Surfactants historical review

We review here results of computer simulations of monolayers, with an emphasis on those models that include significant molecular detail to the surfactant molecule. We start with a focus on hydrocarbon chains and simple head groups (typically a COOH group in either the neutral or the ionized state) and a historical focus. A less comprehensive review follows on simulations of surfactants of other types, either nonhydrocarbon chains or different head groups. More detailed descriptions of the general simulation techniques discussed here are available in a book dedicated to simulation techniques, for example, Allen and Tildesley [338] or Frenkel and Smit [339],... 

In the past five years, it has been demonstrated that the QELS method is a versatile technique which can provide much information on interfacial molecular dynamics [3 9]. In this review, we intend to show interfacial behavior of molecules elucidated by the QELS method. In Section II, we present the principle and the experimental apparatus of the QELS along with the historical background. The dynamic collective behavior of molecules at liquid-liquid interfaces was first obtained by improving the time resolution of the QELS method. In Section III, we show the molecular collective behavior of surfactant molecules derived from the analysis of the time courses of capillary wave frequencies. Since the... 

Cheng and English edited ACS symposium series which covers the solution and solid state NMR investigations for dendrimers, cellulose, polyurethane, polyolefins biopolymers, copolymers and so on. Spiess described a historical overview of role of NMR spectroscopy in polymer science. Newmark summarizes the two dimensional and pulsed gradient diffusion NMR experiments and their applications to polymers Shit et al. reviewed the analysis of polymer molecular weight and copolymer composition by NMR. Sasanuma summarized the the analysis of polyethers and polysulfides by NMR and theoretical calcula-tions Ardelean et al described the principle and its applications of diffusion studies by NMR. Roy et al summarized the structural analysis of Novolak resins by multidimensional NMR. Reviews about NMR study of surfactant polymer blends and the structural elucidation of supramocules are published. 

More commonly, demulsifiers are surface-active substances (surfactants) that have the ability to destabilize emulsions. This involves reducing the interfacial tension at the emulsion interface, often by neutralizing the effect of other surfactants that are stabilizing the emulsion. An example is antagonistic action - addition of an O/W promoter to break a W/O emulsion (see sensitization in Section 5.4). Mikula and Munoz [81] trace the historical evolution of demulsifier chemistry and the effective concentration range. Several reviews of demulsifier chemistry and properties are also available [73,75 - 79,82 - 87]. In order to perform, a demulsifier should have the following parameters ... 

The text is kept as pedagogical and as simple as possible, and the literature review is not exhaustive, particularly on theoretical aspects, but rather selective of important fundamental developments, historical milestones, and technological breakthroughs. The scope is limited by editorial choice to systems containing ionic surfactants and some ionic-nonionic mixtures such as those involving pH-sensitive systems. 

Demulsifiers are frequently surfactants the relationship between demulsifier stmcture and performance has been studied for over 50 years [94]. Mikula and Munoz [88] trace the historical evolution of demulsifier chemistry and effective concentration range, and several reviews of demulsifier chemistry and properties are also available [95-99]. A demulsifier must displace or counteract the emulsifying agent stabilizing the emulsion, and promote aggregation and coalescence of the dispersed phase into large droplets that can be separated [92,93]. 

This article aims to review the recent developments in the area of BCP-surfactant mixed systems in aqueous solution and is organized as follows For historic reasons and due to the high number of publications devoted to Pluronics, triblock copolymers will be discussed first, and their behavior in aqueous mixtures with different surfactants will be reviewed (Section 2). 

Mixtures of oil and water that are cosolubilized by a surfactant and alcohol mixture have been used since the turn of the century to make detergents for wool in Australia, or self-shining floor wax, or other applications as reported in the first available review on the topic [1]. For quite a while, they were more a curiosity or the result of a whimsical formulation trick to attain a so-called soluble oil, for instance, than a really high-tech product. The tale of the early research carried out on soap and other cleaning products has been told recently in a wonderful chapter that R. Laughlin dedicated to these historical moments of surfactant science in his remarkable recent book [2]. 

Waters has written a well-balanced review article on environmental analysis of cat-ionics giving a historical perspective on the development and application of the various procedures, including official methods (153). Published methods for determination of cationic surfactants in the environment are summarized in Tables 7 and 8. 

---