phosphate ores by reverse flotation in acidic media depends mainly on the chemical reagents used, especially the collectors. Anionic collectors are commonly used in phosphate flotation circuits; however, in the most cases each collector was tested separately. Although using the mixture of the anionic collectors in salt-type minerals flotation is very limited, it has several advantages over using each collector alone. Therefore, in the present paper, the mixture of oleic acid and sodium dodecyl sulfate (SDS) was tested and compared to the usage of each collector individually. A number of experiments were conducted to find out the optimal reverse flotation conditions for each collector in terms of collector dose, pH, and oleic acid to SDS (Ol:SDS) mixing ratio as main variables using factorial design. The design results showed that the Ol:SDS mixture, particularly at 1:1 mixing ratio, improves the phosphate grade with slight decrease in recovery in comparison with using each collector separately. The highest concentrate grade (>33% P₂O₅), with a recovery of 85%, was obtained at pH 6, 1:1 Ol:SDS mixing ratio, and collector dose 3.5 kg/t. In addition, using 1:1 mixing ratio drastically lowers the collector dose from 3.5 to 2 kg/t or even lower depending on the pH to achieve the concentrate grade required by phosphate industry (30% P₂O₅).     

Investigation on the effects of fluid intensification based preconditioning process on the decarburization enhancement of fly ash

Fly ash (FA) is a complex and abundant solid waste created by humans, and has caused environmental issues, for which flotation is an effective technique employed before its comprehensive utilization. However, the complex and hydrophilic characteristics of FA particles cannot naturally fulfill the selective separation by common flotation. Therefore, this study aims to provide an insight into fluid intensification effects on flotation to achieve the enhancement of FA surface property and decarburization. The relevant effects and mechanisms are investigated, based on the measurements of zeta potential, infrared spectroscopy, contact/wrap angle, induction time, size distribution and scanning electron microscopy–energy dispersive spectrometry. Experimental results manifested that the maximum unburned carbon recovery (73.25%) and flotation rate (0.2037 s^-1) were achieved with preconditioning energy inputs of 14.23 and 6.57 W·kg^-1 respectively. With increasing preconditioning energy inputs, fluid intensification effects could promote the inter-particle collision/attrition, detachment of hydrophilic existence and collector adsorption on particles. Correspondingly, absorbance of some hydrophobic and hydrophilic functional groups was strengthened and weakened respectively, which accounted for the improved interfacial properties, reflected as the increased contact and wrap angles, together with declined induction time. Overall, this article revealed the positive influences of fluid intensification based preconditioning process on rendering particle surface hydrophobic and improving separation performance.     

Diesel Oil Removal by Froth Flotation Under Low Interfacial Tension Conditions II: Continuous Mode of Operation

Abstract

The objective of this study was to investigate the relationship between interfacial tension (IFT) and foam characteristics and the efficiency of diesel oil removal from water in a continuous froth flotation column. The effects of operational parameters, including surfactant concentration, salinity, oil-to-water ratio, foam height, air flow rate, and hydraulic retention time (HRT) on the oil removal were investigated in the continuous mode of a froth flotation operation and compared to batch operation results. Unlike the batch system, for the continuous system used in the present study, having only branched alcohol propoxylate sulfate sodium salt surfactant (C_14–15(PO)₅SO₄Na) and NaCl present in the solution yielded such poor foam characteristics that a stable froth which overflowed the flotation column could not be produced, so the addition of sodium dodecyl sulfate (SDS) as a froth promoter was used to improve the foam stability. Unlike the batch froth flotation system with only C_14–15(PO)₅SO₄Na, the continuous froth flotation with the mixture of C_14–15(PO)₅SO₄Na and SDS, it was not possible to find a SDS and a NaCl concentration at which both ultralow IFT and good foaming were both achieved. Foam formation, stability, and production rate were found to be crucial parameters to the froth flotation efficiency. The continuous froth flotation system offers a high diesel oil removal of 96% in the single stage unit. Demonstration of efficient operation in the continuous mode in this work is important to the practical application of froth flotation in large scale processing.     

温度对等摩尔CTAB-SDS复配体系表面张力及乳化性能的影响

测定了十六烷基三甲基溴化铵(CTAB),十二烷基硫酸钠(SDS)及它们等摩尔复配体系在不同温度下的表面张力及乳化性能。复配体系的γCMC从10℃的63.67 mN/m下降到90℃的36.38 mN/m,比相应单一体系的γCMC还略低,表现出高温下较高的表面活性。相应的单一体系的CMC值变化不明显,而CTAB-SDS体系的CMC却减少近一半。这些表面活性剂形成的乳液稳定性随温度升高而下降,与表面活性无关。90℃时复配体系的乳液分出10 mL水层的时间只需0.37 m in,使中和电荷加高温有可能成为一种较好的破乳方法,高温时等摩尔CTAB-SDS的高表面活性与所形成乳液的不稳定性使其有可能较好地应用于催化一些两相反应。     

沉淀pH值对TiO_2-SiO_2负载催化剂催化还原NO性能的影响

采用共沉淀法,在不同pH值下制备了3种TiO2-SiO2(TS)复合氧化物,采用BET、XRD、NH3-TPD和FTIR等方法对样品进行了表征;并以3种TS为载体,负载CuO、Cr2O3和CeO2活性组分,考察了不同Cu-Cr-Ce/TS催化剂在140～220℃NH3选择性催化还原NO的性能。结果表明,以pH值10～11的TS载体制备的Cu-Cr-Ce/TS催化剂具有最优的低温活性,这是由于该载体具有较大的比表面积和更多弱酸中心,能吸附大量易于与NO反应的氨。     

明胶对十二烷基硫酸钠／十六烷基溴化吡啶复配体系泡沫的稳定作用

通过对表面张力和溶液黏度的测试探讨了明胶对十二烷基硫酸钠（SDS）／十六烷基溴化吡啶（CPDB）复配体系泡沫的稳定作用。结果表明，明胶与表面活性剂复配体系形成的泡沫流体，起泡能力强，稳定性好，其主要原因是明胶与SDS／CPDB缔合成聚集体，聚集体的疏水作用阻止了液膜间的液体流失。     

BUBBLE AND FOAM SEPARATION OF EMULSIFIED BITUMEN FROM TAR SAND WASTEWATER

Process waters generated by the steam purging of tar sand deposits in Vernal, Utah, were treated by means of second-stage foam separation and air flotation operations. Among the independent process variables considered were hydraulic detention time, air flowrate. temperature, and polymer or surfactant addition level. System performance evaluations were based on second-stage effluent levels of total organic carbon (TOC), chemical oxygen demand (COD), suspended solids (SS). total solids (TS), and turbidity. The results indicated that the most effective second-stage system studied was air flotation aided by polymer addition. Removals of TOC, COD, and SS accomplished by this system exceeded 98 percent.