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1.
Surfaces with antibacterial and antistatic functionalities are one of the new demands of todays' industry. Therefore, a facile method for the preparation of multifunctional polyaniline/copper/TiO2 (PANI/Cu/TiO2) ternary nanocomposite based on in situ polymerization is presented. This nanocomposite was characterized through the different techniques and was utilized for induction of antibacterial and antistatic properties in polyurethane coatings. Measurement of the conductivity of PANI/Cu/TiO2 ternary nanocomposite indicated higher electrical conductivity of this nanocomposite compared to pure PANI. The antibacterial activity of the modified polyurethane coatings was tested against Gram-positive and Gram-negative bacteria which led to remarkable reduction in bacterial growth. Besides, it was observed that polyurethane coating with 2 wt % content of ternary nanocomposite has a surface electrical resistance equal 4 × 108 Ω/sq which acquires surface electrical resistance of standard antistatic coatings. The final coatings were also characterized in terms of thermal and mechanical properties to investigate the effect of the ternary nanocomposite on improvement of these properties. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48825.  相似文献   

2.
Different types of composite coatings were prepared by the blending of colloidal nanosilica (SiO2) and titanium dioxide (TiO2) in epoxy resin to investigate their coating performances. A fixed amount of silica nanoparticles (20 wt %) and different amounts (5, 10, and 15 wt %) of microsized TiO2 particles were used in the coatings. The functional groups of the formulated coatings were confirmed by Fourier transform infrared spectroscopy. These results indicate that the SiO2–TiO2 particles interacted well with epoxy. Scanning electron microscopy images of the composite coatings revealed a good dispersion of TiO2 particles at a lower amount of loading; this improved the adhesiveness, glass-transition temperature, thermal stability, and chemical resistance properties. At higher loadings, the performances decreased. The composite coatings were also characterized by their UV radiation-absorption properties with an ultraviolet–visible spectrophotometer. Interestingly, this property was found to be enhanced at higher loadings. An impressive result was noticed in the nanocomposites in terms of oxygen transmission rate performance compared to that of the neat epoxy. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47901.  相似文献   

3.
We prepared titanium dioxide/PVA nanocomposite fiber webs for application in multifunctional textiles by electrospinning. The morphological properties of the TiO2/PVA nanocomposite fibers were characterized using scanning electron microscopy and transmission electron microscopy. Layered fabric systems with electrospun TiO2 nanocomposite fiber webs were developed using various concentrations of TiO2 and a range of web area densities, and then the UV‐protective properties, antibacterial functions, formaldehyde decomposition ability, and ammonia deodorization efficiency of the fabric systems were assessed. Layered fabric systems with TiO2 nanocomposite fiber webs containing 2 wt% TiO2 nanoparticles at 3.0 g m?2 web area density exhibited an ultraviolet protection factor of greater than 50, indicating excellent UV protection. The same system showed a 99.3% reduction in Staphylococcus aureus. Layered fabric systems with TiO2 nanocomposite fiber webs containing 3 wt % TiO2 nanoparticles at 3.0 g m?2 web area density exhibited a 85.3% reduction in Klebsiella pneumoniae. Titanium dioxide nanocomposite fiber webs containing 3 wt % TiO2 nanoparticles at 3.0 g m?2 web area density exhibited a formaldehyde decomposition efficiency of 40% after 2 h, 60% after 4 h, and 80% after 15 h under UV irradiation. The same system showed an ammonia deodorization efficiency of 32.2% under UV irradiation for 2 h. These results demonstrate that TiO2 nanocomposite fibers can be used to produce advanced textile materials with multifunctional properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012  相似文献   

4.
《Ceramics International》2019,45(11):13747-13760
TiO2-rGO nanocomposite coatings were obtained by electrophoretic deposition (EPD) technique of TiO2 nanoparticles and graphene oxide (GO) on stainless steel substrate. First, GO particles were synthesized using a modified Hummers' method. GO was reduced electrochemically to form a coating in the presence of nano-sized TiO2 particles. The influences of different parameters such as GO concentration, coupling co-electro-deposition parameters (electrophoretic duration and voltage) on thickness, surface morphology and, corrosion behavior of the as-synthesized TiO2-rGO nanocomposite coatings were systematically surveyed. The morphology and microstructure were investigated by field emission scanning electron microscopy (FE-SEM), Raman spectra and X-ray diffraction (XRD) techniques. Atomic force microscopy (AFM) was harnessed to evaluate the topography of the as-prepared GO powder. The bonding characteristics of as-synthesized and as-reduced GO were examined after deposition, by Energy Dispersive Analysis of X-Ray (EDX) and Fourier-transform infrared spectroscopy (FT-IR). Corrosion behavior of coatings and that of the pure TiO2 layer were evaluated by electrochemical impedance spectroscopy (EIS) and polarization techniques (by applying potentiodynamic polarization spectroscopy (PDS)). Detailed SEM studies showed that increasing EPD voltage brings about a coating with increased porosity and microcracks with higher thickness. In addition to that, the presence of rGO reduced corrosion current density (icorr) and shifted corrosion potential (Ecorr) toward more noble values in 3.5% NaCl at room temperature. Also, Analyses revealed that the optimum electrophoretically synthesized coating was obtained at GO concentration of 1 g/L, 30 V and 30 min at room temperature. The corrosion current density of the corresponding coating was remediated up to 0.2 μA cm−2, which means an anti-corrosion ability of about 30 times compared to TiO2-coated and bare 316L stainless steel. The results of impedance spectroscopic studies demonstrated that this coating renders as a barrier layer and resistance increased from 2.95 KΩ cm2 for TiO2-coated layer to 10.49 KΩ cm2 for the optimized layer.  相似文献   

