نتایج جستجو برای: surfactants

تعداد نتایج: 9553  

2014
Salwa M.I. Morsy

Surfactants are characterized by the essential features that we saw in sodium oleate. A surfactant molecule has a hydrophilic (water-loving) head and a long hydrophobic (water-hating or oil-loving) tail. For this reason, we often describe surfactants is being amphiphilic molecules they love everything. Surfactants can be categorized according to the charge present in the hydrophilic portion of ...

Journal: :Physical chemistry chemical physics : PCCP 2015
Hwankyu Lee Tae-Joon Jeon

Imidazolium-based ionic surfactants with hydrocarbon tails of different sizes were simulated with lipid bilayers at different salt concentrations. Starting with the random position of ionic surfactants outside the bilayer, surfactants with long tails mostly insert into the bilayer, while those with short tails show the insertion of fewer surfactant molecules, indicating the effect of the tail l...

Journal: :Environmental Health Perspectives 1995
Tibor Cserháti

Nonionic surfactants are amphipathic molecules consisting of a hydrophobic (alkylated phenol derivatives, fatty acids, longchain linear alcohols, etc.) and a hydrophilic part (generally ethylene oxide chains of various length). Although not as important commercially, tertiary amine and various sugar surfactants are also nonionic surfactants. Due to their favorable physicochemical properties, no...

2010
Jiwei Hu Xiaoyi Zhang Zhengwu Wang

This paper presents a review on recent progress in quantitative structure-property relationship (QSPR) studies of surfactants and applications of various molecular descriptors. QSPR studies on critical micelle concentration (cmc) and surface tension (gamma) of surfactants are introduced. Studies on charge distribution in ionic surfactants by quantum chemical calculations and its effects on the ...

1997
Debashish Chowdhury Prabal K. Maiti

The “head” part of surfactant molecules consist of a polar or ionic group. The “tail” of many surfactants consist of a single hydrocarbon chain whereas that of some other surfactants, e.g., phospholipids, are made of two hydrocarbon chains both of which are connected to the same head. In contrast, gemini surfactants2–5, consist of two single-chain surfactants whose heads are connected by a “spa...

2003
J. Chern L. Huang

Behavior of surfactant mixtures at solid-liquid interfaces was investigated using anionic-nonionic and catjonic-nonionic surfactants of different structures. The results show that adsorption of nonionic surfactants on alumina was enhanced significantly by the coadsorption of ionic surfactants. The adsorption beha vior of these binary surfactant mixtures was dependent upon the ratio of the two s...

2014
C. L. Yuan Z. Z. Xu M. X. Fan H. Y. Liu Y. H. Xie T. Zhu

Surfactants have wide use all over world. This study summarizes the characteristics and classification of surfactants. Surfactants have wide application in commodity and industry. A large number of surfactant containing wastewater are discharged into the environment, resulting in harming aquatic life, polluting the water and endangering human health. Therefore, it is important to monitor and co...

2014
Jeremy Cho

This thesis consists of an experimental investigation of the effect of surfactants on the boiling curve of water. Via adsorbtion to the boiling surface, surfactants alter the surface energy interaction during bubble formation at nucleation sites. The surfactants initially enhance the heat transfer coefficient at the onset of nucleate boiling due to higher nucleation density and higher bubble de...

2013
Naveen Kumar

Surfactants are an essential ingredient for cosmetic, toiletries and personal care products for enhancing their performance. Dimeric surfactants demonstrate superiority compared to conventional surfactants in all areas of application. Dimeric surfactants are extremely promising for utilization in various cosmetic formulations viz. shampoo, lotions, creams, conditioners etc. These surfactants po...

Journal: :Environment international 2006
Guang-Guo Ying

Surfactants are widely used in household and industrial products. After use, surfactants as well as their products are mainly discharged into sewage treatment plants and then dispersed into the environment through effluent discharge into surface waters and sludge disposal on lands. Surfactants have different behavior and fate in the environment. Nonionic and cationic surfactants had much higher...

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