Incorporation Of ZnO Nanoparticles Research Articles

The use of low duty cycle pulsed-unipolar current mode for producing Alumina/ZnO nanocomposite coatings via plasma electrolytic oxidation process

The incorporation of ZnO nanoparticles into plasma electrolytic oxidation coatings formed on aluminum was investigated in this work. The coating process was performed in silicate-based electrolytes containing varying amounts of ZnO nanoparticles. A current density of 5 A dm−2 with a low duty cycle of 20% and a frequency of 2000 Hz were applied to all aluminum samples. Results showed all coatings were primarily comprised of γ-Al2O3, Al2H2O12S4 (Al2O3.4SiO2.H2O) and contained ZnO nanoparticles from the electrolyte. Surface and cross-sectional elemental maps revealed that ZnO nanoparticles were distributed primarily on the coating surface and near the coating-substrate interface. It has been proposed that formation of silica insoluble gel containing entrapped ZnO nanoparticles on the coating surface is a reason of why Zn and Si were primarily concentrated in the upper parts of the coatings. Beside this, particles can only reach the inner layer of the coating through short-circuit paths formed by breakdown events. In pulsed-unipolar DC current mode with low duty cycle and corresponding large number of micro-discharges, higher number of nanoparticles can enter discharge channels and reach the inner parts of the coating. Potentiodynamic polarization test results showed embedding nanoparticles in the coating structure improves its corrosion behavior.

Zinc migration and its effect on the functionality of a low density polyethylene-ZnO nanocomposite film

Abstract The interest in incorporating ZnO nanoparticles (ZnO-NPs) into food contact materials is increasing due to its attractive functions such as ultraviolet (UV) blocking and antimicrobial activity. Despite their benefits, the stability and functionality of ZnO-NPs could be altered when they come into contact with foodstuff through migration. Hence, we investigated Zn migration and its effect on the functional properties of low density polyethylene (LDPE)-ZnO nanocomposite films. The migration of Zn from nanocomposite films into food simulants (distilled water, 4% acetic acid (w/v), 50% ethanol (v/v) and n-heptane) was conducted at 70 °C for 30 min according to the Korea standard and specifications for food utensils, containers and packages conditions. The presence of Zn in the food simulants was verified by inductively coupled plasma-optical emission spectrometry. Different concentrations of dissolved Zn were observed ranging from 0.006 to 3.416 mg L−1 (except for heptane) and the level of migrated Zn was found as a function of the ZnO-NPs content in the nanocomposite film. However, the highest amount of migrated Zn measured in this study was lower than the specific migration limit regulated by the European Commission. In addition, the UV light absorption and the antimicrobial activity of the LDPE-ZnO nanocomposite film were significantly affected by the dissolution of ZnO, particularly in acetic acid. Therefore, particular attention is requested to use when LDPE-ZnO nanocomposite films are used for food packaging, especially acidic food, because Zn can likely migrate, and thereby their UV blocking and antimicrobial functions could be no longer effective.

Sponge‐like chitosan‐based nanostructured antibacterial material as a topical hemostat

ABSTRACTIn this study, chitosan/alginic acid/zinc oxide (CHI/AA/ZnO) nanostructured hydrogel sponges were fabricated by incorporating ZnO nanoparticles (<100 nm) into polymer matrix to develop a new potential biomaterial for hemorrhage control. For this purpose, the crosslinked CHI/AA/ZnO nanostructured sponges were synthesized by freeze‐drying technique. Genipin was used as a crosslinker. The prepared chitosan‐based sponges were characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy—energy‐dispersive spectroscopy analysis. The effects of ZnO content on the physicochemical characteristics of sponge‐like nanostructured hydrogels were evaluated by swelling ratio in two different pH values. Physical immobilization of dexamethasone as a model drug in hydrogel matrix resulted sustained release of drug more than 3 days. Antibacterial activity of hydrogel sponges was assessed against Staphylococcus aureus. The cytotoxicity and hemostatic efficacy of crosslinked CHI/AA/ZnO sponge like‐nanostructured hydrogels was evaluated in vitro and in vivo, respectively. The results of this study demonstrated that the prepared CHI/AA/ZnO nanostructured sponge had the potential to be an antibacterial topical hemostat. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47522.

