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1.
Chitosan coating of polyethylene (PE) was proposed as a new procedure to improve its biocompatibility and surface properties. The functionalization of the PE film surface by covalent bonding of chitosan coating and its effect on the surface mechanical properties, as surface elasticity, stiffness, and adhesion (that are important in different biological processes) were investigated by nano‐indentation, scratch, and atomic force microscopy. It has been established that chitosan grafting onto corona functionalized PE surface using various coupling agents significantly improves the surface hardness and elastic modulus although they decrease in depth of the layer. Compared to the neat PE substrate, the chitosan coated samples show significant improved friction properties and tear resistance. The surface roughness features correlate with the micro‐mechanical parameters. Therefore, the covalent immobilization of the chitosan onto PE leads to a stable coating with better mechanical performance being recommended as a promising material for medical applications and food packaging. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42344.  相似文献   

2.
Macroporous crosslinked acrylonitrile‐divinylbenzene copolymer beads were synthesized by suspension polymerization technique. The beads were chemically modified to have amidoxime functional group, which was used as a solid support for anchoring copper microparticles. The copper ions loaded on the copolymer beads were reduced using strong reducing agent to have copper microparticles on the amidoxime copolymer beads. The size of copper particles formed depends upon the amount of copper ions loaded on the beads. The formation of copper microparticles on the copolymer was confirmed by instrumental analysis. The copper containing amidoxime copolymer beads were investigated for the biocidal activity. The size and the distribution of copper particles on the amidoxime copolymer beads influenced their biocidal activity. The biocidal activity was tested against two Gram‐positive bacteria, Bacillus subtilis and Staphylococcus aureus, and against two Gram‐negative bacteria, Pseudomonas aeruginosa and Escherichia coli. The beads containing copper particles showed better biocidal activity against the Gram‐negative bacteria when compared with the Gram‐positive organisms. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

3.
Endoscopic palliation for the obstructive jaundice caused by biliary or pancreatic malignant tumors is a commonly used medical treatment. However, plastic biliary stents are occluded by sludge deposition caused by bacterial adhesion in 3–5 months. Chitosan, which has both good biocompatibility and antimicrobial capability, was used to modify the inner surface of polyethylene (PE) tubing in this study. Chitosan was deposited onto the inner surface of oxidized PE tubing with the methanol precipitation technique. Attenuated total reflection/Fourier transform infrared and electron spectroscopy for chemical analysis indicated that the chitosan coating was feasible. Contact‐angle measurements revealed that the surface hydrophilicity of the PE tubing increased with the chitosan coating. Morphological analysis with scanning electron microscopy showed that the PE surface became rougher and exhibited micropores after the chitosan coating. The adhesion of living Escherichia coli to chitosan‐coated PE stents, characterized by the spreading plate method and scanning electron microscopy analysis, was more significant than that to unmodified stents after a 24‐h phosphate‐buffered saline or bile perfusion test. This finding may be attributed to the rougher and slightly positively charged surface of chitosan‐coated PE tubing and to the ? CH3 hydrophobic functional groups in the chitosan structure. Because of its good biocompatibility, chitosan coated on the surface of PE can still be used for biliary stent applications with further chemical modification, such as sulfonation and quaternization, to increase its antimicrobial ability. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 893–902, 2005  相似文献   

4.
Novel nanocomposite films of chitosan/phosphoramide/Ag NPs were prepared containing 1–5% of silver nanoparticles. The Ag NPs were synthesized according to the citrate reduction method. The XRD and SEM analysis of Ag NPs, chitosan (CS), phosphoramide (Ph), CS/Ph, CS/Ag NPs films and the nanocomposite films 1–5 containing CS/Ph/1–5% Ag NPs were investigated. The in vitro antibacterial activities were evaluated against four bacteria including two Gram‐positive Staphylococcus aureus (S. aureus), Bacillus cereus (B. cereus) and two Gram‐negative Escherchia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) bacteria. Results revealed greater antibacterial effects of the films against Gram‐positive bacteria. Also, nanocomposite films containing higher percent of Ag NPs showed more antibacterial activities. POLYM. COMPOS. 36:454–466, 2015. © 2014 Society of Plastics Engineers  相似文献   

5.
The 2‐N‐thiosemicarbazide‐6‐O‐hydroxypropyl chitosan (ATU‐HPCS) was prepared by chitosan grafted hydroxypropyl and thiosemicarbazide through the method of “amino protection‐graft‐deprotection,” while the ATU‐HPCS gel membranes were obtained from gelatin and polyvinyl pyrrolidone as additives, and the ATU‐HPCS membranes with iodine (ATU‐HPCS‐I2‐M) were prepared by adding the ethanol solution of iodine in the ATU‐HPCS gel membranes. The ATU‐HPCS‐I2‐M were characterized to evaluate their potential applications as antibacterial materials. The iodine releasing rule of ATU‐HPCS‐I2‐M showed a sustained‐release effect of iodine, the maximum emission was approximately 0.80%. The inhibition zone diameters of ATU‐HPCS‐I2‐M against Staphylococcus aureus (as Gram‐positive bacteria) and Escherichia coli (as Gram‐negative bacteria) were both greater than 15 mm, it demonstrated significant antibacterial activity compared with the ATU‐HPCS gel membranes. The double effects of the biocompatibility of chitosan and the sustained‐release of iodine provided an ideal healing environment for wound surface. These properties have made ATU‐HPCS‐I2‐M highly potential as a novel natural macromolecule antimicrobial material preventing the bacteria from burns, surgery wounds, etc. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40535.  相似文献   

6.
N‐(hydroxymethyl) acrylamide (NMA) was immobilized on cotton surfaces through etherification, and then methacrylamide (MA) was grafted onto the treated surface. The coatings were characterized by ATR‐IR spectroscopy and were rendered biocidal upon exposure to dilute household bleach. The treated fabrics were challenged with Gram‐negative and Gram‐positive bacteria; both NMA and NMA/MA‐treated fabrics inactivated about 8 logs of Escherichia coli O157:H7 and Staphylococcus aureus within only 5 min of contact time. The coatings were also quite stable toward ultraviolet (UVA) light exposure and repeated laundering. Moreover, a substantial improvement in wrinkle recovery angle was obtained for the NMA/MA‐treated fabrics. The new acyclic acrylamide N‐halamine coating should be less expensive to produce and use than previous cyclic N‐halamine coatings developed in these laboratories. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

7.
N‐acyl chitosans (such as N‐acetylated, N‐maleyl, and N‐succinyl chitosan), which were synthesized in glycine chloride ([Gly]Cl)/water homogeneous system, were of better moisture‐absorption and moisture‐retention abilities than those from the traditional methods, even better than hyaluronic acid. Moreover, the new method overcame many shortcomings, such as long reaction time, gel formed during the process of reaction, and complex workup procedure. In addition, the new [Gly]Cl solvent system was of the low volatility and no corrosion compared with organic solvent, especially, could be repeatedly used. Therefore, an environmental friendly approach for the synthesis of N‐acyl chitosan was provided. At the same time, the N‐acetylated chitosan fibers by wet‐spinning using N‐acetylated chitosan‐[Gly]Cl as spinning dope solution were firstly reported, and the fibers had smooth surface as well as round and compact structure. More to the point, the N‐acetylated chitosan fibers directly prepared in this study were of excellent mechanical properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

8.
Modification of woolen fabrics was done by the grafting of low‐molecular‐weight deacetylated chitosan in the presence of citric acid as a crosslinking agent with the pad–dry cure method at different conditions (times and temperatures). The add‐on of chitosan and the optimum conditions were determined. The improved properties of modified wool by chitosan were evaluated with the urea bisulfite solubility test, crease recovery angle, yellowness index, and scanning electron microscopy. The dyeing properties of modified wool fabrics were studied with acid and reactive dyes. The biocidal activities of the modified and unmodified wool samples were evaluated and compared against some species of microorganisms, including Escherichia coli (Gram negative), Staphylococcus aureus (Gram positive), Candida albicans, and Aspergillus flavus. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

9.
The antimicrobial polymer/polymer macrocomplexes were synthesized by radical alternating copolymerization of N‐vinyl‐2‐pyrrolidone with maleic anhydride [poly(VP‐alt‐MA)] with 2,2′‐azobis‐isobutyronitrile as an initiator at 65°C in dioxane solutions under nitrogen atmosphere, and interaction of prepared copolymer with poly(ethylene imine) (PEI) in aqueous solutions. The susceptibility of some Gram‐negative (Salmonella enteritidis and Escherichia coli) and Gram‐positive (Staphylococcus aureus and Listeria monocytogenes) bacteria to the alternating copolymer and its PEI macrocomplexes with different compositions in microbiological medium was studied using pour‐plate technique. All the studied polymers, containing biologically active moieties in the form of ionized cyclic amide, and macrobranched aliphatic amine groups and acid/amine complexed fragments, were more effective against L. monocytogenes than those for Gram‐positive S. aureus bacterium. This fact was explained by different surface layer structural architectures of biomacromolecules of tested bacteria. The resulting polymeric antimicrobial materials are expected to be used in various areas of medicine and food industry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5841–5847, 2006  相似文献   

10.
In this work, poly(ethylene glcycol)‐grafted chitosan (PEG‐g‐CS) was synthesized by conjugating PEG to the chitosan (CS) backbone. Such PEGylated CS copolymer was further characterized by FTIR and 1H NMR, and the results demonstrated the successful synthesis. After PEGylation, the water solubility of CS was significantly improved due to the hydrophilicity of the PEG polymer. Therefore, this PEGylated CS was prepared as water borne coating for leather surface. The morphology and hydrophilicity of this coating on leather was studied by SEM and water contact angle measurement. Furthermore, the antimicrobial activity of PEGylated CS coating was investigated by measuring its minimum inhibitory concentration and the inhibition zone of coated leather against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus, respectively. Compared to CS coating, such PEG‐g‐CS coating exhibited better antimicrobial property, which indicated the synergetic effect of the antimicrobial property of CS and the antiadhesive property of PEG. Thus, this PEGylated CS copolymer can be used as efficiently antimicrobial coating for leather product. © 2016 The Authors Journal of Applied Polymer Science Published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43465.  相似文献   

11.
Four cationic surfactants of quaternary hexammonium silane chloride based on hexamethylenetetramine and alkyl chloride were synthesized. The chemical structures of the prepared cationic surfactants were elucidated using Fourier transform infrared (FT‐IR) spectroscopy and mass spectrometry analysis. The surface and thermodynamic properties of the prepared surfactants were also studied. The performance of these cationic surfactants as microfouling agents against two strains of Gram‐negative bacteria, namely, Pseudomonas aeruginosa and Escherichia coli, and two strains of Gram‐positive bacteria, namely, Staphylococcus aureus and Bacillus subtilis, were evaluated as antimicrobial agents. The results showed that the maximum antimicrobial activity was detected for N‐hexamethylenetetramine‐N‐ethyl silane ammonium trichloride (Ah). The maximum and minimum antimicrobial activities were 73 and 60 % against S. aureus and E. coli, respectively, at a concentration of 5 mg/l, pH 7, and 37 °C.  相似文献   

12.
N,O‐(2‐carboxyethyl)chitosan (N,O‐2‐CEC) was prepared from chitosan with 3‐chloropropionic acid as modifying agent and NaOH as binding‐acid agent. 2‐Hydroxypropyl dimethylbenzylammonium N,O‐(2‐carboxyethyl) chitosan chloride (HPDMBA‐CEC) was obtained by the reaction of N,O‐2‐CEC with glycidyl dimethyl benzyl ammonium chloride (GDMBA) using NaOH as catalyst. The structures of chitosan derivatives were characterized by FTIR, 1H NMR, and gel permeation chromatography. The antimicrobial activity of HPDMBA‐CEC was evaluated against a Gram‐negative bacterium Escherichia coli (E.coli) and a Gram‐positive bacterium Staphylococcus aureus (S. aureus). Compared with CTS, N,O‐2‐CEC, and HPDMBA‐CTS, HPDMBA‐CEC had much stronger antimicrobial activity, and this activity increased with increasing substitution degree of quaternary ammonium group (DQ). When the substitution degree of carboxyethylation (DS of CE) was 0.72 and DQ was 0.60, the minimum inhibitory concentrations (MICs) of HPDMBA‐CEC were 3.1 and 6.3 μg/mL against S. aureus and E. coli, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009  相似文献   

13.
A complex of chitosan (CS‐40) and nisin (CS‐40/nisin) was prepared and characterized with Fourier transform infrared spectroscopy and thermal analysis (thermogravimetry, differential thermogravimetry, and differential scanning calorimetry). The results show that the complex formed mainly by electrostatic interaction between the protonated amino group in CS‐40 backbone with the carboxylate ion of nisin. Minimum inhibitory concentrations (MICs) were evaluated against Gram‐positive bacteria (Staphylococcus aureus, Bacillus subtilis, and Bacillus stearothermophilus), Gram‐negative bacteria (Escherichia coli, Salmonella enteritidis, and Proteus vulgaris), and fungi (Fusarium oxysporum). The results show that the CS‐40/nisin solution did inhibit or even more strongly inhibited the growth of all the tested microorganisms, whereas CS‐40 did not inhibit the growth of F. oxysporum and nisin did not inhibit the growth of Gram‐negative bacteria (E. coli, S. enteritidis, and P. vulgaris). The relative inhibition times of CS‐40/nisin solutions with different concentrations and ratios of CS‐40 and nisin were also investigated against the seven microorganisms. The results showed that CS‐40/nisin solutions with CS‐40/nisin concentration ratios of 0.05/0.005, 0.05/0.0025, 0.05/0.00125, and 0.025/0.0001% had higher antimicrobial activity against all tested bacteria and fungi. The relationship between complex formation and antimicrobial activity is discussed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

14.
The O‐fumaryl ester (OFTMCS) of N,N,N‐trimethyl chitosan (TMCS) has been synthesized as a water‐soluble chitosan (CS) derivative bearing dual‐functional groups, with the aim of discovering novel CS derivatives with good water solubility and enhanced the antibacterial activity compared with unmodified CS. OFTMCS was characterized by FT‐IR, 13C NMR, XPS, XRD and Zeta potential analyses. The XPS results indicated that the degree of substitution (DS) on the C2‐NH2 group of the CS was 0.78, and that the DS on its C6‐OH group was 0.31. The TGA results showed that the thermal stability of OFTMCS was lower than that of unmodified CS. The antibacterial activities of OFTMCS were investigated by assessing the mortality rates of the representative Gram‐positive and Gram‐negative bacteria Staphylococcus aureus and Escherichia coli, respectively. The results indicated that OFTMCS exhibited superior antibacterial activity to CS at a lower dosage. The synthesis of CS derivatives bearing dual‐functional groups could therefore be used as a promising strategy to enhance the antibacterial activity of CS. The antimicrobial mechanism of action of OFTMCS was discussed. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42663.  相似文献   

15.
The impact of chitosan on the natural weathering behavior of two blends obtained by mixing either polyethylene (PE) with chitosan or PE, chitosan and polyethylene‐graft‐maleic anhydride (PEgMA) as a compatibilizer is analyzed. In order to follow the weathering behavior of both the uncompatibilized and compatibilized systems, the blend films are exposed to outdoor conditions for 6 months. The weathering behavior of the films is monitored by mechanical tests, spectroscopic Fourier transform infrared, and morphological analyses at different weathering periods of time. The presence of chitosan in the blends accelerates significantly the degradation of the films. Apparently, PEgMA also accelerates the photo‐oxidation rate of the films. This behavior appears to be related to the photo‐oxidative instability of maleic anhydride, and also to the better dispersion of chitosan in the PE matrix, which is due to the interactions in the PE/chitosan interface caused by the addition of the compatibilizer. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41045.  相似文献   

16.
As an attempt to combine the dyeing and functional finishing steps into one process, two novel anti‐bacterial monoazo acid dyes based on N‐ester‐1,8‐naphthalimide were synthesised. To do this, 4‐amino‐N‐ethyl glycinate‐1,8‐naphthalimide was prepared, diazotised and then coupled to thiosalicylic acid or salicylic acid to produce anti‐bacterial dyes. The synthesised dyes were purified and then fully characterised using Fourier Transform–infrared spectrometry, proton nuclear magnetic resonance spectroscopy and melting point analysis. Dispersion of the dyes was prepared in water and applied to nylon 6 fabrics. The novel dyes offered good build‐up properties on the substrate. The anti‐bacterial efficacy of the synthesised dyes was assessed, with the dyes showing activity against both Gram‐positive and Gram‐negative bacteria.  相似文献   

