In vitro and in vivo investigational studies of a nanocomposite‐hydrogel‐based dressing with a silver‐coated chitosan wafer for full‐thickness skin wounds

A nanocomposite reservoir‐type hydrogel dressing of poly vinyl alcohol (PVA) was fabricated by a freeze–thaw method and loaded with silver‐nanoparticle‐coated chitosan wafers (Ag–CHWs). The Ag–CHWs were synthesized by a sonication technique with silver nitrate (AgNO₃) and chitosan powder. Scanning electron microscopy images showed silver nanoparticles (AgNPs) with a size range of 10 ± 4 nm on the surface of the chitosan wafers, and the antibacterial efficacy (minimum inhibitory concentration) of the Ag–CHWs was measured against Pseudomonas aeruginosa (32 µg/mL), Staphylococcus aureus, (30 µg/mL) and Escherichia coli (32 µg/mL). The antimicrobial PVA hydrogel showed an improved tensile strength (～0.28 MPa) and gel content (～92%) in comparison with the blank hydrogels. Full‐thickness‐excision wound studies of the nanocomposite dressing on Wistar rats revealed enhanced wound contraction, improved inflammation response, re‐epithelization rate, neoangiogenesis, and granulation tissue formation in comparison to the control group. A flexible, biocompatible, nanocomposite reservoir dressing not only established the chitosan as a stabilizer but also proved the efficacious and safe utility of AgNPs toward chronic wound management. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43472.     

Carboxymethylcellulose (CMC) as a model compound of cellulose fibers and polyamideamine epichlorohydrin (PAE)–CMC interactions as a model of PAE–fibers interactions of PAE‐based wet strength papers

Carboxymethylcellulose (CMC) is a cellulose derivative obtained by the carboxymethylation of some hydroxyl groups in the cellulose macromolecules. In this article, we use CMC as a model compound of cellulose fibers to study polyamineamide epichlorohydrin (PAE)–fibers interactions during the preparation of PAE‐based wet strength papers. The main advantages of the use of CMC to replace cellulose fibers are its water‐soluble character and the homogeneous reaction medium during mixing with PAE resin. Based on ¹³C cross‐polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) and Fourier transformed infra‐red (FTIR) spectroscopy, we prove the formation of ester bonds in PAE–CMC films boosted by a thermal posttreatment at 105°C for 24 h. These ester bonds are derived from a thermally induced reaction between carboxyl groups in the CMC structure and azetidinium ions (AZR) in the PAE resin. PAE‐based handsheets were prepared from 100% Eucalyptus fibers. After preparation, some samples were thermally posttreated (TP) at 130°C for 10 min and stored under controlled conditions (25°C and 50% relative humidity or RH). For lowest PAE dosage, storage of the not thermally posttreated (NTP) PAE‐based handsheets does not allow them to reach the tensile strength values of TP PAE‐based handsheets (at 130°C for 10 min), but the difference in terms of breaking length remains low. For the highest PAE addition level, NTP and TP PAE‐based handsheets exhibit close values of the breaking length from 30 days of storage under controlled conditions (25°C and 50% RH). When a thermal posttreatment is applied, the wet strength development of PAE‐based papers is a combined effect of homo‐ and co‐cross‐linking mechanisms. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42144.     

A comparison of partially acetylated nanocellulose,nanocrystalline cellulose,and nanoclay as fillers for high‐performance polylactide nanocomposites

Partially acetylated cellulose nanofibers (CNF) were chemically extracted from sisal fibers and the performance of those CNF as nanofillers for polylactide (PLA) for food packaging applications was evaluated. Three PLA nanocomposites; PLA/CNF (cellulose nanofibers), PLA/CNC (nanocrystalline cellulose), and PLA/C30B (Cloisite^TM 30B, an organically modified montmorillonite clay) were prepared and their properties were evaluated. It was found that CNF reinforced composites showed a larger decrease on oxygen transmission rate (OTR) than the clay‐based composites; (PLA/CNF 1% nanocomposite showed a 63% of reduction at 23°C and 50% RH while PLA/C30B 1% showed a 26% decrease) and similar behavior on terms of water vapor barrier properties with 46 and 43%, respectively of decrease on water vapor transmission rate at 23°C and 50% RH (relative humidity). In terms of mechanical and thermomechanical properties, CNF‐based nanocomposites showed better performance than clay‐based composites without affecting significantly the optical transparency. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43257.     