Zinc oxide phytase nanocomposites as contributory tools to improved thermostability and shelflife

The current study suggests the utility of ZnO nanoparticles to increase the thermotolerance of phytase enzymes; thereby aiding their effective utilization to provide better phosphate uptake when applied in animal feeds. Microbial isolates with predominant phytase activity were isolated from industrial wastewater to obtain a promising thermotolerant isolate of Penicillium decumbens. The purified phytase showed activities at mash preparatory temperature (32.59 ± 0.045 Uml−1 min−1 at 55 °C), animal feed pelletising temperature (37.83 ± 0.127 Uml−1 min−1 at 80 °C) and steam sterilization temperature (18.56 ± 0.027 Uml−1 min−1 at 100 °C) of animal feeds as per standard phytase assays. The supplementation of ZnO nanoparticles found to increase thermostability of phytase from 18.56 Uml−1 min−1 to 30.5 Uml−1 min−1 at 100 °C. The antibacterial role of the nanocomposites was checked against human pathogens to obtain satisfactory results against standard antibiotics. Thus the incorporation of ZnO nanoparticles in combination with phytase provided a dual benefit of increasing its thermostability and antimicrobial property thereby increasing its shelflife.

A Multifunctional Zinc Oxide/Poly(Lactic Acid) Nanocomposite Layer Coated on Magnesium Alloys for Controlled Degradation and Antibacterial Function

In the present work, magnesium (Mg) AZ31 alloy was coated with a multifunctional membrane layer composed of ZnO nanoparticles (NPs) embedded in a poly(lactic acid) (PLA) matrix. We aimed to produce a stable coating that would be used to control the degradation rate of the Mg alloy and promote a local antibacterial activity. ZnO NPs were dispersed at 5 and 10 wt % in a PLA solution and dip-coated onto the AZ31 substrate. Surface topography, chemical composition, thickness, electrochemical corrosion performance, mass variation, antibacterial activity, adhesion performance, and cytotoxicity of an uncoated control and coated alloys were investigated. The results indicated that the incorporation of ZnO NPs at various concentrations affords a dramatic control over surface topography and degradation rates under in vitro and in vivo environmental conditions when compared to the uncoated Mg alloy control. In addition, the results confirmed that the coated layer exerts antibacterial properties and supports cell growth, indicating this system may have utility for bone tissue engineering applications.

Incorporation of ZnO nanoparticles into heparinised polyvinyl alcohol/chitosan hydrogels for wound dressing application

Available wound dressings have some major deficiencies including low water vapor transmission rate (WVTR), low absorption of wound fluids, and not providing a suitable and moist environment for wound healing. The main advantage of hydrogels is giving aid to the creation of a moist and cool environment for wound healing and providing high water vapor permeability along with preventing penetration of microbes into the wound surface. Therefore, hydrogels of heparinized polyvinyl alcohol (PVA)/chitosan (CS)/nano zinc oxide (nZnO) were prepared to be used as wound dressing. Samples were characterized via infrared spectrometry (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, other properties including swelling ratio, water vapor transmission rate, the size of pores, mechanical and thermal properties, cell viability, and antibacterial efficiency were investigated. Water vapor permeability, porosity, and swelling ratio showed a wide range of numerical values that facilitate the use of provided samples as ideal wound dressings. Besides, investigating mechanical and thermal properties exhibited the improvement of mentioned properties by adding nano zinc oxide. Furthermore, Heparin loading was conducted on optimum samples. Heparin release rate decreased and was more sustained by adding nanoparticles compared to hydrogel wound dressings without nZnO. Cell viability of bionanocomposite samples showed no toxicity after loading nanoparticles and this value was >70% for all samples. Antibacterial properties of hydrogel samples can effectively protect wounds especially with an increase nZnO content. Hence, these hydrogels were found applicable as robust wound dressings.

High-performance one-pack ambient cross-linking latex binders containing low-generation PAMAM dendrimers and ZnO nanoparticles

This study focuses on ambient-temperature self-crosslinking acrylic latex coating compositions containing poly(amidoamine) (PAMAM) dendrimers and ZnO nanoparticles in the role of inter-particle cross-linking agents and flash rust inhibitors. Low-generation amine-terminated PAMAM dendrimers as aqueous solutions were added into latices containing diacetone acrylamide repeat units in their polymer structure. The incorporation of ZnO nanoparticles (without any surface treatment) was performed during the synthesis of a polymer dispersion carried out by the semi-continuous emulsion polymerization technique. The latex storage stability and coating performance with respect to zinc oxide and PAMAM presence were evaluated and compared with a conventional zinc oxide-free coating composition containing adipic acid dihydrazide as the cross-linking agent. It was found that the novel latices containing both PAMAM dendrimers and ZnO nanoparticles exhibited a long-term storage stability and provided crosslinked transparent coating films of high gloss, enhanced mechanical properties, solvent resistance and excellent water whitening resistance. Moreover, the latex compositions containing PAMAM dendrimers as the inter-particle cross-linkers were shown to provide flash rust resistance.

