含氟表面活性剂发展现状及应用领域简要介绍

含氟表面活性剂（简称：FS）是近些年来逐步商品化的一种特殊性能的表面活性剂。与普通表面活性剂不同之处，FS主要以全氟烷基或全氟烯基或部份氟化了的烷基等作为表面活性剂中的疏水基部份，然后再按需要引入适当的连接基及亲水基团，根据亲水基团性质的不同分别制得阴离子型、阳离子型、非离子型及二性型等不同系例的FS产品。[第一段]     

含氟表面活性剂发展简况

含氟表面活性剂（简称：FS）是近些年来逐步商品化的一种特殊性能的表面活性剂。与普通表面活性剂不同之处，FS主要以全氟烷基或全氟烯基或部份氟化了的烷基等作为表面活性剂中的疏水基部份，然后再按需要引入适当的连接基及亲水基团，根据亲水基团性质的不同分别制得阴离子型、阳离子型、非离子型及二性型等不同系列的FS产品。     

结构片断法计算离子型表面活性剂的HLB值

运用结构片断法计算离子型表面活性剂的疏水值logP,并将疏水值概念引入Davies基团贡献法以代替该模型中亲油基的基团数,从而建立了计算离子型表面活性剂HLB值的新模型为:HLB=7+∑亲水基基团数-∑疏水基logP。通过与文献列举的17个不同系列离子型表面活性剂的HLB值对照表明,该新模型的计算值与文献值的平均相对偏差为1.68%。采用非线性方法拟合了烷基硫酸钠,烷基磺酸钠和烷基三甲基溴化铵3类典型离子型表面活性剂的CMC和HLB的关系,并得到了其关联方程,拟合结果表明,由新模型得到的关联方程其复相关系数R2>0.988。     

表面活性剂--聚氧乙烯基甲基聚硅氧烷

该剂系由日本公司开发的聚硅氧烷类表面活性剂。该表面活性剂系由一个疏水基团和一个亲水基团所组成。疏水摹聚硅氧烷油为甲基聚硅氧烷，亲水基则采用非离子型表面活性剂中的聚氧乙烯基。     

表面活性剂在农药加工中的作用

表面活性剂是指那些具有很强表面活性、能使液体的表面张力显著下降的物质。此外表面活性剂还应具有增溶、乳化、润湿、消泡和起泡等应用性质。表面活性剂的分子结构特点是具有不对称性。整个分子可分为两个部分,一部分是亲油的非极性基团,叫作疏水基或亲油基;另一部分是极性基团或亲水基。两部分分处两端,形成不对称结构。     

松香改性非离子表面活性剂研究进展

松香是一种丰富廉价的可再生性天然资源。松香分子结构中的三环菲骨架和高级脂肪酸的长链烃基一样具有疏水基，并可通过其中的羧基、双键等活性基团引入亲水基，故松香可代替石油化工产品作为非离子表面活性剂的合成原料，符合当前绿色化学和可持续发展要求。综述了国内外松香基非离子表面活性剂的研究进展，讨论了该类非离子表面活性剂使用过程中的主要优势以及存在的问题，对该研究领域的发展前景进行了展望。     

磺酸盐型水性聚氨酯的研究进展

概述了磺酸盐型水性聚氨酯的性能特点,论述了磺酸盐型WPU的类型及其制备技术。磺酸盐亲水基团的引入方式有多种,可以通过小分子扩链剂引入,也可通过含有磺酸基团的聚酯或聚醚引入,或同时采用多种方式引入;除了磺酸盐亲水基团外,还可在水性聚氨酯的分子结构中引入羧酸基团、非离子型亲水基团等,形成混合内乳化剂,可大大提高水性聚氨酯合成过程的稳定性,并降低总亲水性基团含量,从而提高WPU的耐水性及其他性能。     

两亲聚氨酯的合成及研究进展

综述了两亲聚氨酯的合成方法和最新研究进展,阐述了两亲聚氨酯合成中亲水基团的引入方法,介绍了两亲聚氨酯材料在实际中的应用,并指出了两亲聚氨酯领域今后的发展方向。两亲聚氨酯材料中同时含有亲水和疏水组分,结构和性能易于通过改变配方调节,具有优良的综合性能,可用作防水透湿材料、高分子表面活性剂和医用材料等,是一类应用前景十分广泛的两亲性新材料。     

磺酸盐型低聚表面活性剂的合成研究进展

磺酸盐型低聚表面活性剂具有良好的界面活性及耐温抗盐等性能而广受国内外学者关注。本文基于亲油亲水基团的3种引入方法：单体联接法、疏水链加入法及极性头基加入法,重点综述了近十年来磺酸盐型低聚表面活性剂的合成,简要介绍了产物的表/界面张力、临界胶束浓度等物化性质以及乳化降黏、杀菌和驱油等应用性能。指出应注重产品结构与性能关系研究,通过分子设计开发性价比优异的新型磺酸盐低聚表面活性剂,优化合成工艺,加强与其它类型表面活性剂、聚合物组成的驱油体系研究,以实现其在三次采油中的工业应用。     