17.
With the widespread emergence of drug resistance, there is an urgent need to search for new antimicrobials, especially those against Gram‐negative bacteria. Along this line, the identification of viable targets is a critical first step. The protein translocase SecA is commonly believed to be an excellent target for the development of broad‐spectrum antimicrobials. In recent years, we developed three structural classes of SecA inhibitors that have proven to be very effective against Gram‐positive bacteria. However, we have not achieved the same level of success against Gram‐negative bacteria, despite the potent inhibition of SecA in enzyme assays by the same inhibitors. In this study, we use representative inhibitors as chemical probes to gain an understanding as to why these inhibitors were not effective against Gram‐negative bacteria. The results validate our initial postulation that the major difference in effectiveness against Gram‐positive and Gram‐negative bacteria is in the additional permeability barrier posed by the outer membrane of Gram‐negative bacteria. We also found that the expression of efflux pumps, which are responsible for multidrug resistance (MDR), have no effect on the effectiveness of these SecA inhibitors. Identification of an inhibitor‐resistant mutant and complementation tests of the plasmids containing secA in a secAts mutant showed that a single secAazi‐9 mutation increased the resistance, providing genetic evidence that SecA is indeed the target of these inhibitors in bacteria. Such results strongly suggest SecA as an excellent target for developing effective antimicrobials against Gram‐negative bacteria with the intrinsic ability to overcome MDR. A key future research direction should be the optimization of membrane permeability.  相似文献   

18.
In this work, PEGylated chitosan derivatives were prepared and used to modified poly(ethylene terephthalate) (PET) fabrics. PET fabrics surface were etched by oxygen plasma before different concentrations PEGylated chitosan derivatives solution treatment. The effects of oxygen plasma and PEGylated chitosan derivatives on the surface properties of PET fabrics are investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Surface wettability was monitored by water contact angle measurement and moisture regains. The results showed that the occurrence of oxygen‐containing functional groups (i.e., C?O, C? O, and ? OH) of the plasma‐treated PET and the surface coarseness increased from those of the untreated one. There was a layer film formed on the surface of PET fabrics after PEGylated chitosan modification. The combination treatment of oxygen plasma with PEGylated chitosans lightly lowered the breaking strength and elongation of PET fabric. That moisture regains increased and the contact angle decreased implied the hydrophilicity enhancement for the PET fabrics. In addition, dyeing property of PEGylated chitosan derivative modified PET was improved. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39693.  相似文献   

19.
Ultrahigh‐molecular‐weight polyethylene (UHMWPE)/polar polyethylene (PE) composites were blended in one nascent particle by in situ polymerization with a hybrid catalyst. Polystyrene‐coated SiO2 particles were used to support the hybrid catalyst. Fe(acac)3/2,6‐bis[1‐(2‐isopropylanilinoethyl)] was supported on SiO2 for the synthesis of UHMWPE, whereas [PhN?C(CH3)CH?C(Ph)O]VCl2 was immobilized on a polystyrene layer to prepare a copolymer of ethylene and 10‐undecen‐1‐ol (polar PE). Importantly, the core part of the supports (the polystyrene layer) exhibited pronounced transfer resistance to 10‐undecen‐1‐ol; this provided an opportunity to keep the inside iron active sites away from the poisoning of 10‐undecen‐1‐ol. Therefore, UHMWPE was simultaneously synthesized with polar PE by in situ polymerization. Interestingly, the morphological results show that UHMWPE and the polar PE were successfully blended in one nascent polymer. This improved the miscibility of the composites, where most of the chains were difficult to crystallize because of the strong interactions between the PE chains and polar chains. The blends showed an extremely low crystallinity, that is, 9.9%. Finally, the hydrophilic properties of the polymer composites were examined. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46652.  相似文献   

20.
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  相似文献   

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