Investigations on optical properties of ZnO decorated graphene oxide (ZnO@GO) and reduced graphene oxide (ZnO@r-GO)

The present investigation is based on the production of reduced graphene oxide (r-GO) from the graphene oxide using Hummer's (GO) and improved Hummer's methods (IGO) at elaborated conditions, named as GO and IGO, respectively hereafter. In contrast to previously known techniques, the presented process does not generate toxic gas. Meanwhile, the reduction temperature can be easily controlled. This approach provides a more significant amount of hydrophilic oxidized graphene as compared to GO and IGO with the use of additional KMnO4. Thus synthesized IGO was used to produce r-GO by thermal treatment. The morphological characteristics show that the obtained samples have a wrinkled paper-like morphology with severely folded lines. However, r-GO has double layers and multilayer at the edges. All the products (GO, IGO, and r-GO) have been decorated with ZnO nanoparticles (NPs). The XRD patterns of ZnO@GO composites have confirmed the characteristic peaks of wurtzite ZnO indicating the formation of ZnO nanoparticles onto the surface of graphene. The microscopic studies confirm the random growth/decoration of ZnO NPs on the surface of GO/IGO/r-GO sheets. However, in IGO and r-GO, loading/growth of ZnO NPs are less as compared to ZnO@GO. Overall structural studies indicate the oxidation of graphite and reduction of graphene oxide into r-GO sheets and ZnO decoration. Upon UV excitations, a bright blue emission has been exhibited by the GO that originates from geminate recombination of localized e-h pairs in sp2 clusters those primarily act as the luminescent centers. The noteworthy enhancement in the emission intensities after the incorporation of ZnO nanoparticles on the surface of GO is observed. The improved synthesis method and low-temperature reduction technique of GO may be essential for the large-scale production of r-GO as well as the construction of devices composed of ZnO@GO/IGO/r-GO.

Study of the effect of ZnO nanoparticles addition to PEO coatings on pure titanium substrate: Microstructural analysis, antibacterial effect and corrosion behavior of coatings in Ringer's physiological solution

In this work, a phosphate-based electrolyte, containing ZnO nanoparticles in concentrations of (0, 5, 10, and 15 g/L), was used to achieve coatings on pure titanium by using plasma electrolytic oxidation (PEO) method. Microstructure, phases, and chemical compositions of the coatings were investigated using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) pattern and energy dispersion spectroscopy (EDS), respectively. In order to investigate the corrosion behavior, the samples were dipped in Ringer’s solution, and then potentiodynamic polarization test and electrochemical impedance spectrometry (EIS) were performed. Incorporation of ZnO nanoparticles into the coatings resulted in reduction in the number of pores, and modification of the coating microstructure, which consequently increased corrosion resistance. Also, addition of ZnO nanoparticles resulted in a decrease in the corrosion current density (93% reduction for the sample containing 15 g/L ZnO nanoparticles) in comparison with the uncoated titanium substrate. The results of antibacterial tests revealed that ZnO nanoparticles were able to effectively retain the Gram-positive and Gram-negative bacterial activities, and also, by increasing the concentration of nanoparticles, the intensity of antibacterial effect of the coating was increased.

Nanocomposite films based on CMC, okra mucilage and ZnO nanoparticles: Physico mechanical and antibacterial properties

This work examined the physico mechanical parameters and antibacterial activity of CMC/okra mucilage (OM) blend films containing ZnO nanoparticles (NPs). Different proportions of CMC and okra mucilage (100/0; 70/30; 60/40 and 50/50 respectively), were mixed and casted to posterior analysis of formed films. The more colored films were obtained by higher contents of okra mucilage and adding ZnO nanoparticles. The incorporation of ZnO NPs into CMC film decreased the elongation at the break (EB) value of the films and increased the tensile strength (TS) value of the film. With increase in CMC concentration in the films, higher water vapor permeability and higher solubility in water were achieved. Microstructure analysis using SEM showed a smooth and compact surface morphology, homogeneous structure, and a rough surface for CMC, CMC+ZnO, and CMC/OM30%+ZnO, respectively. Nanocomposite films presented antibacterial activity against tested bacteria. Films contained okra mucilage showed more antibacterial activity. The inhibitory activities of resultant films were stronger against S. aureus than E. coli.