新型氟碳离子型表面活性剂的合成与性能

本文以全氟己基乙基溴、2-甲氨基乙醇等为原料,反应合成中间体N-甲基-N-全氟己基乙基乙醇胺,再分别与碘甲烷、氯乙酸钠反应,合成了两种新型氟碳离子型表面活性剂。通过红外光谱、核磁共振、表面张力、热重分析等方法对合成产物的结构和性能进行表征。结果表明,所合成的表面活性剂具有良好的表面性能及热稳定性。     

The relationship of structure to properties in surfactants

Changes in the various structural units present in surfactants strongly affect the interfacial properties shown by these materials. Such properties as surface tension reduction, micelle formation, wetting, foaming and defoaming, detergency, and dispersion of solids all show marked changes with variations in both the hydrophilic and hydrophobic portions of the surfactant molecule, reflecting the processes occurring on a molecular level. Changes in these properties caused by such factors as the length and nature of the hydrophobic group, branching or unsaturation in the hydrophobic group, the nature of the hydrophilic group and its position in the molecule, and the presence or absence of an ionic charge are described and explained in terms of the molecular processes involved. Presented at the AOCS Short Course, “Update on Detergents and Raw Materials,” Lake Placid, New York, June 1971.     

Properties and applications of amphoteric surfactant: A concise review

Amphoteric surfactants have long hydrophobic hydrocarbon chain and hydrophilic positive as well as negative charged center connected with each other by a spacer group. Thus, this type of surfactant maintains overall charged neutrality. The properties of amphoteric surfactants depend primarily on the length of the hydrophobic hydrocarbon chain, the number of methylene segments in the spacer, the positive and negative charged groups, and their relative position. The ionic activity of amphoteric surfactants is influenced according to the pH value of the solvent. They display cationic behavior below the isoelectric points and anionic behavior at a higher pH. They take the shape of zwitterions in the area of the isoelectric point. In fact, amphoteric surfactants can be parted into pH-sensitive and pH-insensitive surfactants. The pH-insensitive surfactants stay as zwitterionic form irrespective of the pH of the solution. This surfactant has some unique features because of its precise molecular structure as follows: high water solubility, high surface activities, a wide isoelectric range, low critical micelle concentration (CMC), high foam stability, low toxicity, low irritating, excellent biodegradability, bioactivity, interface change, and so on. Because of these special characteristics, amphoteric surfactants have been immensely interested in many applications in the scientific community, including cosmetics, chromatography, enhanced oil recovery, electrochemistry, nanoscience, polymer chemistry, and waste water treatment. This review aims to study about amphoteric surfactants, which have only one hydrophobic hydrocarbon tail and two oppositely charged hydrophilic headgroups connected with each other by a spacer group and its properties, applications in various academics and industrial fields.     

纤维素基水凝胶的研究进展

纤维素是世界上最丰富的天然、可再生以及可生物降解的高分子材料，在化工、材料等领域有广泛的应用。本文主要对近几年来纤维素基水凝胶的研究进展进行了归纳总结。首先，介绍了纤维素基水凝胶的研究背景。其次，列举了纤维素水基凝胶的交联方法，主要有物理交联与化学交联。其中物理交联有氢键交联、疏水性交联、离子交联等，化学交联则是酯化交联、迈克尔加成、自由基共聚合、动态共价键交联等。最后，重点介绍了纤维素基水凝胶在可降解性、生物医学性、亲水性、吸附性、导电性等领域方面的应用。此外，对于纤维素基水凝胶材料在高机械性和产业化制备等方面的发展进行了展望。     

A Review of Gemini Surfactants: Potential Application in Enhanced Oil Recovery

Gemini surfactants are a group of novel surfactants with more than one hydrophilic head group and hydrophobic tail group linked by a spacer at or near the head groups. Unique properties of gemini surfactants, such as low critical micelle concentration, good water solubility, unusual micelle structures and aggregation behavior, high efficiency in reducing oil/water interfacial tension, and interesting rheological properties have attracted the attention of academic researchers and field experts. Rheological characterization and determination of the interfacial tension are two of the most important screening techniques for the evaluation and selection of chemicals for enhanced oil recovery (EOR). This review deals with rheology, wettability alteration, adsorption and interfacial properties of gemini surfactants and various factors affecting their performance. The review highlights the current research activities on the application of gemini surfactants in EOR.     

