Impact of Processing Conditions on Rheology, Tribology and Wet Lubrication Performance of a Novel Amino Lipid Hair Conditioner

The objective of this work was to carry out a comprehensive evaluation of the performance of a novel cationic amino lipid surfactant, Brassicyl Valinate Esylate (BVE), in contrast to conventional alkyl quaternary ammonium surfactants (quats), through a study of the effects of process mixing speed on its overall rheological, tribological and wet lubrication performance in comparison to BTAC and CTAC, two cationic surfactants widely used in cosmetics. The major cosmetic application of cationic surfactants is in the preparation of hair conditioners. Hence, this analysis was done firstly by conducting tensile combing tests to evaluate reduction in wet lubrication which translates to conditioning performance. The combing results serve as a testing metric that adequately corresponds to consumer perception of conditioned hair. To correlate this technically, yield stress measurements were conducted to establish rheologic profiles of the conditioner formulations, and in vitro tribological testing of the emulsion systems between two steel surfaces were done to technically simulate the spreading and rubbing of conditioner on the hair. The effect of processing conditions on the formulations was then evaluated. BVE was found to be an effective conditioning surfactant suitable as an eco-friendly replacement for BTAC and CTAC in hair conditioner formulations. The results showed that higher shear mixing rates during formulation lead to poorer performance effects evident through decreased yield stress values, lower percentage reduction in combing force and a higher coefficient of friction.

The Use of Catalytic Amounts of Selected Cationic Surfactants in the Design of New Synergistic Preservative Solutions

Preservation using combinations of antibacterial molecules has several advantages, such as reducing the level of usage and broadening their antimicrobial spectrum. More specifically, the use of quaternary ammonium surfactants (QAS)—which are profusely used in hair care products and some are known as efficient antimicrobial agents—is limited due to some potential cytotoxicity concerns. This study shows that the concentration of some widely used cosmetic preservatives can be decreased when combined with very small quantities of QAS, i.e., Polyquaternium-80 (P-80) and/or Didecyldimethylammonium chloride (DDAC). The antimicrobial activity of their mixtures was first evaluated by determining the minimum inhibitory concentration (MIC) before and after the addition of QAS. Following up on this finding and targeting an ultimate consumer friendly antimicrobial blend, yet with optimal safety, we chose to utilize the food-grade preservative Maltol as the main natural origin antimicrobial agent mixed with minimum concentrations of QAS to improve its moderate antimicrobial properties. The preservatives were tested for MIC values, challenge tests and synergy using the fractional inhibitory concentration index (FICI). The antimicrobial efficacy of Maltol was found to be synergistically improved by introducing catalytic amounts of P-80 and/or DDAC.

Application of Quaternary Ammonium Compounds as Compatibilizers for Polymer Blends and Polymer Composites—A Concise Review

A wide variety of quaternary ammonium compounds (QACs) have escalated the attraction of researchers to explore the application of QACs. The compounds have frequently been synthesized through alkylation or quaternization of tertiary amines with alkyl halides. Recently, QACs have been applied to compatibilize polymer blends and polymer composites in improving their thermo-mechanical properties. This concise review concentrates on the application of two types of QACs as compatibilizers for polymer blends and polymer composites. The types of QACs that were effectively applied in the blends and composites are quaternary ammonium surfactants (QASs) and quaternary ammonium ionic liquids (QAILs). They have been chosen for the discussion because of their unique chemical structure which can interact with the polymer blend and composite components. The influence of QASs and QAILs on the thermo-mechanical properties of the polymer blends and polymer composites is also described. This review could be helpful for the polymer blend and polymer composite researchers and induce more novel ideas in this research area.

Hydrocracking of Coconut Oil on the NiO/Silica-Rich Zeolite Synthesized Using a Quaternary Ammonium Surfactant

NiO/silica-rich zeolite catalysts were used for coconut oil hydrocracking. The catalyst was prepared with a mixture of Na2SiO3, Al(OH)3, NaOH, and quaternary ammonium surfactants. The surfactant was varied of types like as tetrapropylammonium bromide (TPAB) and cetyltrimethylammonium bromide (CTAB). The acidity of the silica-rich sodalite zeolites enhances with the increase in nickel oxide added through a wet impregnation. The hydrocracking process was carried out by a semi-batch method. Liquid products were analyzed using GC-MS. The results showed that the addition of surfactants increased the catalyst surface area and acidity. Meanwhile, the presence of nickel oxide increases the acidity of the catalyst. The hydrocracking results showed an increase in gas products when the surface area was high, i.e., 23.781% in silica-rich sodalite zeolite without template (Z), 32.68% in silica-rich sodalite zeolite with tetrapropylammonium (ZTPA), and 39.673% in silica-rich sodalite zeolite with cetyltrimethylammonium (ZCTA). The presence of NiO increased the liquid product and the selectivity of the bioavtur fraction (C10-C15), where the highest percentage of liquid product was 60.07% at NiO/ZTPA.