H2S Removal Using ZnO/SBA-3: New Synthesis Route and Optimization of Process Parameters

H2S is a major toxic compound that could be found in air, water, Fossil fuels and causes some worse effects such as acidic rain and corrosion. In the present work SBA-3 (Santa BarbarA University no. 3) with three different weight percent’s of ZnO, i.e. 5%, 10% and 15% was synthesized via an in situ approach. All synthesized samples were characterized using atomic absorption spectrometry, X-ray diffraction (XRD), nitrogen adsorption and transmission electron microscopy (TEM). The obtained results from XRD and nitrogen adsorption confirmed that all the samples almost retained their ordered structure after incorporation of ZnO nanoparticles within the mesopores of SBA-3. TEM images show that ZnO nanoparticles arranged along the direction of mesopores of SBA-3. Then, adsorption of H2S from a model gas was investigated. A three factor Box–Behnken design with five center points and one response was performed for the evaluation of effect of three process parameters, i.e. ZnO wt%, space velocity and temperature on the adsorption of H2S and a quadratic model (r2 : 0.9185) was developed to navigate the design space. Temperature had the largest and space velocity had the lowest effect on the breakthrough of H2S. The optimum breakthrough time (tbp) was 588 min.

Effects of PLA Film Incorporated with ZnO Nanoparticle on the Quality Attributes of Fresh-Cut Apple.

A novel nanopackaging film was synthesized by incorporating ZnO nanoparticles into a poly-lactic acid (PLA) matrix, and its effect on the quality of fresh-cut apple during the period of preservation was investigated at 4 ± 1 °C for 14 days. Six wt % cinnamaldehyde was added into the nano-blend film. Scanning electron microscope (SEM) analysis showed a rougher cross-section of the nano-blend films and an X-ray diffraction (XRD) was carried out to determine the structure of the ZnO nanoparticles. Compared to the pure PLA film, the nano-blend film had a higher water vapor permeability (WVP) and lower oxygen permeability. With the increase of the nanoparticles (NPs) in the PLA, the elongation at break (ε) and elastic modulus (EM) increased, while tensile strength (TS) decreased. Thermogravimetric analysis (TGA) presented a relatively good thermostability. Most importantly, the physical and biochemical properties of the fresh-cut apple were also measured, such as weight loss, firmness, polyphenol oxidase (PPO), total phenolic content, browning index (BI), sensory quality, and microbiological level. The results indicated that nano-blend packaging films had the highest weight loss at the end of storage compared to the pure PLA film; however, nanopackaging provided a better retention of firmness, total phenolic countent, color, and sensory quality. It also had a remarkable inhibition on the growth of microorganisms. Therefore, Nano-ZnO active packaging could be used to improve the shelf-life of fresh-cut produce.

Sepiolite nanoplatform for the simultaneous assembly of magnetite and zinc oxide nanoparticles as photocatalyst for improving removal of organic pollutants

Novel ternary ZnO/Fe3O4-sepiolite nanostructured materials were developed in a two-step procedure based on the incorporation of ZnO nanoparticles on a substrate composed by magnetite nanoparticles previously assembled to the sepiolite fibrous silicate (Fe3O4-sepiolite). The structural and morphological characterization shows that both, ZnO and Fe3O4 nanoparticles, were homogeneously dispersed on the surface of sepiolite. Therefore, the resulting material is characterized as a multifunctional nanoplatform simultaneously providing magnetic and photoactive properties. ZnO/Fe3O4-sepiolite materials exhibit superparamagnetic properties at room temperature, which is one of the sought properties in view to facilitate their recovery from the reaction medium after application as heterogeneous catalysts. ZnO/Fe3O4-sepiolite materials were tested as photocatalysts using methylene blue dye in water as model of a pollutant molecule, showing full decolorization after 2h of UV irradiation. Moreover, the photocatalytic activity of this nanoplataform may be maintained after reuse in several consecutive cycles of treatment. Remarkably, the ZnO/magnetite-sepiolite nanostructured material displays a similar activity as ZnO/sepiolite materials, but shows the additional advantage of easier recovery by means of a magnet which facilitates its reuse.

