Cationic Quaternary Ammonium Salt Research Articles

Reversibly Adhesive, Anti-Swelling, and Antibacterial Hydrogels for Tooth-Extraction Wound Healing.

Oral wound treatment faces challenges due to the complex oral environment, thus, sealing the wound quickly becomes necessary. Although some materials have achieved adhesion and sterilization, how to effectively solve the contradiction between strong adhesion and on-demand removal remains a challenge. Herein, a reversibly adhesive hydrogel is designed by free radical copolymerization of cationic monomer [2-(acryloyloxy) ethyl] trimethylammonium chloride (ATAC), hydrophobic monomer ethylene glycol phenyl ether acrylate (PEA) and N-isopropylacrylamide (NIPAAm). The cationic quaternary ammonium salts provide electrostatic interactions, the hydrophobic groups provide hydrophobic interactions, and the PNIPAAm chain segments provide hydrogen bonding, leading to strong adhesion. Therefore, the hydrogel obtains an adhesion strength of 18.67KPa to oral mucosa and can seal wounds fast within 10s. Furthermore, unlike pure PNIPAAm, the hydrogel has a lower critical solution temperature of 40.3°C due to the contribution of ATAC and PEA, enabling rapid removal with 40°C water after treatment. In addition, the hydrogel realizes excellent anti-swelling ratio (≈80%) and antibacterial efficiency (over 90%). Animal experiments prove that the hydrogel effectively reduces inflammation infiltration, promotes collagen deposition and vascular regeneration. Thus, hydrogel as a multi-functional dressing has great application prospects in oral wound management.

Quaternized chitosan-based organic-inorganic nanohybrid nanoparticles loaded with prothioconazole for efficient management of fungal diseases with minimal environmental impact

Poor foliar deposition and retention of pesticides results in serious pesticide residues and environmental pollution. Organic-inorganic hybridized nanoparticles (OIHN), combining the advantages of organic and inorganic materials, can be used as carriers to load pesticides for efficient and safe application. Herein, a novel multifunctional OIHN composed of mesoporous silica nanoparticles (MSNs) and cationic chitosan quaternary ammonium salt (HACC) was constructed and used as a delivery system for prothioconazole (PTC). The resultant PTC@MSNs-HACC exhibited a remarkable loading capacity of 39.07 wt% and demonstrated enhanced PTC release (31.47 %) under alkaline conditions. The UV-shielding properties of MSNs efficiently shielded PTC from photodegradation, increasing its photostability by over threefold. The strong positive charge of HACC conferred excellent adhesion of PTC@MSNs-HACC to fungal cell membranes, leading to high deposition on wheat leaves with improved rain-wash resistance (increased by 30 %). Consequently, PTC@MSNs-HACC (EC50: 12.48 mg/L) exhibited superior wheat scab control compared to PTC emulsifiable concentrate (EC50: 28.49 mg/L). Additionally, PTC@MSNs-HACC displayed excellent uptake and transport in plants, ensuring plant safety and reducing toxicity to zebrafish by >1-fold. The potential application of the developed PTC@MSNs-HACC in agricultural production holds significant promise and is anticipated to find widespread use in the future.

The comparison of polymerization activity of typical cationic quaternary ammonium salt monomers

AbstractThe cationic water‐soluble polymers, which are widely used in many areas such as papermaking and separation process, are typically synthesized through polymerization of cationic monomers represented by quaternary ammonium salt. In this work, the polymerization reaction kinetics of three typical quaternary ammonium salt cationic monomers including acryloyl oxygen ethyl trimethyl ammonium chloride (DAC), methyl acryloyl oxygen ethyl trimethyl ammonium chloride (DMC), and methyl acrylamide propyl trimethyl ammonium chloride (MAPTAC) was examined by using the dilatometer method. The results showed that the polymerization rate of all three monomers increased with the increase of initiation temperature, monomer concentration, and initiator concentration. Under the same conditions, the polymerization activity of the three monomers followed the order: DAC > DMC > MAPTAC. The activation energies for the polymerization reaction under the specified conditions were EaDAC = 138.97 kJ/mol, EaDMC = 141.24 kJ/mol, and EaMAPTAC = 226.97 kJ/mol, respectively. The polymerization rate equations were RpDAC = k1[M]4.25[I]0.51, RpDMC = k2[M]3.77[I]0.50, and RpMAPTAC = k3[M]3.30[I]0.49. The polymerization activity of the monomers may be influenced by electronic effects and steric hindrance of the monomer structure. This work has provided a theoretical and experimental foundation for the actual work of structural design and preparation of cationic water‐soluble polymers.

Polyelectrolyte Complex Hydrogels from Controlled Kneading and Annealing-Induced Tightly Wound and Highly Entangled Natural Polysaccharides.

Hydrogels usually are fabricated by using monomers or preexisting polymers in precursor solutions. Here, a polyelectrolyte complex biohydrogel (Bio-PEC hydrogel) made from a precursor dough, by kneading, annealing, and crosslinking the dough of two oppositely charged polysaccharides, cationic chitosan quaternary ammonium salt (HACC) and anionic sodium hyaluronate (HA), photoinitiator (α-ketoglutaric acid), crosslinker glycidyl methacrylate (GMA), and water of very small quantity is reported. Controlled kneading and annealing homogenized the dough with respect to transforming randomly distributed, individual polymer chains into tightly wound double-stranded structures, which, upon UV irradiation, covalently sparsely crosslinked into a highly entangled network and subsequently, upon fully swollen in water, results in Bio-PEC hydrogel, HACC/HA, exhibiting near-perfect elasticity, high tensile strength, and high swelling resistance. Via the same kneading and annealing, tetracarboxyphenylporphyrin iron (Fe-TCPP) metal nanoclusters are incorporated into HACC/HA to obtain photocatalytic, antibacterial, and biocompatible Bio-PEC hydrogel composite, Fe-TCPP@HACC/HA. Using SD rat models, the efficacy of Fe-TCPP@HACC/HA in inhibiting Escherichia coli (E. coli) growth in vitro and the ability to promote wound healing and scar-free skin regeneration in vivo, or its high potential as a wound dressing material for biomedical applications are demonstrated.

Quaternary Ammonium Salts of Cationic Lipopeptides with Lysine Residues — Synthesis, Antimicrobial, Hemolytic and Cytotoxic Activities

Ultrashort cationic lipopeptides (USCLs) and quaternary ammonium salts constitute two groups of cationic surfactants with high antimicrobial activity. This study aimed to investigate the influence of quaternization of the amino group of the lysine side chain in USCLs on their antimicrobial, hemolytic and cytotoxic activities. To do this, two series of lipopeptides were synthesized, USLCs and their quaternized analogues containing trimethylated lysine residues — qUSCLs (quaternized ultrashort cationic lipopeptides). Quaternization was performed on a resin during a standard solid-phase peptide synthesis with CH3I as the methylating agent. According to our knowledge, this is the first study presenting on-resin peptide quaternization. The lipopeptides were tested for their antibacterial and antifungal activities against the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella aerogenes) bacteria and Candida glabrata yeast-like fungus. Most of the compounds proved to be active antimicrobial agents with enhanced activity against Gram-positive strains and fungi and a lower against Gram-negative species. In addition, the antimicrobial activity of lipopeptides was increasing with an increase in hydrophobicity but qUSCLs exhibited usually a poorer antimicrobial activity than their parent molecules. Furthermore, the toxicity against red blood cells and human keratinocytes was assessed. It’s worth emphasizing that qUSCLs were less toxic than the parent molecules of comparative hydrophobicity. The results of the study proved that qUSCLs can offer a higher selectivity to pathogens over human cells than that of USCLs. Last but not least, quaternization of the peptides could increase their solubility and therefore their bioavailability and utility.

A silicone with one quaternary ammonium salt and three N-halamine sites in the repeating unit for improved antibiotic ability on submicrospheres

A silicone containing one cationic quaternary ammonium salt (QAS) and three N-halamine sites in the repeating unit was developed on SiO2 submicron spheres for better antibacterial performance, larger bactericidal area and easier recyclability. Briefly, a precursor (NDAM) with high content of N-halamine was prepared by the amidation reaction. Then, a SiO2@NDA nanocomposite was synthesized. Chlorination of the three imide NH bonds in the repeat unit finalized the synthesis of the bactericidal silicone (SiO2@NDA-Cl). The synthetic steps and products were characterized and the effect of the contents of NDAM in copolymer on antibacterial activity were systematically assayed. The SiO2@NDA-Cl showed higher deactivation abilities against both E. coli and S. aureus compared with their counterparts that contained only one cationic center or one N-halamine. This study has theoretical and practical application value for the development of new antibacterial materials.

CO2 Adsorption Based on Porphyrin Based Porous Organic Polymers

In order to efficiently catalyze the cycloaddition reaction of CO2 and epoxy alkanes under mild environment and no catalyst, this paper designed and synthesized two kinds of porphyrin based porous organic polymers—porphyrin based porous organic polymer containing carboxyl group (ppop-cooh) and porphyrin based porous organic polymer containing quaternary ammonium salt ion pair. Quaternary ammonium salt cation anion pair nucleophilic groups and metal active centers were introduced into the polymer by pre- and post-modification respectively. The chemical structure and pore structure of the polymer were characterized by infrared spectroscopy and physical adsorption instrument, and its effect as a catalyst on the cycloaddition reaction of CO2 and epoxy alkanes was studied. From the results, it is demonstrated that the two polymers had a multistage pore structure with a specific surface area of 302 m2/g-514 m2/g. The synergistic effect of Lewis acid metal ions, nucleophiles and multistage pore structure in the polymer significantly promotes the cycloaddition reaction between CO2 and epoxy alkanes. Under mild conditions (80°C, 0.3 MPa, 24h), the selectivity and conversion of the reaction reach more than 99%. The polymer is repeated for many times. After use, it still has good catalytic performance.

Study on production of cation asphalt emulsifier for micro-surfacing by using sulfomethylated lignin

This paper describes the research achievement in manufacturing the cation asphalt emulsifier for micro-surfacing using an eco-friendly material which is rich in resources and low in production cost. This material is alkali lignin which used to be treated as wastes during the processing of wood and the cation asphalt emulsifier for micro-surfacing made from this is sulfomethylated lignin quaternary ammonium salt cation emulsifier. This emulsifier is synthesized through sulfomethylation and quaternary-ammonization of alkali lignin so as to allow the emulsifier molecule to contain two hydrophilic groups inside it. Newly developed cation emulsifier is widely used for micro-surfacing for its high emulsifying power and slowly-disintegrable and fast-setting ability.

Biodegradable and Cytocompatible Hydrogel Coating with Antibacterial Activity for the Prevention of Implant-Associated Infection.

Implant-associated infection (IAI) caused by pathogens colonizing on the implant surface is a serious issue in the trauma-orthopedic surgery, which often leads to implant failure. The complications of IAI bring a big threat to the clinical practice of implants, accompanied by significant economic cost and long hospitalization time. In this study, we propose an antibiotics-free strategy to address IAI-related challenges by using a biodegradable and cytocompatible hydrogel coating. To achieve this, a novel hydrogel system was developed to combine the synergistic effects of good cell affinity and antibacterial properties. The hydrogel material was prepared by modifying a photocross-linkable gelatin-based polymer (GelMA) with cationic quaternary ammonium salt (QAS) groups via a mild and simple synthesis procedure. By engineering the length of the hydrophobic carbon chain on the QAS group and the degree of functionalization, the resulting GelMA-octylQAS hydrogel exhibited an integration of good mechanical properties, biodegradability, excellent bactericidal activity against various types of bacteria, and high cytocompatibility with mammalian cells. When coated onto the implant via the in situ cross-linking procedure, our hydrogel demonstrated superior antimicrobial ability in the infective model of femoral fracture of rats. Our results suggest that the GelMA-octylQAS hydrogel might provide a promising platform for preventing and treating IAI.

Preparation of degradable amphoteric surfactant and property evaluation of clean fracturing fluid

AbstractThe main agent of clean fracturing fluid, cationic quaternary ammonium salt surfactant, is difficult to degrade in natural conditions because of its long alkyl chain. In this study, a biodegradable amphoteric surfactant, stearate sulfobetaine (SESB), was synthesized by esterification of long‐chain stearic acid and N,N‐dimethyl ethanolamine followed by quaternization to serve as the main agent of clean fracturing fluid. The structure of the synthetic degradable surfactant was verified by infrared and 1H‐nuclear magnetic resonance spectroscopies. In addition, a series of indoor performance evaluations were carried out, including shear resistance, viscoelasticity, sand carrying capacity, and gel‐breaking performance. A series of experimental evaluations showed that the clean fracturing fluid prepared with 2% SESB and 0.4% EDTA‐4Na had an excellent comprehensive performance. The apparent viscosity was higher than 50 mPa s at 80°C for a shear rate of 170 s−1. It has good heat and shear resistance performance. In addition, the system processed high shear stability and recovery at room temperature. According to the viscoelastic test, the system mainly relies on elasticity to carry sand. The static settling velocity of sand was 0.042 mm/s under high‐temperature conditions of 95°C.