Preparation and Characterization of C10–C14 Alkyl Cellulose Ester Sulfate Surfactant

The aim of this work is to synthesize surfactants based on cellulose with different molecular weights. Raw cotton cellulose was tailored into cellulose segments with different molecular weights by a hydrothermal process, then the average degree of polymerization (DP) was determined by viscosimetry and the molecular weight distribution was estimated by gel permeation chromatography. The C₁₀–C₁₄ alkyl cellulose ester sulfate surfactants were prepared by hydrophilic sulfonation and hydrophobic esterification. The surface tension of the surfactants solution was obtained by the Wilhelmy plate method. Results showed that the cellulose segments presented a broader distribution compared with the raw material. The critical micelle concentration (CMC) value decreased from 1.08 to 0.86 wt% as the hydrophobic chain length was increased from 10 to 14. The CMC values of cellulose surfactants with C₁₄-acyl chloride hydrophobization decreased from 1.32 to 0.86 wt% as the DP was decreased from 2,700 to 296.     

Synthesis and characterization of block-copolymer surfactants with specific interactions with associative thickeners

It has been theorized that, in order to get some positive interaction with the associative thickeners, the surfactants should have, at the end of the hydrophilic sequence, a short hydrophobic group. On the other hand, in order to control the hydrophilic lipophilic balance (HLB), it is wise to use well controlled polymerization procedures to build the block-copolymer. Then, the safer and simplest way to reach such goal is to use the ring-opening living anionic polymerization of butylene oxide (hydrophobic sequence) and then ethylene oxide (hydrophilic sequence); this living block-copolymer is then killed using an alkyl or aryl chloride (or bromide). However, because such surfactants include at the end of the hydrophilic sequence a hydrophobic group, they tend to adopt, when adsorbed onto hydrophobic latex particles, a back-folded conformation. In order to get for them an extended conformation, the hydrophilic sequence should have charges able to repel each other. This was achieved upon preparing block-copolymers of acrylic acid and butylacrylate, using a controlled radical polymerization with reversible addition fragmentation transfer (RAFT) agents, starting with the poly(acrylic acid) (PAA) sequence. Then, the radical fragment coming from the RAFT agent is at the end of the PAA sequence. A few rheological data actually confirm the interest of the concept.     

Synthesis and Surface Active Properties of Novel Carbohydrate-based Cationic Surfactants

The synthesis of new cationic carbohydrate surfactants is presented in this paper. The obtained surfactants have structures that are typical for saponins, which contain fatty amide hydrophobic chains and hydrophilic heads with cationic carbohydrate units. Their surface active properties and biodegradability have been studied. For two types, the biodegradability was above 85% and comparable to standard carbohydrate surfactants.     

Bacterial Cellulose: Production,Characterization, and Application as Antimicrobial Agent

Bacterial cellulose (BC) is recognized as a multifaceted, versatile biomaterial with abundant applications. Groups of microorganisms such as bacteria are accountable for BC synthesis through static or agitated fermentation processes in the presence of competent media. In comparison to static cultivation, agitated cultivation provides the maximum yield of the BC. A pure cellulose BC can positively interact with hydrophilic or hydrophobic biopolymers while being used in the biomedical domain. From the last two decades, the reinforcement of biopolymer-based biocomposites and its applicability with BC have increased in the research field. The harmony of hydrophobic biopolymers can be reduced due to the high moisture content of BC in comparison to hydrophilic biopolymers. Mechanical properties are the important parameters not only in producing green composite but also in dealing with tissue engineering, medical implants, and biofilm. The wide requisition of BC in medical as well as industrial fields has warranted the scaling up of the production of BC with added economy. This review provides a detailed overview of the production and properties of BC and several parameters affecting the production of BC and its biocomposites, elucidating their antimicrobial and antibiofilm efficacy with an insight to highlight their therapeutic potential.     

具有附加值的表面活性剂的现状及研究进展(续完)

4 通过物理触发来影响表面活性剂的自组装 高性能表面活性剂能够对多种化学触发因素产生反应.这些方法的缺点是刺激响应过程相对缓慢,而且整个体系的组成可能会改变.纯物理触发的优点是——完全可逆性的机率更高,因为体系的组成保持不变因而它们可以更快地应用.     

Cationic Surfactants as Disinfectants against SARS-CoV-2

The virucidal activity of a series of cationic surfactants differing in the length and number of hydrophobic tails (at the same hydrophilic head) and the structure of the hydrophilic head (at the same length of the hydrophobic n-alkyl tail) was compared. It was shown that an increase in the length and number of hydrophobic tails, as well as the presence of a benzene ring in the surfactant molecule, enhance the virucidal activity of the surfactant against SARS-CoV-2. This may be due to the more pronounced ability of such surfactants to penetrate and destroy the phospholipid membrane of the virus. Among the cationic surfactants studied, didodecyldimethylammonium bromide was shown to be the most efficient as a disinfectant, its 50% effective concentration (EC50) being equal to 0.016 mM. Two surfactants (didodecyldimethylammonium bromide and benzalkonium chloride) can deactivate SARS-CoV-2 in as little as 5 s.