Effective incorporation of ZnO nanoparticles by miniemulsion polymerization in waterborne binders for steel corrosion protection

A nanohybrid waterborne binder was synthesized by miniemulsion polymerization with the incorporation of ZnO nanoparticles in order to increase the corrosion protection capability. This system was compared to a neat waterborne binder and to a physical blend of the binder with an aqueous ZnO nanoparticles dispersion. The hybrid dispersion was characterized by SEM and TEM, while the corrosion behavior of these latexes was investigated by electrochemical measurements (open circuit potential and electrochemical impedance spectroscopy in 3.5 wt% NaCl solution), evaluating the effect of the incorporation of these nanoparticles into the polymeric matrix. The incorporation of ZnO nanoparticles by blending showed similar behavior to the neat coating despite flash rust reduction on the metal surface. In contrast, the hybrid binder prepared by miniemulsion polymerization has shown the best performance according to the values of pore resistance (R i ) and coating capacitance (C c). In general, this study shows how useful can be the miniemulsion polymerization methodology to design hybrid coating formulations, obtaining homogenous distribution of ZnO nanoparticles within the film. Indeed, a heterogeneous distribution can hinder the effectiveness and the corrosion protection capabilities of promising nanoparticles.

Effects of ZnO particles on space charge of EVA copolymer for HVDC cable accessory insulation

The performance of cable accessories, as an essential part of the HVDC networks, is a great concern to the reliability of the system. Cable accessories made of ethylene-vinyl acetate copolymer (EVA) by incorporation of specific fillers have to face the problem of space charge accumulation and become more unpredictable considering the complex conditions. The effects of doping contents on the space charge behaviors of EVA/ZnO composite are not completely clear, which need further investigation. In this paper, EVA composites were prepared by incorporating ZnO nanoparticles into EVA matrix with fraction of 0, 1, 5 and 10 wt% respectively, with which 5 wt% nano-sized plus 5 wt% micro-sized ZnO doped samples were chosen for comparison. The dependence of dielectric properties and conduction current on the doping contents was measured. PEA method was applied to research the space charge behaviors of EVA composites under -25 kV/mm. Obtained results show that the particles in EVA composite are in homodisperse. The permittivity is increased by ZnO doping and the dissipation factor of EVA composites with 1 and 5 wt% nanoparticles is lower at the lower frequencies. The homocharges injection occurs in cathode instead of anode when ZnO nanoparticles are introduced and 5 wt% nanoparticles doping performs well in suppressing space charge injection. The electric field of the 5 wt% nanoparticles doped EVA distributes more uniformly under the high electric stress than that of others. During the depolarization procedure, the total remnants charges of 10 wt% doped samples are the least in the final. The above results are well explained by the DC conduction, apparent mobility and trap distribution characteristics. The micro-sized ZnO particles may break the chains and produce new defects, which will act as local deep traps.

Comparative effects of untreated and 3-methacryloxypropyltrimethoxysilane treated ZnO nanoparticle reinforcement on properties of polylactide-based nanocomposite films

Polylactide (PLA) nanocomposites characterized by antimicrobial properties are gaining increasing attention for food packaging. In this contribution, the PLA based nanocomposite films with multifunctional end-use properties were achieved by incorporating ZnO nanoparticles (NPs) [untreated: ZnO(UT) and 3-methacryloxypropyltrimethoxysilane treated: ZnO(ST)] into polymer matrix via solvent casting method. The ZnO(ST) prevented the degradation of PLA at higher temperature and improved the mechanical property. Color, transparency, and anti-UV properties of composite films were influenced by the incorporation of ZnO NPs. Contrary to untreated ZnO, the treated NPs were more effective in enhancing the tortuosity of the diffusive path for the oxygen molecules to diffuse through the film. The glass transition (Tg) and crystallization (Tc) temperatures of composites were improved by the addition of ZnO, whereas a higher Tg was recorded for ZnO(ST) loaded films. XRD demonstrated the change in crystallinity of the films with NPs addition. Nanoparticles well distributed in the composite films as observed through SEM however spots of agglomeration were observed for PLA/ZnO(UT) films. Developed films especially incorporated with ZnO(ST) were found to be active against both Gram-negative (Salmonella Typhimurium) and Gram-positive (Listeria monocytogenes) bacteria. Therefore, PLA/ZnO nanocomposite films could be considered as environment-friendly active packaging material for food preservation.

