Volume 49, Issue 5

Fabric softeners are mainly used to reduce roughness and static electricity of textiles, as well as adding a scent to them. In this paper we study how fabric softeners are related to odour properties on clothing. We combine a Norwegian consumer survey with a sensory test on odour development on four different materials used in sports clothing. Samples went through several cycles of use with sweating, washing, and airing and the odour was evaluated at 11 stages. Washing was performed either with or without a fragrance-free domestic rinse cycle softener. Sensory test showed that use of softener increased odour on polyester garments. Survey results showed that a larger number of respondents who used softeners experienced problematic odours in laundry compared to those who did not use softeners.

On pseudo-first order conditions, the monomeric species of Cr(VI) was found to be kinetically active in the absence of phenanthroline (phen) whereas in the phen-promoted path, the Cr(VI)-phen complex undergoes a nucleophilic attack by glycerol to form a ternary complex which subsequently experience a redox decomposition leading to glyceraldehydes and Cr(III)-phen complex. The effect of the cationic surfactant, cetyl pyridinium chloride (CPC); anionic surfactant, sodium dodecyl sulphate (SDS) and nonionic surfactant, triton X-100 (TX-100) on the unpromoted and phen-promoted path have been studied. Micellar effects have been explained by considering the preferential partitioning of reactants between the micellar and aqueous phase.

Adsorption of Cl 2 out of aqueous media by TDRP (tire derived rubber particles) was investigated. For this propose batch system and sodium hypochlorite solutions were used on controllable conditions. The kinetic data were followed more closely to the pseudo-first-order model, the adsorption rate and the effecting parameters such as substrate initial concentration, the TDRP relative quantity, temperature, pH and ionic strength; were studied. The saturation equilibrium and the related parameters (initial concentration, temperature and pH) were also studied. The adsorption isotherm was established and compared to the activated carbon adsorption isotherm. Linearized Langmuir and Freundlich models were tried to estimate the adsorption constants. It was estimated through this study that the adsorption rate is positively affected by rising temperature, adsorbent concentration, TDRP relative quantity, and acidity. The adsorption equilibrium was shifted towards higher adsorption capacity by substrate concentration, temperature and acidity. The adsorption data could be applied to Freundlich and Langmuir and fitted more with Freundlich model. Activation enthalpy of adsorption, the adsorption thermodynamic parameters, the Freundlich and Langmuir constants were obtained.

In this study granular activated carbon (GAC) was used as pretreatment for foul control in ultrafiltration (UF) membrane process. First the adsorptive parameters for phenol, chlorophenol, nitrophenol and hydroquinone on GAC were determined. The equilibrium data fits well to Langmuir adsorption isotherm rather than Freundlich model. Breakthrough curves were obtained from fixed bed experiments and column parameter were calculated from it. GAC filters were then used in combination with UF membrane system. The percent retentions of the four organic substances under study were determined and the declines in flux were observed. The problems associated with powdered activated carbon like cake formation over membrane surface, long back wash time and blackening of pipes were not observed for GAC.

Electrical conductivity was measured for aqueous solutions of long-chain guanidine surfactants (G12 and MG12) at different temperatures and with various added counter ions. The critical micelle concentration (cmc) of these surfactants determined from the specific conductivity (κ) vs. concentration (c) plot is lower than those of the typical cationic surfactants, such as alkyltrimethylammonium chloride with the same hydrocarbon chain length. The electrical conductivity data were analyzed according to the mixed electrolyte model of micelle solution, and the degree of counter ion binding (β) was calculated. The thermodynamic parameters for micelle formation were estimated using the values of cmc and β as a function of temperature. The more negative ΔG mic for MG12 indicates more favored micellization. The contribution of entropy term to the micelle formation is superior to that of enthalpy term in the system under study, which indicates micellization is entropy driven. By comparing the cmc and ΔG mic it is evident that all cmc decreases and the more observed negative ΔG mic in the presence of different added salts. The anion effect on the guanidine surfactants micelle formation with added salts showed the micelle forming efficiency order as: Cl − < Br − < NO 3 − < Ac − .

This paper presents the reasons for the differences in interface tension and emulsion stability of Span60, Tween20, Tween60, Tween80 from the perspective of the molecular structure. For a surfactant emulsion, there is no complete correlation between interfacial tension and emulsion stability. Interface tension cannot determine the emulsion stability, but the molecular structure of the surfactant is the determinant of both the interface tension and emulsion stability. The branching degree of hydrophilic group, carbon chain length of hydrophobic group and carbon-carbon double bond had played a very important role. The clarification of the effect of molecular structure has significant theoretical meanings for modifying and synthetizing new surfactants.

Surfactants are widely used in the leather-making processes. The structure and property of surfactant obviously affect the quality and performance of leather. In this paper, a novel anionic surfactant, organosilicone modified sodium sulfonate of alkanolamide succinic acid monoester with palm oil was synthesized. Firstly palm oil was amidated with diethanolamine, then grafted with hydroxy-terminated silicone oil, esterified with maleic anhydride and sulphited with sodium bisulfite in sequence. The emulsification properties and fatliquoring performance of the prepared surfactant were tested. The influence of the mass percentage of reactants, the reaction temperature and time on the surface tension, the emulsifying activity and stability of the prepared surfactant were investigated. The FT-IR spectra analysis showed that under optimised conditions the novel surfactant was obtained. The fatliquoring application experiments showed that the novel surfactant is an excellent leather fatliquor.

Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). 8-Hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PY) reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with maleic anhydride (MA) to synthesize the PA tagged, phosphate and nitrogen free CaCO 3 inhibitor MA-APEL-PA. Structures of PA, APEG, APEL, and MA-APEL-PA were obtained by FT-IR and 1 H-NMR measurements. The observation shows that the dosage of MA-APEL-PA plays an important role on CaCO 3 inhibition. The effect on the formation of CaCO 3 was investigated by a combination of scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) analysis. The relationship between MA-APEL-PA's fluorescent intensity and its dosage was also studied. Correlation coefficient '9 of MA-APEL-PA's fluorescent intensity and its dosage is 0.9997. MA-APEL-PA can be used to measure accurately the polymer consumption on line besides providing excellent CaCO 3 inhibition.

Novel Gemini surfactants containing amide group linkage were prepared with fatty acid, diamine and dihalide by simple organic reaction, and characterized with IR, and elemental analysis (EA). As the results show, the structures of the products obtained correspond to the target compounds designed. By surface tension scanning, these Gemini surfactants have excellent surface activity with low c.m.c. and surface tension, the lowest c.m.c value was 9.12 × 10 −6 mol/L for surfactant Bi-18(4).

Alkyl polyglucosides are non-ionic surfactants consisting of a hydrophilic saccharide moiety and a hydrophobic fatty alkyl chain. They are synthesized from renewable raw materials and have excellent ecotoxicological profiles and are readily biodegradable. The alkyl polyglucosides are mixtures of homologues, anomers and isomers. The alkyl polyglucosides with a longer alkyl chain biodegrade faster than those with a shorter one. The short to medium alkyl chain containing alkyl polyglucosides are water soluble. They exhibit favorable wetting and surface tension reduction, electrolyte and hard water tolerance, great stability in wide pH range, synergism with other surfactants and act as hydrotropes and dispersants. The dermatological, toxicological, mildness and high compatibility to skin make alkyl polyglucosides superior to all other existing surfactants. They show good functionality in various applications like detergents, food emulsifiers, cosmetic surfactants, industrial emulsifiers and pharmaceutical granulating agents.