The Role of Laundry Detergents in the Elements of Skin Pathogen

Background: The Corona pandemic fuelled up skin pathogen challenges in young and adults, the antimicrobial efficacy of laundry detergents could be considered particularly. However, no available data focusing on the form of laundry detergent, additives and conditions affect the antimicrobial efficacy. This study simulated washing procedures to investigate the antibacterial and antifungal activity of laundry detergents.Methods and Results: Mimic laundry procedures were performed to treat Gram-positive bacteria, Gram-negative bacteria and fungus, colony counting and propidium iodide staining were used to assess the antimicrobial activity. Powder detergent A, NaBO3*4H2O with the tetraacetylethylenediamine, 2Na2co3.3H2O with tetraacetylethylenediamine could achieve a > 5-log10 reduction of three microbial colony generation. Anionic surfactant sodium dodecylbenzene sulphonate (SDBS) group had the strongest fluorescence intensity in three microbial propidium iodide staining.Conclusions: Powder form laundry detergents are superior to liquid form, peroxide-based bleaches and bleach activator in solid form, the solid surfactants with matched PH and alkyl chain length showed a considerable antimicrobial effect.

Synthesis of Novel Cationic Bleach Activator, N-[4-(N,N,N)-Triethylammoniumchloride- Butanoyl] Butyrolactam, for Cellulose : Optimization and Theoretical Limitations

Activated bleach systems have the potential to produce more efficient kinetically potent bleaching systems through increased oxidation rates with reducing energy cost, saving time and, hence, causing less cellulose polymer chains damage or degradation than conventional hot peroxide bleaching. In this study, a novel cationic bleach activator, N-[4-(N,N,N)-triethylammoniumchloride- butanoyl] butyrolactam (TBUCB), was synthesized and applied for hot peroxide bleaching to determine the optimum bleaching conditions and theoretical limitations of TBUCB for low temperature bleaching of cellulose. First principles density functional theory (DFT) calculations were performed to elucidate the reaction mechanism via identifying plausible transition state(s) of the nucleophilic attack of perhydroxyl anion (HOO-) with different carbonyl carbons and identifying the advantages and limitations of TBUCB activator for hydrogen peroxide bleaching for cellulose. The results obtained showed that whiteness index greater than 80 for cellulose can be achieved by using activated H2O2-TBUCB bleaching system at lower temperature, providing reduced energy cost while maintaining the integrity of cellulose polymer chains.

An Eco-Friendly Approach to Low-Temperature and Near-Neutral Bleaching of Cotton Knitted Fabrics Using Glycerol Triacetate as an Activator

Near-neutral bleaching of cotton fabrics at low temperature is of great importance for saving energy and ecological friendliness in textile industry. In this work, glycerol triacetate (GT) was investigated as an activator of hydrogen peroxide (H2O2) for low temperature bleaching of cotton knitted fabrics, and satisfactory whiteness was obtained. The bleaching properties of H2O2/GT system for cotton was assessed by the CIE whiteness index, H2O2 decomposition rate, concentration of generated peracetic acid (PAA) and bursting strength. Possible factors affecting the performance of H2O2/GT bleaching system were discussed in detail. Adding only 10 mmol/L GT to the hydrogen peroxide solution (60 mmol/L) to bleach cotton knitted fabrics at 60 ℃ for 60 min, the WI was significantly increased from 52.09 to 68.92. By using benzenepentacarboxylic acid as a fluorescent probe for hydroxyl radical (HO·) detection, it was found that GT could clearly promote HO· generation and the concentration of HO· closely related to the WI of cotton fabric. Furthermore, the bleaching mechanism of H2O2/GT system to cotton was proposed by exploring the relationship between WI and HO· concentration. As a bleach activator, GT has more economical benefits and better solubility in water than that of TAED. The H2O2/GT system may provide a cost-effective and environmentally friendly approach as alternative to conventional alkaline high-temperature bleaching of cotton.

Influence of Bleach Activators in Removing Different Soils from Cotton Fabric

The influence of adding Sodium Perborate Tetrahydrate (NaPB) and tetraacetylethylenediamine (TAED) on the efficiency of removing soils from cotton fabric was evaluated in the study. NaPB as inorganic peroxide and TAED as a bleach activator were added to a commercial washing powder agent. Four standard soils applied on cotton fabric (EMPA standard soiled fabrics) were used in the study, i.e. 101 – carbon black/olive oil, 114 – red wine, 116 – blood/ milk/ink and 160 – chocolate. The washing of fabrics was conducted in accordance with the SIST EN ISO 105-C06 standard at 40, 60 and 90 °C in Launder-Ometer apparatus. The washing efficiency was evaluated by determining the CIE L* colour coordinates of the unwashed and washed fabric samples, and the difference in ΔL* colour coordinates among them. The results showed that NaPB and TAED improve the efficiency of washing for two standard soils, have no effect on one, and deteriorate the washing results of one standard soil.

Low Temperature Bleaching of Cotton with a Novel Cationic Activator

A new cationic bleach activator (CBA) N-[4-pyridmoniomethyl)benzoyl]caprolactam bromide (PBCB) was synthesized and evaluated in a hot peroxide bleaching process. The effects of time, temperature and the concentrations of hydrogen peroxide and activator on the bleaching of cotton fabric were investigated using an orthogonal experimental method. The optimal bleaching process of PBCB-activated peroxide system was 5g/L H2O2, 0.5g/L CBA, 40°Cand 45min dwell time under neutral pH, with which a whiteness equivalent to that of the conventional-bleaching system was achieved, but the PBCB system resulted in almost no fiber damage based on fabric strength.