Combustion of stable water-in-diesel emulsion fuel and performance assessment

ABSTRACTThe use of water-in-diesel (W/D) emulsion fuel has an optimistic influence in promoting lower levels of NOx and PM emissions with improved engine performance. Concurrently, rough engine operation is perceived with W/D emulsion fuels due to the longer ignition delay period, resulting in the high rate of pressure rise at a later degree of CA. The present study focuses on achieving a shorter ignition delay period in W/D emulsion fuel by incorporating ZnO nanoparticles. Experiments were conducted in two phases. In the first phase, stable W/D emulsion fuels with different mass fractions of nanoparticle (5W/D, 10W/D, 10W/D50ZnO, and 10W/D100ZnO) were synthesized and their properties were measured. In the second phase, experiments were conducted in a single-cylinder, four-stroke diesel engine under different engine load conditions to study the combustion and performance characteristics of the above-mentioned sample fuels. The results of this study showed that the physico-chemical properties of W/D emulsion fuels and nano-incorporated W/D emulsion fuels meet the standard diesel fuel specifications with an acceptable emulsion stability period. In addition, W/D emulsion fuels with ZnO incorporated blend reduce the ignition delay period and promote a better level of combustion and performance levels over BD and W/D emulsion fuels.

Dependence of Carrier Transport of [6,6]-phenyl C61-butyric Acid Methyl Ester/p-Type Si Diodes upon Incorporation of ZnO Nanoparticles

In this study, the effect of the incorporation of ZnO nanoparticles into [6,6]-phenyl C61-butyric acid methyl ester (PCBM) on carrier transport of PCBM/p-type Si diodes was examined. Correlation effects were evaluated using the well-known expressions for the thermionic emission and space charge limited current. Rectification behavior is affected by the bulk effects of the PCBM layer. It is shown that the incorporation of ZnO nanoparticles leads to the suppression of trap filling effects of the PCBM layer, resulting in improvement in the electrical and optoelectronic performances for PCBM/p-type Si diodes.

The thermal, optical, flame retardant, and morphological consequence of embedding diacid‐capped ZnO into the recycled PET matrix

ABSTRACTWe extended our work to a fast and facile nanocomposites (NCs) manufacturing by incorporation of ZnO nanoparticles (NPs) on to a recycled poly(ethylene terephthalate) PET as a polymer matrix prepared by a dissolution/reprecipitation method. The surface of ZnO NPs was functionalized with synthesized optically active diacid containing alanine amino acid. Organo‐modified NPs which provided using solution blending technique through ultrasonic irradiation, were embedded into recycled PET. PET@ZnO/DA NCs containing different loadings of functionalized NPs (1, 3, 5 wt %) were investigated by thermal gravimetric analysis, field emission scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, Fourier transform infrared spectroscopy and UV–visible spectroscopy. Morphological studies revealed uniformly dispersed ZnO/DA NPs in the polymer matrix. The crystalline nature of PET slightly improved as a function of the NPs concentration. Char yield in TGA and LOI values indicated that the obtained NCs were capable of exhibiting flame retardant properties. The NCs were found to exhibit more absorbance in the UV and visible region in compare to the neat PET. The effect of ultrasonication in different solvent on the morphology of the recycled polymer particle was also studied. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43433.

Amelioration of anticorrosion and hydrophobic properties of epoxy/PDMS composite coatings containing nano ZnO particles

Epoxy-polydimethylsiloxane (PDMS) nanocomposite coatings loaded with different concentrations (ranged from 2 to 8% (w/w)) of ZnO nanoparticles have been successfully achieved by using the solution intercalation method. In this study, it has been aimed to investigate corrosion protection performance and hydrophobic properties of epoxy/PDMS nanocomposites (NC). Fourier transform infrared (FTIR) spectroscopy was utilized in order to study the chemical structure of the developed coatings. The coating surface wettability was studied by contact angle measurements and the dispersion of ZnO nanoparticles was examined via field emission scanning electron microscope (FESEM). The effects of ZnO nanoparticles on the corrosion resistance and the barrier performance were investigated by electrochemical impedance spectroscopy (EIS). Thermal properties were evaluated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) From the FTIR spectra it was observed that the incorporation of nano ZnO particles has demonstrated peak shift and change in intensity. The incorporation of nano ZnO particles within the hybrid polymeric matrix had improved the hydrophobicity in terms of contact angle which reached maximum as 128° for NC6 system. NC2 coating had shown higher coating resistance more than 109 Ω even after 30 days of exposure in electrolyte medium. The results obtained from TGA and DSC studies demonstrated that introducing PDMS to epoxy resin increased Tg whereas the incorporation of ZnO nanoparticles in the nanocomposite coatings showed reduction in degradation temperature, cross-linking density of the composite by lowering Tg.