Yong Chen

The adjustment of the ratio of synergistic components in a hybrid unit of a polymer is demonstrated as a strategy for even better biocidability. Briefly, an N ‐halamine precursor, 1‐(3‐hydroxypropyl)‐1,3,5‐triazinane‐2,4,6‐trione, was synthesized through nucleophilic substitution between 1,3,5‐triazinane‐2,4,6‐trione and 3‐chloro‐1‐propanol. Itaconic anhydride was then used to bridge 2‐(dimethylamino)ethan‐1‐ol and the precursor via alcoholysis and esterification. The tertiary amine and CC bond of the esterification compound underwent reactions with 1‐chlorohexane and trimethoxysilane through quaternization and hydrosilylation, respectively. The molecules of the hydrosilylation compound were hydrolyzed and then crosslinked into a polysiloxane layer with pendants of one quaternary ammonium salt and two NH bonds on cellulose via dehydrocondensation. Following chlorination of the NH bonds to NCl counterparts, the cellulose was coated with a 96 nm layer containing the target hybrid units. Time‐kill assessments revealed that the quaternary ammonium salt and N ‐halamine structures functioned synergistically, resulting in greater efficacy than a previously reported 1:1 combination and hence demonstrating a better antibacterial synergism. Antibacterial durability and rechargeability on cellulose were both encouraging owing to the robust three‐dimensional crosslinked polysiloxane and the stable cyclic N ‐halamine. This study proposes a tactic for better antibacterial synergism through the increase of the proportion of N ‐halamine in a hybrid unit.

A silicone carrying combined functionalities of different mechanisms and physiochemical properties is synthesized as a strategy for faster and broader bacterial eliminations. Briefly, ring‐opening alcoholysis of succinic anhydride with 2‐dimethylaminoethanol and subsequent esterification of the alcoholysis product with 5‐(4‐hydroxyphenyl)imidazolidine‐2,4‐dione produced a structure with one tertiary amine and two hydantoinyl NH bonds. The tertiary amine was quaternized with 3‐chloro‐1‐propanol whose OH was then alcoholyzed with SiH of poly(methylhydrosiloxane). The polymeric product was interpenetrated into cotton at 30 MPa and 50°C in supercritical CO₂ and treated with tert‐butyl hypochlorite to chlorinate its hydantoinyl NH bonds, forming a 78 nm biocidal layer of silicone with quaternized hydantoin‐based N‐chloramines. Antibacterial tests showed that the quaternary ammonium salt and two hydantoin‐based N‐chloramines act synergistically due to their complementary features, killing both Staphylococcus aureus and Escherichia coli much more efficiently than each functionality. More importantly, the ratio of N‐chloramine to quaternary ammonium salt of 2:1 herein also provided higher efficacy than a reported counterpart with a 1:1 ratio. Biocidability of the modified cotton had promising stability and rechargeability, which indicates that supercritical interpenetration produced a durable interfacial layer without the necessity of chemical bonding.

‘On Water’‐promoted the three‐component tandem Michael addition/D−A cycloaddition reaction in 80 °C at 3 h has been developed without employing any catalyst and organic solvent. The process allows facile access to polycyclic N‐heterocycles derivatives contain indole and maleimide from easily accessible starting materials in moderate to high yields (up to 91 %). Compared with conventional reaction conditions, this reaction not only improves the reaction efficiency and rate but also minimizes the side reaction.

Cyclic N-halamines are highly antimicrobial, very stable, and not susceptible to bacterial resistance. A polysiloxane delivery vehicle was synthesized to deliver cyclic imide N-halamine onto cellulose via a benign and universal procedure that does not require a harmful solvent or chemical bonding. In brief, Knoevenagel condensation between barbituric acid and 4-hydroxybenzaldehyde furnished 5-(4-hydroxybenzylidene)pyrimidine-2,4,6-trione, whose phenolic O−H was subsequently reacted with the Si−H of poly(methylhydrosiloxane) (PMHS) via silane alcoholysis. The product of silane alcoholysis was interpenetrated into cellulose in supercritical CO₂ (scCO₂) at 50 °C, to form a continuous modification layer. The thickness of the modification layer positively correlated with interpenetration pressure in the experimental range of 10 to 28 MPa and reached a maximum value of 76.5 nm, which demonstrates the ability for tunable delivery, to control the loading of the imide N−H bond originating from barbituric acid unit. The imide N−H bonds on cellulose with the thickest modifier were then chlorinated into N−Cl counterparts using tert-butyl hypochlorite, to exert a powerful biocidability, providing ~7 log reductions of both S. aureus and E. coli in 20 min. The stability and rechargeability of the biocidability were both very promising, suggesting that the polysiloxane modifier has a satisfactory chemical structure and interlocks firmly with cellulose via scCO₂ interpenetration.

Mesoporous silica materials were synthesized using tetraethoxysilane (TEOS) as precursor and liquid crystals (LCs) formed in mixtures of cationic cetyltrimethylammonium bromide (CTAB) and anionic sodium dodecyl sulfate (SDS) with additions of NaBr and 1-hexanol as templates. For this purpose, the formation of LCs in the mixtures under different conditions was first studied. It was found that the additions of 1-hexanol and NaBr can synergistically weaken the electrostatic interaction between CTAB and SDS and promote the growth of the ordered assemblies, leading to the significant expansion of the LC phase areas in both SDS excess area and CTAB excess area, respectively. The effects of 1-hexanol concentrations, surfactant concentrations, and pH values on the phase diagram and hence the structures of LCs were subsequently studied. These LCs are well-structured templates for the syntheses of mesoporous silica materials that were characterized using nitrogen adsorption/desorption analysis and scanning electron microscopy (SEM). It was shown that 1-hexanol played an important role in the formation of LC templates and hence effectively improved the specific surface area and order of mesoporous materials. The BET specific surface area was high up to 937 m(2)/g and the average pore diameter increased to 2.5 nm when the total concentration of CTAB and SDS was 0.2 mol/L, the molar fraction of CTAB in the mixture was 0.82, the concentration of 1-hexanol was 0.4 mol/L, and pH value was 2. These studies shed light on the syntheses of mesoporous materials with large specific surface area and highly ordered structure for multiple applications.

In this study, a new surfactant compounding system was selected based on emulsifying performance. Finally, the prescription was made up of 0.5wt% oleate amide propyl betaine 0.1wt% octadecyl ammonium oxide. And its emulsification ability were systematically evaluated. At the same time, the emulsion types formed by different concentrations of surfactants was observed. The factors affecting emulsifying performance are analyzed. The research results obtained show that the compounding system has good emulsifying properties. All results reflect the fact that compounding system can expand their application range in different environment with various extents, which will benefit the design and use of compounding system.