共查询到18条相似文献,搜索用时 46 毫秒
1.
2.
3.
全氟辛烷磺酸/全氟辛酸(PFOA/PFOS)由于存在有争议的环境污染和生物蓄积等问题,已经成为全世界关注的焦点之一,寻找能够替代PFOA/PFOS的新型含氟表面活性剂具有重要的意义.本文综述了可能替代PFOA/PFOS新型含氟表面活性剂的合成路线和方法,并按照分子结构进行了分类,着重介绍了以下4类:①端基为CF3O或(CF3)2N系列表面活性剂;②短氟链系列表面活性剂;③基于VDF或TFP系列表面活性剂;④全氟聚醚系列表面活性剂;同时对4类新型替代物的表面活性、生物降解性及在乳液聚合中的应用进行了归纳总结.目前PFOA/PFOS替代物的研究趋势,主要朝着降低含氟表面活性剂中氟元素比例、含减少氟链“有效长度”及插入N、O等杂原子等方向发展,使得新型含氟表活性剂更易降解、更环保、更安全. 相似文献
4.
5.
7.
8.
从外墙涂料耐沾污性影响因素的角度出发,揭示含氟表面活性剂对户外耐沾污性能影响的基本作用原理,并通过人工耐沾污测试以及1 a的户外曝晒实验加以验证.结果 表明,含氟表面活性剂对提升外墙涂料的耐沾污性能有一定的帮助.最后,探讨了含氟表面活性剂的全氟烷基分子链结构对环境可持续发展的重要影响,以此指明其未来的发展方向. 相似文献
9.
10.
11.
12.
含氟表面活性剂作为特种表面活性剂的一种,正凭借其高表面活性、优良的耐热性、稳定性以及憎水、憎油的特性,在工业生产中起到不可替代的作用.选择比较了几种常用的表面活性剂合成方法,并合成了全氟丁基磺酰氟季铵盐. 相似文献
13.
14.
M. Z. Mohamed 《Journal of surfactants and detergents》2008,11(2):175-179
Four fluorinated cationic surfactants were prepared by condensing 2,2,3,3, tetrafluoro-1-propyl chloroacetate with stoichiometric
amounts of pyridine, 2-hydroxypyridine, 8-hydroxyquinoline and 8-hydroxyquinaldine to produce four quaternary ammonium salts.
The surface and biocidal properties of these surfactants were investigated. Surface properties of their solutions including
surface tension, critical micelle concentration (CMC), effectiveness (Πcmc), maximum surface excess (Γmax) and minimum surface area (A
min) were investigated with respect to different concentrations at 25 °C. Standard free energies of micellization and adsorption
of the prepared surfactants in the aqueous solution were studied. The biocidal activity was determined via the inhibition
zone diameter of prepared compounds which tested against six strains as a representative group of microorganisms.
相似文献
M. Z. MohamedEmail: |
15.
16.
Three fluorinated cationic surfactants were prepared by condensing N-methyl diethanol amine pentafluoro benzoate with stoichiometric amounts of octyl, dodecyl or hexadecyl bromide. The surface
properties and parameters were investigated to find the relationship between the structures of the hydrophobic portion of
such compounds. The properties studied include surface tension, critical micelle concentration (CMC), effectiveness (Πcmc), maximum surface excess (Γmax) and minimum surface area (Amin) were investigated with respect to different concentrations at 25 °C. Standard free energies of micellization and adsorption
of the prepared surfactants in the aqueous solution were studied. The values of Γmax, standard free energies of micellization
\Updelta \textG\textmic\texto \Updelta {\text{G}}_{\text{mic}}^{\text{o}} and adsorption
\Updelta \textG\textads\texto \Updelta {\text{G}}_{\text{ads}}^{\text{o}} were found to increase with the chain length, while the cmc and minimum surface area occupied by one molecule Amin were found to decrease. The biocidal activity was determined through the inhibition zone diameter of prepared compounds which
were measured against five strains of a representative group of microorganisms. 相似文献
17.
以三氟乙酸乙酯和N,N-二甲基乙二胺为原料,经酰化反应制得中间体NDAET;然后将NDAET与溴代十二烷发生季铵化反应得到氟化季铵盐表面活性剂N,N-二甲基-N-{2-[(2,2,2-三氟乙酰基)氨基]乙基}-1-十二烷基铵溴化物(NDAET-12)。通过FTIR、13CNMR、1HNMR对其结构进行了表征。考察了反应物物质的量比、反应时间、反应温度、溶剂用量对NDAET-12产率的影响。在单因素实验的基础上,采用正交实验对NDAET-12的合成工艺进行了优化。NDAET-12的最佳合成工艺条件为:n(NDAET)∶n(溴代十二烷)=1.0∶1.3,NDAET质量为2.76g,反应时间12h,反应温度90℃,溶剂用量为20mL。在该条件下进行平行验证实验,得到NDAET-12的平均产率为86.75%。热重分析表明,NDAET-12是一种热稳定性较好的表面活性剂。对NDAET-12的临界胶束浓度(CMC)、表面活性和乳化性能进行了测定。NDAET-12的CMC为0.8 g/L,γCMC=25.15 mN/m,表面活性较好。与十二烷基三甲基溴化铵(DTAB)和十六烷基三甲基溴化铵(CTMAB)相比,NDAET-12从乳化体系中分出10mL所需要的时间最长,为473s,具有优异的乳化性能。 相似文献
18.
Synthesis and Surface Activities of Novel Succinic Acid Double-Tailed Sulfonate Fluorinated Surfactants 下载免费PDF全文
Luqing Zhang Bing Geng Quanxuan Lu Anhou Xu Shuxiang Zhang 《Journal of surfactants and detergents》2016,19(3):559-565
In this study, four environmentally friendly succinic acid double-tailed sulfonate fluorinated surfactants were synthesized from maleic anhydride, fluoroalkyl alcohols, namely 1-(1H,1H,7H-Dodecafluoroheptyloxy) ethanol, 1-(1H,1H,5H -octafluoropentyloxy) ethanol, 1-(1H,1H,3H-tetrafluoropropoxy) ethanol, and 1-(1H,1H -trifluoroethyoxy) ethanol, and sodium hydrogensulfite. The surfactant structure was characterized by FT-IR, 1H NMR, and 19F NMR . Thermogravimetric results showed that the fluorinated surfactants were stable up to relatively high temperature. The Krafft points of the four novel succinic acid double-tailed sulfonate fluorinated surfactants were all below 0 °C. The lowest CMC value for the synthesized four double-tailed fluorine surfactants is about 0.076 mmol L?1, far less than that of ammonium perfluorooctanoate (PFOA), demonstrating that double-tailed surfactants have higher surface activity than surfactants with one fluoroalkyl chain. The replacement of alkyl groups with oxyethylene groups enhances the hydrophilicity of the obtained fluorinated surfactants. Based on these findings, the synthesized surfactants may be environmentally friendly alternatives to PFOA and exhibit promising potential in industry applications. 相似文献