Preparation of a novel zwitterion flocculant with the characteristics of quaternary ammonium salt cation and dithiocarbamate anion and its application in produced water treatment

In this paper, a novel flocculant with the characteristics of both quaternary ammonium salt cation and dithiocarbamate anion was synthesized. Firstly, a cationic polymer having secondary amine side groups was synthesized by using cationic monomer and diallyl amine (DAA) as monomers via aqueous solution polymerization, and then the secondary amine was modified by carbon disulfide (CS2) to prepare the zwitterion flocculant. By using the oil removal as index, the effects of cationic monomer type, monomer concentration, mass ratio of cationic monomer to DAA, initiator concentration, polymerization temperature and time on the copolymerization results were investigated. The recommended rational condition was as follows: cationic monomer was methacryloxyethyltrimethyl ammonium chloride (DMC), monomer concentration was 50 wt%, mass ratio of DMC:DAA = 4:1, initiator was ammonium persulfate (APS) and its concentration was 0.4 wt%, and polymerization temperature was 60 °C for 8 h. The zwitterion flocculant obtained at the recommended condition had a removal of 99.5% at the dosage of 300 mg/L for produced water obtained from an offshore oilfield. In addition, the flocculation mechanism of the zwitterion flocculant was studied. According to the results of zeta potential measurement and floc morphology, it can be found that the quaternary ammonium salt unit in the zwitterion flocculant can bridge and flocculate oil droplets by destroying the stability of oil droplets in produced water through electrostatic neutralization, while the dithiocarbamate unit can interact with Fe2+ in produced water to form a network structure to catch flocculated oil droplets, and the synergistic effect of quaternary ammonium salt unit and dithiocarbamate unit is helpful for achieving the good flocculation result. The results provide a new selection for produced water treatment.

Surface modification of titanium implants by pH-Responsive coating designed for Self-Adaptive antibacterial and promoted osseointegration

The development of responsive antibacterial implants is of high significance for the treatment of implant-associated infections. In this study, a self-adaptive antibacterial Ti-based implant with pH-sensitive coating was flexibly designed and constructed, with the dual functions of antibacterial and promoted osseointegration. The pH-sensitive antibacterial copolymer containing cationic quaternary ammonium salts (QAs) and carboxyl groups was firstly synthesized. Then, the prepared copolymer was coated on the surface of Ti metal by a simple layer-by-layer (LBL) self-assembly method to construct an antibacterial coating. The surface charge reversal was caused by the acidic microenvironment induced by the infected bacteria. The positively charged QAs possessed excellent antibacterial property against E. coli and S. aureus in vitro. The negatively charged carboxyl groups promoted the adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells in vitro. And the results of a S. aureus infection rat model further confirmed that the coated screws possessed good abilities of antibacterial and anti-inflammatory of implantation, and showed good osteointegration performance compared with the control ones. This strategy of self-adaptive antibacterial coating will provide a potential application for the prevention of Ti implant-associated bacterial infections.

WITHDRAWN: Study on cold-mix cement asphalt emulsion concrete by using lignin quaternary ammonium salt cation asphalt emulsion

Abstract The paper analyzed and compared the structure formation process of cement asphalt emulsion mixture made from anion asphalt emulsion, that has been in use before, with that of cement asphalt emulsion mixture made from cation asphalt emulsion, and based on the results of such analysis and comparison, was produced lignin quarternary ammonium salt cation asphalt emulsion and was determined the mixing ratio of the cold-mix cement asphalt emulsion concrete which is made from this.

Modification of cotton fabrics with 2-diethylaminoethyl chloride for salt-free dyeing with anionic dyes

A chemical modification of cotton fabrics by 2-diethylaminoethyl chloride (DEAE-Cl) was achieved, and the resulted cotton fabrics demonstrated salt-free dyeing properties with anionic dyes. Nucleophilic property of hydroxyl groups in cotton cellulose was enhanced under alkaline conditions and could react with DEAE-Cl, a chemical possessing both nucleophilic and electrophilic sites. The monolayered DEAE-grafted cotton cellulose could further react with DEAE-Cl to form multiple cationic quaternary ammonium salts (denoted as DEAE@Cotton), which are highly interactive with anionic dye molecules. The strong electrostatic interactions between the DEAE@Cotton and the dyes eliminated the use of inorganic salts in cotton dyeing process. The chemical structure and property of DEAE@Cotton were characterized and compared with untreated cotton. The DEAE@Cotton can be dyed in a salt-free system, and the dye exhaustion was faster than the conventional dyeing method due to the robust electrostatic interactions of the fabrics with anionic dyes. The dyed fabrics demonstrated outstanding color fastness under repeated washing, light exposure, and crocking. The dye adsorption process on DEAE@Cotton follows Langmuir isotherm model (R2 = 0.9667). The mechanism of enhanced dyeability was experimentally proved by treating the fabric with other anionic dyes in a salt-free system, proving the process to be environmentally friendly and cost-effective.Graphic abstract

Improved methane storage capacity of methane hydrate promoted by vesicles from carboxylate surfactants and quaternary ammonium

The maximum methane storage capacity (MSC) is of critical importance of methane hydrate to store methane. This paper reports the effects of vesicle solutions, formed through combination of carboxylate surfactants with cationic quaternary ammonium salt including hydroxypropyl trimethyl ammonium chloride chitosan (HACC) or dodecyl trimethyl ammonium chloride (DTAC), on the formation of methane hydrate. It was found that vesicles could raise the maximum MSC of hydrate by about 10 (V/V, the volume of methane stored by one volume of hydrate) at appropriate anion and cation concentrations. For example, at 800 ppm (parts per million) of sodium laurate (SL) and 600 ppm of HACC concentrations, the formed vesicles could elevate the maximum capacity to 151 V/V, 5.3% higher than that of sodium laurate alone. The vesicles formed could increase the maximum MSC, from 136 V/V to 147 V/V by sodium oleate (SO) and HACC, 145 V/V to 153 V/V by sodium decanoate (SD) and HACC and 137 V/V to 149 V/V by SO and DTAC. The reason for the enhancement is that the large hydrophobic space of the vesicles could solubilize methane molecules and facilitate them to contact with water molecules.

Impacts of degree of substitution of quaternary cellulose on the strength improvement of fiber networks

The degree of substitution (DS) of cellulose derivative is significantly associated with its properties. In this paper, a series of quaternary cellulose (QC) samples with different DS (ranging from 0.16 to 0.51) were synthesized with assistance of microwave and their relationship with strength improvement of fiber networks was investigated systematically. QCs were characterized by elemental analysis, FT-IR, 1H NMR, and TGA, etc. The results showed that the cationic quaternary ammonium salt group was successfully grafted onto the backbones of cellulose chains and the thermal stability was associated inversely with the DS of QCs. However, the results of strength test for the fiber networks from secondary fiber of old corrugated containers showed that the tensile and burst strength was enhanced by addition of QCs, and their performance was positively correlated their DS. The best result achieved in this investigation was in the case of QC with DS of 0.51, with increments of tensile and burst strength 6.17% and 11.68%, respectively, at a dosage of 1.0 wt% based on oven-dry pulp. This investigation highlights the importance of DS of QC to its application in strength improvement for fiber networks.

Effects of cationic modifier type on the structure and morphology of organo-montmorillonite and its application properties in a high-temperature white oil system

Three types (eight modifiers with three radical groups) of cationic modifiers aliphatic quaternary ammonium salts (AlQAS), aromatic quaternary ammonium salts (ArQAS), and polyoxyethylene quaternary ammonium salts (PoQAS), were used to modify montmorillonite (Mt) and prepare cationic-organo-montmorillonites (COMt). COMt was characterized by X-ray diffraction, scanning electron microscopy, contact angle, thermogravimetry, optical microscopy, gel volume, viscosity, and thixotropy to explore modifier type effects on the structure, morphology, and properties of COMt, as well as investigate the application properties in white oil system. The results show that eight cationic modifiers all entered the Mt. layer to form intercalated COMt. The modifier type significantly influences the structure, morphology, and properties of the obtained COMt and the application properties in white oil system. The basal spacing of PoQAS COMt (d001 = 4.33 nm ~ 5.28 nm) was the larger than ArQAS COMt (d001 = 3.14 nm ~ 3.60 nm) and AlQAS COMt (d001 = 2.91 nm ~ 3.66 nm). The morphologies of the three types of COMt lamella were all in a loose state. The order of COMt lamellar loosening degree with the same chain length was PoQAS COMt > ArQAS COMt > AlQAS COMt. The thermal stability and lipophilicity of the COMt powders were consistent with the morphology results. In the white oil system at 180 °C, XRD results showed that the thermal stability of PoQAS COMt was the best (maintaining the structure of PoQAS COMt and no Mt. generation), followed by ArQAS COMt, and AlQAS COMt had the worst thermal stability. The viscosity and thixotropy of three types COMt was ArQAS COMt better than PoQAS COMt and AlQAS COMt, PoQAS COMt better than AlQAS COMt. Research also showed that the steric hindrance, electropositivity of the modifier molecule, and modifiers' thermal stability are positively related to the thermal stability of COMt in white oil. This work provides a basis and other ideas in understanding the relationships between radical groups types, the structures of quaternary ammonium salts, the thermal stability of COMt, and selecting and developing new modifiers.

ЭПОКСИДНЫЕ АНТИФРИКЦИОННЫЕ ПОКРЫТИЯ, НАПОЛНЕННЫЕ ОБРАБОТАННОЙ ПОВЕРХНОСТНО-АКТИВНЫМИ ВЕЩЕСТВАМИ ЗОЛОЙ РИСОВОЙ ШЕЛУХИ

The use of epoxy antifriction coatings can significantly reduce thermal stress in the friction zone and expand the coating working temperature interval while keeping high wear resistance. The paper considers the effect of non-activated and activated by surfactants silicate filler – rice husk ash on the physicochemical and mechanical properties of epoxy materials applied as antifriction coatings. All studied samples of rice husk ash, both initial and activated with surfactants, have an alkaline surface nature. The study identified that all cationic quaternary ammonium salts (QAS) reduce the pH of rice husk ash. At the same time, nonionic OXIPAV increases this indicator. Activation of the rice husk ash surface, both by the quaternary ammonium salts and aminosilanes, significantly reduces the porosity of this silicate. In this case, the average pore diameter does not change significantly, and their specific surface area decreases significantly, to a lesser extent, when activated by nonionic quaternary ammonium salts. The application of quaternary ammonium salts and aminosilanes in the amount of 33 % for activation of the surface of the investigated silicate filler reduces its modifying effect in epoxy compositions, regardless of the chemical structure of the surfactants used, which is not a typical effect. Therefore, the authors assumed that the suboptimal concentration of quaternary ammonium salts and aminosilanes was used. The study identified that the optimal concentration of 50 % alcohol solution of KATAPAV is 14.7–21 %. In this range of the QAS content, there is a significant increase in hardness (about 40 %), a slight decrease in wear (about 10 %), and a significant decrease in the coefficient of static friction (up to 2 times). At the same time, the authors observed an increase in adhesion to metal up to 3 times and bending strength up to 25 %. Thus, rice husk ash activated with an optimal amount of quaternary ammonium salts is an effective modifier of epoxy coatings, which improves their antifriction properties and increases wear resistance, hardness, strength, and adhesion characteristics.

Novel quat/di-N-halamines silane unit with enhanced synergism polymerized on cellulose for development of superior biocidability

A silane unit with enhanced synergism that is realized using one cationic quaternary ammonium salt (QAS) to draw anionic bacteria to two N-halamine functionalities was designed and polymerized on cellulose for superior biocidability. A monomer containing one tertiary amine, one amide N–H, and one imide N–H, was synthesized via alcoholysis of 3-triethoxysilylpropyl succinic anhydride with 2-(dimethylamino)ethan-1-ol and following esterification with 5-(4-hydroxyphenyl)hydantoin. The triethoxysilyl groups of the monomer were hydrolyzed to silanol groups to condense with counterparts in different hydrolyzates and with hydroxyl groups on cellulose to form a polymeric modifier. Each silane unit of the modifier has one QAS and two N-halamine functionalities (quat/di-N-halamines) after quaternization of the tertiary amine and chlorination of the amide and imide hydrogens. The resultant cellulose suppressed (7 logs) both Staphylococcus aureus and Escherichia coli within 3 min, demonstrating an enhanced synergism since the inactivation rate is faster than counterparts decorated with only N-halamine and with synergistic units of one cationic center and one N-halamine. The modifier exhibited promising stability and rechargeability toward washings, UV irradiation, and long-term storage. The proved enhanced synergism from the integration of one cationic center with multiple N-halamines directs the synthesis of more powerful biocides for developing antibacterial polymers.

Cationic quaternary ammonium salt-catalyzed LED-induced living radical polymerization within situhalogen exchange

Cationic quaternary ammonium salts were employed as organocatalysts for light-emitting diode (LED)-induced living radical polymerization (LRP) with thein situhalogen exchange of methacrylate monomers.