Search

Studies on effect of capric acid and stearic acid based reactive phase change materials (rPCM) on physical properties and thermal comfort of cotton khadi fabric are reported by direct application of Capric acid (CA) and Stearic Acid (SA) as rPCM with Poly-Hydroxy-Amino-Methyl-Silicone reactive binder and MgCl2 as catalyst by simple pad-dry-cure technique (instead of cumbersome and costlier microencapsulation) which are embedded under PHAMS reactive binder film. Thermal characterization of pure Capric acid (CA), pure Stearic acid (SA) and mixture of each with PHAMS binder treated cotton substrate were carried out by cryogenic DSC at 0–100°C and at also at ambient (30°C) to 500°C. Between these two PCM materials, Capric Acid (CA) shows superior results. Amongst different concentrations of CA, 4% CA applied on Cotton khadi fabric with 2% PHAMS binder and 1/5th (on weight of PCM material) of MgCl2 catalyst shows good thermo-regulating character in cotton khadi fabric showing freezing temperature (Tf) 8.3°C, Melting Temperature (Tm) 22.6°C with melting enthalpy 34.1 J/g and freezing enthalpy 36.5 J/g. water vapor transmission value of 28.3 gm/hour/m2 and air permeability value of 262.3 ft3/ft2/min, showing favorable thermal comfort, enabling storage and release of heat energy to improve the thermal comfort with changing environmental conditions. [ABSTRACT FROM AUTHOR]

The aim of the present study is to standardize a protocol for optimization of pre-treatment, mordanting and dyeing of cotton khadi fabric with waste marigold flower petals. The effects of different single and combined double mordanting on dye-ability and colour fastness properties have been studied after optimization of aqueous extraction of marigold flower as natural dye. Mordants used are potash alum, aluminium sulphate, stannous chloride as metallic salt mordant and harda (myrabolan) from natural source as mordant assistant. After finalizing the mordants, dyeing process variables are standardized for dyeing cotton khadi fabric with waste marigold flower extract as selective natural dye applied on 3% H2O2 (30%) bleached cotton khadi fabric. Dyeing process variables studied are dyeing time, temperature, MLR, pH, mordant concentration, dye concentration and salt concentration for dyeing with prefixed mordant. Colour fastness to washing, rubbing, light and perspiration against use of different mordants and also against different dyeing process variables are also investigated. The results indicate that, this particular natural dye renders better appreciation of colour yield by pre mordanting with 15% aluminium sulphate and harda (50:50) as compared to other single mordants (potash alum and stannous chloride) and double mordants used. Use of double mordant in 15 % application level, shows maximum K/S value with overall good colour fastness than others. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Natural Fibers is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of peripheral substituents and axial ligands on the electronic structure and properties of iron phthalocyanine are investigated. The electronic configuration of iron phthalocyanine is determined mainly by the axial ligand-field strength but can also be affected by peripheral substituents.

The study was conducted on BN and AIN substitution using semiempirical (MNDO and PM3), density functional (B3LYP) theories. The substitution of AIN causes much more distortion of total electron density of C(sub 60) than BN, making the fullerence easier to oxidize and reduce and result indicates that AIN-fullerence was difficult to synthesize than their BN analogues.

With the help of several basis sets the ground-state geometries of the complexes of C2H2 and C2H4 with H+, Li+, and Na+ ions have been optimized at the B3LYP and MP2(full) levels of theory. The role of the covalent interaction in the Li+ and Na+ complexes is highlighted.

The cleavage of H-R bonds in the reaction MH + HR --- MH...HR --- M(eta2-H2)R, where M represents the 18-e transition metal hydrides, has been studied. The results of density functional theory B3PW91/LANL2DZ theoretical calculations showed that the 18-e transition metal hydrides split the H-R covalent bonds via H...H bonding, forming an eta2-H2 complex upon reaction with poor and moderate proton donors. The mechanisms for the reactions are elucidated.