5.
In this study, the effects of multi‐walled carbon nanotubes (MWCNT), and its hybrids with iron oxide (Fe2O3) and copper oxide (CuO) nanoparticles on mechanical characteristics and thermal properties of epoxy binder was evaluated. Furthermore, simultaneous effects of using MWCNT with TiO2 as pigment and CaCO3 as filler for epoxy composites were determined. To investigate effects of nano‐ and micro‐particles on epoxy matrix, the samples were evaluated by TGA and DTA. It was found that the hybrid of MWCNT with nano metal oxides caused considerable increment in the tensile and flexural properties of epoxy samples in comparison to the single MWCNT containing samples at the same filler contents. Significant improvement in the thermal conductivity of epoxy samples was obtained by using TiO2 pigment along with MWCNT. The TiO2 pigment also caused considerable improvement in mechanical properties of the epoxy matrix and the MWCNT containing nanocomposite. The best mechanical and thermal properties of epoxy nanocomposites were obtained at 1.5 wt % of MWCNT and 7 wt % of TiO2 that it should be attributed to particle network forming of the particles which cause better nano/micro dispersion and properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43834.  相似文献   

6.
ZnO–TiO2, SiO2–TiO2, and SiO2–TiO2–ZnO hybrid nanocomposite coatings were synthesized based on sol–gel precursors including tetramethoxysilane (TMOS), 3-glycidoxypropyl trimethoxysilane (GPTMS), tetra(n-butyl orthotitanate) (TBT), and zinc acetate dihydrate. The hybrid network was characterized by FTIR, FESEM, and EDAX techniques. Results indicated that inorganic particles’ size was of nanoorder (20–30 nm), with very uniform distribution and dispersion. Photocatalytic and self-cleaning activities of these coatings were further investigated by degradation of methylene blue in an aqueous solution (20 ppm) at visible light irradiation, indicating photocatalytic performance of the coatings containing ZnO and TiO2 nanoparticles. The antibacterial effect of the coatings was investigated for inhibition and inactivation of cell growth, with the results showing the same antibacterial activity for ZnO–TiO2 and SiO2–TiO2–ZnO coatings against Escherichia coli and Staphylococcus aureus; the activity was, however, higher than that of SiO2–TiO2 hybrid nanocomposite coatings.  相似文献   

7.
Epoxy resin/CaCO3 nanocomposites were prepared by the methods of extruding, solution blending, and in situ and inclusion polymerization, respectively. The contents of nanoparticles in the nanocomposites were varied from 5 wt % to 15 wt %. Powder coatings with different content of nanoparticles were made from the nanocomposites. The results showed that the cupping property and impact resistance decreased with the increase of coating film thickness. The dispersion of nanoparticles in epoxy matrix affected the impact resistance and cupping property of the obtained coating films greatly. The coating films made from the nanocomposite prepared by in situ and inclusion polymerization showed that the best impact resistance and the maximum cupping property was achieved when nano‐CaCO3 content was 5 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2656–2660, 2006  相似文献   

8.
《Ceramics International》2021,47(23):33413-33425
In this research, Plasma Electrolytic Oxidation technique was used to incorporate ZnO–ZrO2 nanoparticles into TiO2 ceramic coating on Ti6–Al–4V using sodium phosphate as an electrolyte. The effect of adding these nanoparticles on corrosion, morphology, wettability and antibacterial properties in the simulated body fluid (SBF) solution was investigated. The results indicated nanoparticles modified the microstructure of coating, which increased corrosion resistance 12 times higher than that of substrate. Besides, ZrO2 nanoparticles had the most significant effect on increasing the contact angle. In addition, due to the compatibility of zirconium and zinc oxides with human body environment, the antibacterial properties of coatings were significantly improved.  相似文献   

9.
In the present investigation, at first, the surface of titanium dioxide (TiO2) nanoparticles was modified with γ-aminopropyltriethoxy silane as a coupling agent. Then a new kind of poly(vinyl alcohol)/titanium dioxide (PVA/TiO2) nanocomposites coating with different modified TiO2 loading were prepared under ultrasonic irradiation process. