Novel regenerable N‐halamine polymeric biocides. II. Grafting hydantoin‐containing monomers onto cotton cellulose

A novel cyclic‐amine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH) was synthesized with good yield by the reaction of allyl bromide with 5,5‐dimethylhydantoin (DMH), and was characterized by FTIR and ¹H‐NMR spectra. ADMH alone cannot be grafted onto other polymers. However, the presence of acrylonitrile markedly enhanced the ADMH graft yield onto cotton cellulose. The influence of reaction conditions on the graft copolymerization was investigated. After chlorine bleach treatment, hydantoin units in the grafted copolymers were easily transformed into N‐halamine structures. Grafted samples exhibited potent antibacterial activity against Escherichia coli, and the functional properties were shown to be durable and regenerable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 617–624, 2001     

N‐halamine‐modified polyglycolide (PGA) multifilament as a potential bactericidal surgical suture: In vitro study

In this study, new cationic homopolymer and anionic copolymer were synthesized, and deposited onto polyglycolide sutures using a layer‐by‐layer assembly technique. The coated sutures were rendered antibacterial by chlorinating with dilute solution of household bleach solution at pH 7. The chlorination treatment transformed the N? H groups of anionic copolymer into N‐halamine structures. The N‐halamine‐modified sutures were challenged with Staphylococcus aureus and Escherichia coli O157:H7 bacteria at different contact times. The suture with chlorine loading of 0.22% completely inactivated both bacterial strains in 30 min contact time. Fourier transform infrared spectroscopy, scanning electron microscopy, and analytical titration confirmed the successful deposition of the N‐halamine multilayers. The effect of layer‐by‐layer coatings of polyelectrolytes on the chlorine loading and antibacterial efficacy of sutures was evaluated. The straight‐pull and knot‐pull strength tests performed on the sutures reported slight decline in tensile properties after chlorination treatment. The in vitro hemolysis and cytocompatibility tests revealed that the N‐halamines‐based antibacterial sutures were biocompatible. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42483.     

Preparation and characterization of antimicrobial PVA hybrid films with N‐halamine modified chitosan nanospheres

Chitosan is a promising candidate as an antimicrobial agent in food packaging materials and biomaterials due to its biocompatibility, biodegradability, non‐toxicity and biocidal activity. In this study, chitosan derivatives, α‐(5,5‐dimethyl hydantoin amino)‐chitosan (CS‐HDH), were synthesized. The CS‐HDH nanospheres were prepared by ionic gelation method and characterized by SEM, FT‐IR, XRD, and TGA‐DTG. The prepared novel chitosan nanospheres in the range of 200–300 nm had good dispersibility. The CS‐HDH nanospheres were used to prepare antibacterial PVA hybrid films by solvent evaporation technique. The surface morphology and thermal property of hybrid films were measured by SEM, AFM, and TGA‐DTG. The results of antibacterial test showed that the hybrid film with 1.24 × 10¹⁸ atoms/cm² of active chlorine exhibited excellent antibacterial properties against Staphylococcus aureus and Escherichia coli O157:H7, and all of bacteria could be inactivated within 5 min. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44204.     

Antimicrobial N‐halamine coatings synthesized via vapor‐phase assisted polymerization

An N‐halamine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH), was synthesized by a Gabriel reaction of 5,5‐dimethylhydantoin and 3‐bromopropene. Antimicrobial coatings of poly[1‐(4,4‐dimethyl‐2,5‐dioxoimidazolidin‐1‐methyl)ethylene] were prepared on plasma‐treated PET fabrics via a vapor‐phase assisted polymerization (VAP) process using gasified ADMH as monomer. The coatings endow the PET fabrics with an antimicrobial efficiency greater than 80% for both Escherichia coli and Staphylococcus aureus after chlorination of the N‐halamine polymer with dilute bleach solution. The obtained antimicrobial effect has remarkable durability that can bear over 30 times of stringent laundering tests. Compared with other antimicrobial finishing methods, the VAP methodology offers great advantages in needless of organic solvents and small consumption of monomer. It has potential applications in a wide variety of fields such as hygienic clothing, underwear, socks, and medical textiles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41824.     

Antimicrobial silica and sand particles functionalized with an N‐halamine acrylamidesiloxane copolymer

The monomer 2‐acrylamido‐2‐methyl‐1‐(5‐methylhydantoinyl)propane (HA) was copolymerized with 3‐(trimethoxysilyl)propyl methacrylate (SL) and covalently attached onto silica gel and sand particles. As a result HASL copolymer‐grafted silica gel and sand particles (HASL SGPs and SPs) were obtained. These two types of HASL SGPs and SPs provided excellent biocidal efficacy against Gram positive S. aureus and Gram negative E. coli O157:H7 bacteria when the copolymer‐grafted particles were exposed to dilute sodium hypochlorite (household bleach) solution. In a flowing water application, seven logs of bacteria were inactivated within 10 s of contact time with the particles packed into a column. The treated particles also exhibited good washing and storage stabilities. The chlorine loss during extensive flow could be recovered by further exposure to dilute bleach solution. The antimicrobial particles have potential application for use in inexpensive disinfecting water filters for slow water flows. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43413.     

Preparation of antibacterial cellulose with s‐triazine‐based quaternarized N‐halamine

To reduce the neutral salt used in the textile finishing with s‐triazine derivatives, a novel s‐triazine‐based quaternarized N‐halamine precursor was synthesized by two simple steps and characterized by H‐NMR and FT‐IR. This compound can be effectively coated onto cellulose by nucleophilic substitution process without neutral salt. The treated cellulose was rendered with powerful biocidal efficacy after transferring to an N‐halamine structure by exposing to dilute sodium hypochlorite solution through the synergistic antimicrobial effect quaternary ammonium salt and N‐halamine. The chlorinated samples could inactivate 6‐logs of Staphylococcus aureus and Escherichia coli O157:H7 within 1 min and 5 min, respectively. In addition, about 50% of oxidant chlorine remained after 50 washing cycles and 30 days storage, and all of the lost active chlorines in the N‐halamine molecules recovered after exposing to bleach solution. With these advantages, the as‐prepared antimicrobial fabrics will have potential application, especially in the medical and healthcare textiles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44998.     

Novel regenerable N‐halamine polymeric biocides. III. Grafting hydantoin‐containing monomers onto synthetic fabrics

A novel cyclic‐amine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH) was synthesized and characterized. ADMH alone could not be grafted onto ordinary polymers. However, the presence of triallyl‐1,3,5‐triazine‐2,4,6(1H,3H,5H)‐trione (TATAT) remarkably enhanced the ADMH grafting yield onto synthetic fabrics. The influences of reaction conditions on the grafting copolymerization were investigated. After chlorine bleach treatment, hydantoin units in the grafted copolymers were transformed into N‐halamine structures. Treated samples exhibited potent antibacterial activity against Escherichia coli, and the functional properties were shown to be durable and regenerable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1517–1525, 2001     

Antimicrobial polyethylene terephthalate (PET) treated with an aromatic N‐halamine precursor,m‐aramid

A commercial m‐aramid as N‐halamine precursor has been coated onto polyethylene terephthalate (PET) fabric surface by pad‐dry‐curing process. The process is accomplished by padding the scoured PET fabric through the homogeneous m‐aramid solution, drying at 150°C for 3 min, and curing at 230°C for 3 min. The PET surface coated with m‐aramid was characterized using fourier transform infrared‐attenuated total reflection (FTIR‐ATR) spectroscopy, X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). FTIR exhibits new bands in the 1645 and 1524 cm^?1 regions as characteristic of m‐aramid bands, which indicate the PET fabric coated with m‐aramid. XPS results show a distinguishable peak at binding energy 398.7 eV, which confirms the nitrogen atom of m‐aramid on the PET surface. In addition, SEM image shows a layer of coating onto the PET surfaces, which demonstrates the presence of m‐aramid coating on the surface of the PET. After exposure to dilute sodium hypochlorite solution, exhibition of antimicrobial activity on the coated PET is attributed to the conversion of N‐halamine moieties from the N‐halamine precursor. The chlorinated PET showed high antimicrobial activity against Gram‐negative and Gram‐positive bacteria. The chlorinated PET coated with 10% m‐aramid exhibited about 6 log reductions of S. aureus and E. coli O157:H7 at a contact time of 10 and 30 min, respectively. Furthermore, the antimicrobial activity was durable and rechargeable after 25 wash cycles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Antimicrobial functionalization of poly(ethylene terephthalate) fabrics with waterborne N‐halamine epoxides

A water dispersible terpolymer of [2‐(methacryloyloxy)ethyl]trimethylammonium chloride, glycidyl methacrylate and hydantoinyl acrylamide was synthesized and coated on poly(ethylene terephthalate) fabrics through a pad‐dry‐cure procedure. The coatings were rendered biocidal upon exposure to dilute household bleach solution. The halogenated fabrics exhibited great antimicrobial functionality with about six logs inactivation of S. aureus and E. coli O157:H7 within only two min of contact time. Moreover, the coatings were found to be very stable against repeated washings and UVA light exposure. It was shown that [2‐(methacryloyloxy)ethyl]trimethylammonium monomer is very useful in preparing waterborne N‐halamines which can impart rechargeable, effective, and stable antimicrobial coatings to poly(ethylene terephthalate) fabrics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43088.     

Thiocarbohydrazide‐modified chitosan as anticorrosion and metal ion adsorbent

To explore the application of chitosan (CS) derivatives in anticorrosion and adsorption, thiocarbohydrazide‐modified chitosan (TCHECS) derivative was synthesized and characterized. The preliminary electrochemical measurements of the behaviors of 304 steel and Cu sheets in 2% HAc (v/v) containing TCHECS, chitosan (CS), and hydrazine cross‐linked epoxy‐N‐phthaloylchitosan (HECS) had been performed. The short‐term electrochemical tests show that the new compound can act as a mixed‐type metal anticorrosion inhibitor; its inhibition efficiency is 88% when the concentration was 30 mg/L. The preliminary adsorption studies for sorbents TCHECS and HECS on a metal ion mixture aqueous solution were also performed. The results show that TCHECS can absorb As (V), Ni (II), Cu (II), Cd (II), and Pb (II) efficiently at pH 9; the removal of the As (V), Ni (II), Cu (II), Cd (II), and Pb (II) are around 55.6–99.9%. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40671.     

Modified cellulose fibers prepared by the N‐methylmorpholine‐N‐oxide (NMMO) process

Cellulose fibers with modified properties have been prepared from cellulose solutions in N‐methylmorpholine‐N‐oxide (NMMO). Poly(ethylene oxide) as a hydrophilic modifier and polyethylene as a hydrophobic modifier were added to the spinning solution. Based on microscope examination and measurements of such properties of fibers as porosity, moisture absorption, water retention, and tensile strength, structural changes as well as physical and mechanical properties of the resultant fibers depending on the amount of modifier added to the spinning solution were analyzed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 907–916, 2002     

Synthesis and application to cellulose of reactive dye precursor of anti‐bacterial N‐halamine

To achieve textile dyeing and functional finishing in one process, a bleach‐resistant reactive dye precursor to anti‐bacterial N‐halamine was synthesised by reacting a type of dichlorotriazine reactive dye with 4‐amino‐2,2,6,6‐tetramethylpiperidine. The synthesised compound, which can be transformed to an N‐halamine molecule by exposure to dilute bleach solution, was used to dye cotton fabrics. After exposure to a dilute sodium hypochlorite solution, dyed cotton fabrics showed excellent anti‐bacterial properties against Staphylococcus aureus and Escherichia coli O157:H7, facilitating a ca. 6‐log reduction in bacteria within a short period of contact. Compared with the dichlorotriazine reactive dye, the reactive dye precursor demonstrated comparable dyeing properties including exhaustion and fixation values. No differences in rub fastness, wash fastness or bleach fastness were detected between fabrics dyed with, respectively, dichlorotriazine reactive dye and the reactive dye precursor to N‐halamine.     

Modification of silica gel,cellulose, and polyurethane with a sterically hindered N‐halamine moiety to produce antimicrobial activity

The sterically hindered amine monomer 4‐[3‐triethoxysilylpropoxyl]‐2,2,6,6‐tetramethylpiperidine has been synthesized and covalently bonded to the surfaces of silica gel particles and cellulose (cotton) and copolymerized in a polyurethane coating formulation. Upon exposure to dilute sodium hypochlorite (household bleach), a very stable N‐Cl bond is formed in situ at the hindered amine nitrogen site. This source of oxidative chlorine provides an antimicrobial function to the silica gel, cotton, and polyurethane. Stability, regenerability, and biocidal efficacy data are presented. The new N‐halamine materials were remarkably effective against Staphylococcus aureus and Escherichia coli O157 : H7 in brief periods of contact. The materials should find application in water treatment and medical applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Macroscopic N‐halamine biocidal polymeric beads

The particle size of N‐halamine biocidal polymers was methodically modified forming beads of different sizes by blending water‐insoluble N‐halamine polyurethane with sodium alginate as the matrix and loading heterocyclic rings onto modified silica gels. The biological activity of the prepared beads and halogenated modified silica derivatives was evaluated against examples of Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) bacteria. The recycling possibilities and the optimum preparation conditions of the blended beads were investigated; blending prehalogenated polyurethane (5%, w/v) with sodium alginate (3%, w/v) followed by crosslinking with CaCl₂ (10%, w/v) at 40°C are the optimum preparation conditions for the alginate beads. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Novel regenerable N‐halamine polymeric biocides. I. Synthesis,characterization, and antibacterial activity of hydantoin‐containing polymers

Two novel cyclic‐amine monomers, i.e., 3‐allyl‐5,5‐dimethylhydantoin (ADMH) and 7,8‐benzo‐3 allyl‐1,3‐diazasprio[4.5]decane‐2,4‐dione (BADDD) were synthesized with good yields by reacting allyl bromide with 5,5‐dimethylhydantoin (DMH) and 7,8‐benzo‐1,3‐diazasprio[4.5]decane‐2,4‐dione (BDDD), respectively. The synthesized monomers were characterized by FTIR and ¹H‐NMR spectra, and copolymerized with acrylonitrile (AN), vinyl acetate (VAC), and methyl methacrylate (MMA) in a small monomer ratio of ADMH and BDDD, respectively. The copolymers were characterized by FTIR, ¹H‐NMR, and DSC studies. The N‐halamine derivatives of the corresponding copolymers were found to exhibit high antibacterial activities against Escherichia coli, and the antibacterial properties were durable and regenerable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2460–2467, 2001     

Cellulose nanofibers prepared by the N‐methylmorpholine‐N‐oxide method

The process of electrospinning is very suitable for obtaining fibers with a diameter on a nanometer scale. Such fibers can be spun from almost all kinds of known polymers, copolymers, and polymer blends. In this work, we present cellulose nanofibers obtained by the electrospinning process from spinning dopes containing cellulose dissolved in an N‐methylmorpholine‐N‐oxide/water system. Under different electrospinning process conditions, cellulose fibers, a nonwoven fiber network, and a cellulose membrane were obtained. The fibers were examined with scanning electron microscopy. The diameters of the fibers were in the submicrometer range. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1855–1859, 2005     

Development of antimicrobial stainless steel via surface modification with N‐halamines: Characterization of surface chemistry and N‐halamine chlorination