Hyperbranched polycarboxylates and their nanocomposites with ZnO: Investigations on the humidity‐sensitive properties

Hyperbranched polycarboxylates (HBPC) with different alkali metal cations (Li⁺, Na⁺, and K⁺) were prepared and characterized by ¹H‐NMR and thermal gravimetric analysis. Thin film humidity sensors based on HBPC and its composite with ZnO nanorods were fabricated. The morphologies of films of HBPC and the nanocomposite were investigated by atomic force microscopy, which revealed uniform distribution of ZnO nanorods in HBPC. The humidity‐sensitive characteristics of HBPC and the nanocomposite were investigated at room temperature. It was found that the type of cations significantly affected the humidity‐sensing behaviors of HBPC. In addition, the nanocomposite exhibited better humidity‐sensitive properties than HBPC alone. Its impedance decreased for about three orders of magnitude over the range 19–97% RH, showing high sensitivity. Moreover, the nanocomposite exhibited fast response (～ 9 and 10 s for response and recovery time between 97% RH and 33% RH, respectively) and small hysteresis (～ 1.4% RH). The improved humidity‐sensing behaviors of the nanocomposite over HPBC alone is explained by taking into account the hyperbranched structure of the polymer and the special interactions of the polymer and ZnO with water molecules. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Integrated PLGA–Ag nanocomposite systems to control the degradation rate and antibacterial properties

Biodegradable polymer based nanocomposite materials have attracted much attention since they can be used for biomedical and pharmaceutical applications. In order to have highly integrated PLGA nanocomposite materials, silver colloidal nanoparticles were prepared in chloroform starting from silver nitrate and using polyvinylpyrrolidone as reduction and capping agent. TEM and AFM imaging give information on the size distribution of the silver nucleus (7.0 nm) and the capping shell (8.2–10.7 nm). PLGA–Ag nanocomposites were prepared upon addition of 1 or 3% wt of silver nanoparticles to the PLGA/chloroform suspension. The effect of silver loading on polymer degradation was studied following the mass loss and the morphology of nanocomposite films at different degradation stages. The concentrations of Ag⁺, which is released during nanocomposite degradation, were monitored and analyzed through the diffusion model, to have insight on the degradation kinetics. The release rate, and likely the degradation rate, was reduced at higher silver loading. Bacterial growth tests indicated that the cell growth is inhibited in the presence of PLGA–Ag nanocomposites and the efficiency is correlated to Ag⁺ release. Thus, controlling the nanoparticle loading, a tunable degradation and antibacterial action can be designed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1185‐1193, 2013     

Room temperature preparation,electrical conductivity,and thermal behavior evaluation on silver nanoparticle embedded polyaniline tungstophosphate nanocomposite

An advanced nanocomposite, polyaniline tungstophosphate (PANI‐WP) cation exchanger, was synthesized by simple solution method and treated with silver nitrate resulting silver embedded PANI‐WP (PANI‐WP/Ag). Spectroscopic characterization of PANI‐WP/Ag was carried out by scanning electron microscopy, fourier transform infrared spectroscopy, UV‐Visible spectroscopy, and X‐ray diffraction. Electrical conductivity measurements and thermal effect on conductivity of PANI‐WP/Ag was studied after acid treatment. The dc electrical conductivity was found 3.06 × 10⁻³ S cm⁻¹ for HCl doped, measured by 4‐in line‐probe dc electrical conductivity measuring technique. Thermal conductivity is stable with all temperatures in isothermal studies showing excellent stability of PANI‐WP/Ag material. Hybrid showed better linear Arrhenius electric conducting response for semiconductors, stable upto 120°C. It was observed that conductivity is at the border of metallic and semiconductor region. POLYM. COMPOS., 37:2460–2466, 2016. © 2015 Society of Plastics Engineers     

Fabrication of polysulfone nanocomposite membranes with silver‐doped carbon nanotubes and their antifouling performance

