Synthesis, Characterization and Surface Active Properties of Imidazolinium Surfactant Derived from Oleic Acid and Diethylenetriamine

This paper describes an efficient method for the synthesis of long chain alkylamido imidazolines by the reaction of diethylenetriamine and oleic acid under non-solvent microwave irradiation using calcium oxide as support and their comparison with conventional thermal condensation process. Synthesized imidazolines were then quaternized by using dimethylsulfate as a quaternizing agent and isopropanol as a solvent, to produce cationic imidazolinium salts which were evaluated for yield and cationic content. The instrumental techniques, viz. FT-IR and 1H-NMR verified the formation of imidazolines and its subsequent quaternization. The surface active and performance properties of cationic imidazolines in terms of c.m.c., surface tension, dispersability, emulsion stability, softening, rewettability and detergency were also reported.

Nonionic Surfactants: An Overview

Nonionic surfactants do not produce ions in aqueous solution. As a consequence, they are compatible with other types of surfactants and are excellent candidates to enter complex mixtures, as found in many commercial products. Nonionic surfactants are found today in a large variety of domestic and industrial products, such as powdered or liquid formulations. This review paper describes the history, properties, types and uses of nonionic surfactants.

Development of Cleavable Surfactants

Cleavable surfactants are of great interest for numerous reasons. These are amphiphiles in which a weak linkage has been deliberately inserted, normally, but not always, between the hydrophobic tail and the polar head group. Surfactant may degrade by chemical means, e.g., induced by acid, alkali, ultraviolet (UV) light, heat, or ozone. Acid- and alkali-labile surfactants have also attracted the attention in recent years. The main purpose for development of novel cleavable surfactants is to improve the biodegradation characteristics and the rate of biodegradation has consequently been studied for several of the surfactants. Alkali labile linkages that have been used for the purpose include normal ester bonds, betaine esters, and carbonates. This review deals the development of monomeric and gemini type cleavable surfactants.

Preparation and Performance Properties of a Series of Novel Anionic Gemini Surfactants

Anionic Gemini surfactants having two phosphate head groups and two decyl head groups were prepared in good yield. These surfactants were prepared by two step process. (i) Preparation of decyl phosphate from pyrophosphoric acid and decanol. (ii) Preparation of bis-phosphoric acid from decyl phosphate, (CH3)4NOH and different spacers by using acetonitrile as solvent. The synthesized surfactants structures were verified by FT IR, and 1H NMR spectroscopy. The physical and performance properties like surface tension and interfacial tension, foaming, wetting and emulsion stability of disodium salts of bis-phosphoric acids were also evaluated. The effects of the spacers on the properties were analyzed. It was found that properties were significantly influenced by slight variation of spacers.

Coliforms removal in full-scale activated sludge plants in India

This paper investigates the removal of coliforms in full-scale activated sludge plants (ASP) operating in northern regions of India. Log2.2 and log2.4 removal were observed for total coliforms (TC) and fecal coliforms (FC), respectively. However, the effluent still contained a significant number of TC and FC which was greater than the permissible limit for unrestricted irrigation as prescribed by WHO. The observations also suggest that extended aeration (EA) process operating under high mixed liquor suspended solids (MLSS) and sludge retention time (SRT) is more efficient in the removal of coliforms. Further attempts have been made to establish the relationship between two key wastewater parameters, i.e. biochemical oxygen demand (BOD) and suspended solids (SS) with respect to fecal and TC. The relationships were observed to be linear with a good coefficient of correlation. The interrelationship of BOD and SS with coliforms manifest that improvement of the microbiological quality of wastewater could be linked with the removal of SS. Therefore, SS can serve as a regulatory tool in lieu of an explicit coliforms standard.

Laundry detergents: an overview

Nowadays laundry detergents are becoming increasingly popular as they can be metered automatically into the washing machine, impart softness, antistaticness, resiliency to fabrics, mild to eyes and skins and shows good dispersibility in water. Because it is consumed when it is used, the sale of laundry detergent is a rather large business. There are many different kinds or brands of laundry detergent sold, many of them claiming some special qualities as selling points. A Laundry detergent composition is a formulated mixture of raw materials that can be classified into different types based on their properties and function in the final product. The different classes of raw materials are surfactants, builders, bleaching agents, enzymes, and minors which remove dirt, stain, and soil from surfaces or textiles gave them pleasant feel and odour. The physico-chemical properties of surfactants make them suitable for laundry purposes. Laundry detergent has traditionally been a powdered or granular solid, but the use of liquid laundry detergents has gradually increased over the years, and these days use of liquid detergent equals or even exceeds use of solid detergent. This review paper describes the history, composition, types, mechanism, consumption, environmental effects and consumption of laundry detergents.

Imidazoline and Its Derivatives : An Overview

Imidazoline derivatives, a class of novel cationic surfactants are presently gaining importance in global detergent market due to their wide range of applications. These are extensively used mainly as fabric softeners and antistatic agents. The present communication reviews the preparation, reaction scheme, reaction rates and properties of imidazoline derivatives. The analysis of imidazoline derivatives, its mode of action, their biodegradation and various applications have also been discussed.

Ester Quats: The Novel Class of Cationic Fabric Softeners

Esterquats, which are quaternary ammonium compounds having two long (C(16)-C(18)) fatty acid chains with 2 weak ester linkages, represent a new generation of fabric softening agents, having replaced the dialkyldimethylammonium salts (e.g. DTDMAC and DSDMAC). The inclusion of ester linkages into the aliphatic chains has significantly improved the kinetics of biodegradation of the cationic surfactants, lowering the environmental exposure levels. This new generation of fabric softening agents combines a good environmental profile with the structural features required for an effective fabric conditioner. The present paper reviews the synthesis, types, actives combines a good environmental profile with the structural features required for a properties and applications of esterquats.

Spatio-temporal variations in population growth in India since 1901

"On the basis of census data we analyse population growth since 1901 first for India as a whole, secondly on State level. The spatio-temporal patterns suggest a process of innovation and diffusion with regard to the spatial change of natural increase. The southern States cover more stages of the model of demographic transition than the northern States. Explanations about these spatial differentials come for example [from] sociocultural differences between north and south determining two demographic regions according to Satpura Range." (SUMMARY IN GER AND RUS)

Calculation of water volume in step wells for cyclopicide application and its eco-epidemiological implication: mathematical validation of some theoretical considerations

Chemical treatment of step wells to kill cyclopoid vectors of guinea worm by temephos (50 per cent E. C.) at the dose of 1 ppm is now an important activity of the guineaworm eradication programme in India. Calculation of correct volume of water in step wells, to determine the exact quantity of temephos to be applied, therefore, deserves adequate attention to prevent over and underdosing of stepwells by the chemical. The prescribed method of calculation of water volume includes two formulae; pi r2h and 1 x b x h (where h = mean depth for uneven bottoms and is a single depth measurement for almost even bottoms). Field observations revealed that in many stepwells there were marked variations in depth within the same well. These differences in depth ranged from small to very large in some wells. Since these depth variations would lead to miscalculation of water volume by existing method and the dose of temephos to be applied, with eco-epidemiological consequences, new formulae have therefore been deduced for conceivable patterns of depth variations by geometrical and algebric applications. The new formulae will permit calculation of, nearest to, exact quantity of temephos required for application. These formulae have been validated by an example.