Polyester textile functionalization through incorporation of pH/thermo-responsive microgels. Part II: polyester functionalization and characterization

A new approach to functionalize the surface of polyester textiles is described in this study. Functionalization was achieved by incorporating pH/temperature-responsive polyelectrolyte microgels into the textile surface layer using UV irradiation. The aim of functionalization was to regulate polyester wettability according to ambient conditions by imparting stimuli-responsiveness from the microgel to the textile itself. Microgels consisted of pH/thermo-responsive microparticles of poly(N-isopropylacrylamide-co-acrylic acid) either alone or complexed with the pH-responsive natural polysaccharide chitosan. Scanning Electron Microscopy, X-ray Photoelectron Spectroscopy, ζ-potential measurements, and topographical analysis were used for surface characterization. Wettability of polyester textiles was assessed by dynamic wetting, water vapor transfer, and moisture regain measurements. One of the main findings showed that the polyester surface was rendered pH-responsive, both in acidic and alkaline pH region, owing to the microgel incorporation. With a marked relaxation in their structure and an increase in their microporosity, the functionalized textiles exhibited higher water vapor transfer rates both at 20 and 40 °C, and 65% relative humidity compared with the reference polyester. Also, at 40 °C, i.e., above the microgel Lower Critical Solution Temperature, the functionalized polyester textiles had lower moisture regains than the reference. Finally, the type of the incorporated microgel affected significantly the polyester total absorption times, with an up to 300% increase in one case and an up to 80% decrease in another case. These findings are promising for the development of functional textile materials with possible applications in biotechnology, technical, and protective clothin

Use of Opuntia ficus-indica (L.) Mill extracts from Brazilian Caatinga as an alternative of natural moisturizer in cosmetic formulations

ABSTRACT The aim of this work was the obtainment of Opuntia fícus-indica (L.) Mill extract for the development of cosmetic formulations and in vivo evaluation of its moisturizing effects. The formulations were tested for preliminary and accelerated stability. Organoleptic characteristics, pH values and rheological behavior were assessed. The evaluation of moisturizing efficacy of the emulsions formulated with 3.0% of Polyacrylamide (and) C13-14 Isoparaffin (and) Laureth-7 containing 1.0 and 3.0% of O. ficus-indica hydroglycolic extract (EHG001) was performed using the capacitance method (Corneometer(r)) and the transepidermal water loss - TEWL evaluation (Tewameter(r)). The emulsions formulated were stable, exhibiting pseudoplastic and thixotropic behavior. The results of evaluation of moisturizing efficacy showed increased skin hydration after five hours by mainly increasing the skin barrier effect. The formulations containing 1.0 and 3.0% of EHG001 enhanced the skin barrier effect by reducing TEWL up to four hours after application. The results observed suggest that O. ficus-indica hydroglycolic extract may act through a humectant and occlusion mechanism

Surfactant properties of low molecular weight phospholipids

Surface tensions, critical micelle concentrations (CMCs), contact angles on hydrophobic polyethylene, and foaming characteristics of phosphatidic acids, phosphatidylcholines, phosphatidylethanolamines, and phosphatidylglycerols were measured to determine their suitability as substitutes for traditional surfactants. These phospholipids have fatty acid chains of 5 to 12 carbon atoms, a range over which they are soluble at room temperature. Their surface tensions decrease with increasing concentrations until their CMCs are reached, above which their plateau surface tensions are as low as 21 mN/m, indicating excellent surface activities. In general, plateau surface tensions decrease with increasing chain length within each phospholipid type. The classical relationship for In CMC vs. chain length is followed with slopes typical of anionic surfactants for phosphatidic acids and phosphatidylglycerols and resembling zwitterionic surfactants for phosphatidylcholines and phosphatidylethanolamines, consistent with the charge on the hydrophilic group. The wetting capabilities of aqueous solutions on polyethylene are good and foam heights and stabilities are high, the latter two properties being comparable to traditional anionic (sodium dodecylsulfate) and nonionic (octylphenol polyethoxylate) surfactants. Some anomalies are observed regarding the effect of chain length on wetting and foaming, probably due to the depletion effect. Many phospholipids slowly degrade in aqueous solution. We conclude that short-chain phospholipids exhibit excellent surfactant properties and may be useful in many applications.This is a post-print of an article from Journal of Surfactants and Detergents, 8, no. 1 (2005): 65–72, doi: 10.1007/s11743-005-0332-8.</p

Stability studies of cosmetic emulsions prepared from natural products such as wine, grape seed oil and mastic resin

An attempt was made in this study to use diluted wine as the aqueous phase and grapeseed oil as the oil phase for the preparation of oil-in-water cosmetic emulsions. Two monovarietal wines of Hellenic origin were used in this study; a red one from Sangiovese grapes and a white one from Muscat of Samos grapes. The oil-to-water ratio in the emulsions was 20:80 (v/v) and the wine concentrations in the aqueous phase were in the range of 5-100% (v/v). Glycerol monostearate was used as emulsifying agent. The only extra additive was mastic resin from Pistacia lentiscus var. Chia, which is reported to have healing and antibacterial properties. The study of the emulsion stability involved droplet size determinations and viscosity measurements for a period of sixty days. It was found that the optimum percentage of wine (red and white) in the aqueous phase of such emulsions is 20% (v/v) and of the mastic resin 2% (w/v)