In this study, polysulfone (PSf)/silver‐doped carbon nanotube (Ag‐CNT) nanocomposite membranes were prepared by a phase‐inversion technique; they were characterized and evaluated for fouling‐resistant applications with bovine serum albumin (BSA) solutions. Carbon nanotubes were doped with silver nanoparticles via a wet‐impregnation technique. The prepared Ag‐CNT nanotubes were characterized with scanning electron microscopy (SEM)/energy‐dispersive X‐ray spectroscopy, X‐ray diffraction, Raman spectroscopy, and thermogravimetric analysis. The fabricated flat‐sheet PSf/Ag‐CNT nanocomposite membranes with different Ag‐CNT loadings were examined for their surface morphology, roughness, hydrophilicity, and mechanical strength with SEM, atomic force microscopy, contact angle measurement, and tensile testing, respectively. The prepared composite membranes displayed a greater rejection of BSA solution (≥90%) and water flux stability during membrane compaction with a 10% reduction in water flux values (up to 0.4% Ag‐CNTs) than the pristine PSf membrane. The PSf nanocomposite membrane with a 0.2% Ag‐CNT loading possessed the highest flux recovery of about 80% and the lowest total membrane resistance of 56% with a reduced irreversible fouling resistance of 21%. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44688.     

Dielectric and AC conductivity studies of novel porous armalcolite nanocomposite‐based humidity sensor

Armalcolite, a current motivated rare earth ceramic usually available in the moon, had been used for the first time, as dielectric‐type humidity sensors. The armalcolite nanocomposite was prepared using multistep solid‐state sintering under high pressure and a high‐sensitive dielectric sensor was developed for humidity controlling applications. Different concerning phases developed by the proper sintering were analyzed precisely by X‐ray diffraction (XRD) as well as scanning electron microscopy (SEM). At 100 Hz frequency, the obtained dielectric constant was 24 times greater at 95% relative humidity (RH) as compared to 33% RH. The armalcolite‐based sensor showed lower hysteresis (<3.5%), good stability, and faster response (~18 seconds) and recovery (~35 seconds) times compared to conventional humidity sensors. The sensing mechanism of the nanocomposite was categorically determined by the analyzed characteristics parameters such as dielectric constants, normalized loss tangent, and alternating current conductivity properties. This study also confirmed that the whole conduction mechanism was accomplished by electrons or ions and dipoles in the entire RH range. Therefore, the present armalcolite‐based porous nanocomposite would be a potential sensing material for novel humidity sensors.     

Silver/poly(N‐vinyl‐2‐pyrrolidone) hydrogel nanocomposites obtained by electrochemical synthesis of silver nanoparticles inside the polymer hydrogel aimed for biomedical applications

Silver nanoparticles were produced inside a poly(N‐vinyl‐2‐pyrrolidone) hydrogel (PVP) by an innovative method based on the electrochemical reduction of Ag⁺ ions within the swollen PVP hydrogel. UV‐visible spectroscopy showed the highest value of the absorbance intensity and the lowest values of the wavelength of the absorbance maximum and the full width at the half‐maximum absorbance for the Ag/PVP nanocomposite obtained at 200 V during 4 min. Cyclic voltammetry results suggested an adequate entrapment of the silver nanoparticles. The mechanical properties under bioreactor conditions of the Ag/PVP nanocomposite suggested the possibility of wound dressing application. Silver release from Ag/PVP nanocomposites was confirmed under static conditions as well as by their antimicrobial activity against Staphylococcus aureus. POLYM. COMPOS., 35:217–226, 2014. © 2013 Society of Plastics Engineers     

Microwave-assisted green synthesis of Ag/reduced graphene oxide nanocomposite as a surface-enhanced Raman scattering substrate with high uniformity

A nanocomposite of silver nanoparticles/reduced graphene oxide (Ag/rGO) has been fabricated as a surface-enhanced Raman scattering (SERS) substrate owing to the large surface area and two-dimensional nanosheet structure of rGO. A facile and rapid microwave-assisted green route has been used for the formation of Ag nanoparticles and the reduction of graphene oxide simultaneously with L-arginine as the reducing agent. By increasing the cycle number of microwave irradiation from 1 and 4 to 8, the mean diameters of Ag nanoparticles deposited on the surface of rGO increased from 10.3 ± 4.6 and 21.4 ± 10.5 to 41.1 ± 12.6 nm. The SERS performance of Ag/rGO nanocomposite was examined using the common Raman reporter molecule 4-aminothiophenol (4-ATP). It was found that the Raman intensity of 4-ATP could be significantly enhanced by increasing the size and content of silver nanoparticles deposited on rGO. Although the Raman intensities of D-band and G-band of rGO were also enhanced simultaneously by the deposited Ag nanoparticles which limited the further improvement of SERS detection sensitivity, the detectable concentration of 4-ATP with Ag/rGO nanocomposite as the SERS substrate still could be lowered to be 10⁻¹⁰ M and the enhancement factor could be increased to 1.27 × 10¹⁰. Furthermore, it was also achievable to lower the relative standard deviation (RSD) values of the Raman intensities to below 5%. This revealed that the Ag/rGO nanocomposite obtained in this work could be used as a SERS substrate with high sensitivity and homogeneity.     

Combination of polymeric substrates and metal–polymer nanocomposites for optical humidity sensors

This paper reports a combination of self-supported, 80-μm-thick polymeric substrates of poly(dimethyl siloxane), poly(methyl methacrylate), poly(vinyl alcohol) (PVA), and poly(N-vinylpyridine) (PVP) and nanocomposites, silver nanoparticle (nAg)/0.1% PVP (S1) and nAg/0.1% PVA (S2), for use in optical-transmission-type humidity sensors. Composites are synthesized by a chemical reduction method at optimum conditions, giving particle sizes of 5–10 nm and 10–20 nm, respectively, for nAg/0.1% PVP and nAg/0.1% PVA. Composite formation is confirmed using Fourier transform infrared spectroscopy (FTIR). The role of polymers in obtaining a smaller Ag particle size is studied using ultraviolet–visible spectroscopy and transmission electron microscopy. The nanocomposite is coated onto substrates either on a single side or on both sides by dip coating. The humidity response of nAg/0.1% PVP-0.1% PVP- nAg/0.1% PVP (S1-PVP-S1) sensors, measured using the direct optical transmission method, exhibits an enhancement in sensitivity [0.88 ± 0.04 (/% RH)] for the humidity range 6–94% RH and response (6 s) and recovery (8 s) times compared to nAg/0.1% PVP-PVP S1-PVP sensors and a linear response (R² ≥ 0.99). An attempt is made to explain the sensing process with the help of FTIR spectra in dry and humid environments. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47035.     

A convenient approach to synthesize stable silver nanoparticles and silver/polystyrene nanocomposite particles

In this study, silver nanoparticles were prepared by the reduction of silver nitrate in SDS+ isopentanol/styrene/H₂O reverse microemulsion system using sodium citrate as reducing agent. The Ag/PS nanocomposite particles were prepared by in situ emulsion polymerization of the styrene system containing silver nanoparticles that did not separate from the reaction solution. The polymerization dynamic characteristic was studied, at the same time, silver nanparticles and the encapsulation of composite particles were characterized by Fourier‐transform‐infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X‐ray diffraction (XRD) measurement, UV–vis diffuse reflectance spectroscopy, and X‐ray photoelectron spectroscopy (XPS). The results of TEM and UV–vis absorption spectra showed that well‐dispersed silver nanoparticles have a narrow size distribution. XRD showed that Ag and Ag/PS nanocomposite particles were less than 10 and 20 nm in size, which is similar to those observed by TEM. The results of XPS spectra revealed that the microemulsion system can stabilize the silver nanoparticles from aggregation and provided supporting evidence for the polystyrene encapsulated silver nanoparticle structure. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.     

Synthesis and characterization of dendritic polypyrrole silver nanocomposite and its application as a new urea biosensor

Polypyrrole and its silver nanocomposite were electrochemically synthesized from aqueous solutions containing pyrrole, potassium chloride (KCl) (system A); pyrrole, KCl, and an anionic surfactant sodium dodecyl sulphate (NaDS) (system B); and pyrrole, silver nitrate, NaDS (system C). Compact and dendritic patterns were observed depending on experimental conditions. The aggregates were characterized by powder X‐ray diffraction, energy‐dispersive X‐ray spectroscopy, scanning electron microscopy, high resolution transmission electron microscopic (HRTEM), and thermal studies (TG/DTG). HRTEM studies indicate that the particle size of PPy‐Ag nanocomposite is ～30 nm. TG studies revealed that systems B and C, have different thermal behavior. Potassium ion selective electrodes were constructed using systems A, B, and C. The electrode prepared with PPy‐Ag nanocomposite showed nernstian behavior with maximum slope of 57 mV. ion‐selective electrode was also constructed for this system based on nonactin‐impregnated PVC matrix membrane. Urease enzyme was immobilized at the surface of as made ion‐selective electrode to develop urea biosensor showing good detection limit. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45705.     

Removal behavior and mechanism of silver from low concentration wastewater using cellulose aerogel modified by thiosemicarbazide

Due to the low concentration of silver in water, most of the cellulose adsorbents exhibited low removal efficiency, which greatly limited their practical applications. Herein, a cellulose aerogel modified by thiosemicarbamide (CAT) was fabricated for reducing and adsorbing silver ions from low concentration wastewater. The characterization results concluded that CAT owned a three-dimensional spongy structure with many circular microspheres and a better specific surface area (19.37 m² g⁻¹), as well as the functional groups of ─C═N⁺─H and ─(C═S)─N. The static batch adsorption experiments demonstrated that CAT could reached the maximum removal percentage of 94.94% and adsorption capacity of 42.12 mg g⁻¹ under the initial concentration of Ag(I) was 15 mg L⁻¹ and the pH value was 7. Meanwhile, the adsorption of Ag(I) on CAT was second-order reaction, and the Langmuir model could better fit the adsorption process. In addition, CAT exhibited wide pH values (1–9) adaptability and excellent adsorption performance for silver through electrostatic interaction, chelation, and reduction. This study probably provides a new method as well as important experimental data and theoretical reference for the removal of silver ions and other metals.     

Preparation,characterization, and antibacterial properties of silver nanoparticles embedded into cellulose aerogels

In this article, highly loaded silver (Ag) nanoparticles with mean diameter of about 7.83 nm were synthesized by reducing Ag ions by NaBH₄ with strong reducibility, and homogeneously embedded into cellulose aerogels without obvious reunion. The as‐prepared nano‐Ag/cellulose (NAC) aerogels maintained nanoporous and multiscale morphology similar to the pure cellulose aerogels, and showed strong antibacterial activities for both Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive). Meanwhile, after the incorporation of Ag nanoparticles, NAC aerogels also displayed more superior thermal stability. Thus, the novel NAC aerogels might be expected to be used as various biomedical applications, especially green heat‐resistant high‐performance antibacterial materials. POLYM. COMPOS. 37:1137–1142, 2016. © 2014 Society of Plastics Engineers     

Preparation of antibacterial temperature‐sensitive silver‐nanocomposite hydrogels from N‐isopropylacrylamide with green tea

This article reports the temperature‐sensitive, green tea (GT)‐based silver‐nanocomposite hydrogels for bacterial growth inactivation. The temperature‐sensitive hydrogels were prepared via free‐radical polymerization using temperature‐sensitive N‐isopropylacrylamide (NIPAM) monomer with GT as the hydrogel matrix. The nanocomposite hydrogels were encapsulated with silver ions via swelling method, which was later reduced to silver nanoparticles using Azadirachta indica leaf extract. The temperature‐sensitive silver nanocomposite hydrogels were analyzed by using Fourier transforms infrared, UV–visible spectroscopy, differential scanning calorimetry–thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The prepared hydrogels exhibited higher phase volume transition temperature than the NIPAM. The inhibition zone study of the inactivation of bacteria on the developed hydrogels was carried out against Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus), which revealed that the prepared hydrogels are helpful for the inactivation of these bacteria due to the high stabilization of antibacterial properties of the silver nanoparticles. The developed hydrogels are promising for biomedical applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45739.     

A Novel Highly Sensitive Humidity Sensor Based on ZnO/SBA‐15 Hybrid Nanocomposite

This work deals with the study of hydrothermally synthesized zinc oxide (ZnO) loaded mesoporous SBA‐15 hybrid nanocomposite for relative humidity sensing (RH) at room temperature. The sensor exhibits an excellent ~5 orders impedance change along with excellent linearity, quick response time (17 s), rapid recovery time (18 s), negligible hysteresis (1.2%), good repeatability, and stability (1.8%) in 11%–98% RH range. In addition, complex impedance spectra of the sensor at different RHs were analyzed to understand the humidity sensing mechanism. Our study can open a new way for realizing ZnO/SBA‐15 hybrid nanocomposite for fabrication of high‐performance RH sensors.     