N‐halamine modification of materials enables the development of antimicrobial materials whose activity can be regenerated after exposure to halogenated sanitizers. Surface and bulk modification of polymers by N‐halamines has shown great success, however, modification of inorganic substrates (e.g., stainless steel) remains an area of research need. Herein, we report the covalent surface modification of stainless steel to possess rechargeably antimicrobial N‐halamine moieties. Multilayers of branched polyethyleneimine and poly(acrylic acid) were immobilized onto the surface of stainless steel and the number of N‐halamines available to complex chlorine was quantified. Samples were characterized through contact angle, Fourier transform infrared spectroscopy, ellipsometry, dye assay for amine quantification, and X‐ray photoelectron spectroscopy. Increasing the number of multilayers from one to six increased the number of N‐halamines available to complex chlorine from 0.30 ± 0.5 to 36.81 ± 5.0 nmol cm^?2. XPS and FTIR confirmed successful covalent layer‐by‐layer deposition of the N‐halamine multilayers. The reported layer‐by‐layer deposition technique resulted in a greater than seven‐fold increase of available N‐halamine compared to prior reports of N‐halamine surface modifications. The N‐halamine modified steel demonstrated antimicrobial activity (99.7% reduction) against the pathogen Listeria monocytogenes. Such surface modified stainless steel with increased N‐halamine functionality, and therefore potential for rechargeable antimicrobial activity, supports efforts to reduce cross‐contamination by pathogenic organisms in the food and biomedical industries. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Co‐electrospun nanofibers of PVA‐SbQ and Zein for wound healing

In this study, electrospun biocompatible nanofibers with random orientation were prepared by physically blending poly(vinyl alcohol)‐stilbazol quaternized (PVA‐SbQ) with zein in acetic acid solution for wound healing. PVA‐SbQ was used as the foundation polymer as well as crosslinking agent, blended with zein to achieve desirable properties such as improved tensile strength, surface wettability, and in vitro degradable properties. Moreover, vaccarin drug was incorporated in situ into electrospun nanofibrous membranes for cell viability and cell attachment. The addition of vaccarin showed great effects on the morphology of nanofiber and enhanced cell viability and proliferation in comparison with composite nanofibers without drug. The presence of PVA‐SbQ, zein, and vaccarin drug in the nanofibrous membranes exhibited good compatibility, hydrophilicity, and biocompatibility and created a moist environment to have potential application for wound healing. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42565.     

Preparation,characterization, and antibacterial activities of quaternarized N‐halamine‐grafted cellulose fibers

A viable method for coating of cellulose fiber with quaternarized N‐halamine is reported in this article. The use of quaternary ammonium salt group in combination with N‐halamine group can reinforce the antibacterial activity. The chemical structure of as‐synthesized N‐halamine precursor 4‐(Bromo‐acetic acid methylester)‐4‐ethyl‐2‐ oxazolidinone (BEO) was characterized by ¹H‐NMR. The cellulose fibers were characterized by Fourier transform infrared spectra and X‐ray photoelectron spectra. The spectra data confirmed that the quaternarized N‐halamine‐grafted cellulose fibers were successfully obtained. The antibacterial properties of functional fibers were challenged with both Gram positive and Gram negative bacteria. The antibacterial tests and showed that the as‐prepared antibacterial cellulose fibers exhibited powerful and rapid bactericidal performance against both Gram negative E. coli and Gram positive S. aureus. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42702.     

Modification of cellulose/chitin mix fibers with N‐isopropylacrylamide and poly(N‐isopropylacrylamide) under cold plasma conditions

A two‐step grafting procedure was applied to cellulose/chitin (CC) mix fibers, namely: activation under the action of cold plasma discharges, followed by reaction with N‐isopropylacrylamide (NIPAAm) and poly(N‐isopropylacrylamide) (PNIPAAm) to obtain fibers with responsiveness to external stimuli. The graft samples were characterized using attenuated total reflection Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction, scanning electron microscopy coupled with energy‐dispersive X‐ray microanalysis and antimicrobial testing. All obtained results confirm the morphological and structural changes after plasma treatment which determine the modification of cellulose fiber properties. It was estimated from XPS data that the degrees of modification/grafting were about 23% for CC/NIPAAm and 13% for CC/PNIPAAm. Such treatment could be transferred to practical technologies, particularly in textile applications and special applications in the medical field. Copyright © 2012 Society of Chemical Industry