Molecular mechanisms involved in creep phenomena of paper

The phenomenon of mechanosorptive creep (i.e., the increasing creep occurring in some hygroscopic materials subjected to moisture cycling) was studied for paper from a molecular point of view. Paper was tested in creep at different loading levels in a constant high humidity of 90% relative humidity (RH) and in a cyclic climate between 30 and 90% RH. Throughout the creep tests, spectra from the mid‐ and near‐IR, as well as dynamic mechanical data, were recorded to determine molecular changes occurring with time. In tensile stress scans the instantaneous, dynamic elastic modulus was found to increase. It is suggested that this increase was due to orientation of the cellulose molecules, which was detected as changes in the mid‐IR spectra at 1160 cm⁻¹ assigned to the C₁ O C₄ stretching. During creep in constant and cyclic humidity, the modulus was found to increase with time, more so for the cyclic humidity. Changes in the mid‐IR spectra at 1184 and 1030 cm⁻¹, which is assigned to CH₂, CH, and C O, may indicate sliding between the cellulose chains. The near‐IR measurements mainly showed differences in the moisture content. In stress scans the moisture content increased with increasing tensile load. In creep at constant 90% RH, the moisture content was also found to increase in a manner similar to the stress scan. In the cyclic humidity with a conditioning time of 70 min at 90% RH the moisture content decreased successively with increasing numbers of cycles. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1590–1595, 2001     

Antibacterial polycaprolactone electrospun fiber mats prepared by soluble eggshell membrane protein–assisted adsorption of silver nanoparticles

Antibacterial polycaprolactone (PCL) electrospun fiber mats were prepared by coelectrospinning PCL with soluble eggshell membrane protein (SEP) in 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP), followed by adsorption of silver nanoparticles (Ag NPs) through hydrogen‐bonding interaction between the amide groups of SEP and the carboxylic acid groups capped on the surfaces of Ag NPs. The PCL/SEP fiber mat was characterized by X‐ray photoelectron spectroscopy, indicating the presence of some SEP on the fiber surface. The adsorption of Ag NPs was confirmed by transmission electron microscopy and quantitatively characterized by thermogravimetric analysis. The pH value of the silver sol used for adsorption is very important in view of the amount and dispersion state of Ag NPs adsorbed on the fibers. The Ag NP–decorated PCL/SEP fiber mats prepared at pH 3–5 exhibit strong antibacterial activity against both gram‐negative Escherichia coli and gram‐positive Bacillus subtilis. Antibacterial PCL fiber mats were also obtained similarly with the assistance of collagen (another protein) instead of SEP, showing that protein‐assisted adsorption of Ag NPs is a versatile method to prepare antibacterial electrospun fiber mats. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43850.     

Aniline/Ag+ to polyaniline/Ag nanocomposite in the presence of sodium dodecyl sulfate and phenylene diamine

Silver ion oxidized effectively aniline monomer in the presence of p‐phenylene diamine (PDA) promoter in sodium dodecyl sulfate (SDS) micellar medium to polyaniline/silver nanocomposite (PANI/Ag). To compare the results obtained, a sample of PANI polymer lacking Ag nanoparticles was also synthesized by a similar manner using ammonium peroxydisulfate instead of silver ion as the reaction oxidant. The use of PDA promoter/SDS emulsifier system could on one hand decrease the reaction time compared to those of reported previously, and on the other hand, allow the as‐reduced silver particles to stay nanosized. The Ag‐loaded PANI nanocomposite was structurally confirmed using Fourier transform‐infrared and X‐ray diffraction techniques. The uniformly‐dispersed Ag nanospheres with average particle size of ∼20 nm were clearly detectable in the bright‐field micrographs obtained from transmission electron microscopy. Furthermore, thermogravimetric analysis showed that major losses of the mass occurred at two temperature regions including 150–375°C and 375–800°C. POLYM. COMPOS., 36:253–256, 2015. © 2014 Society of Plastics Engineers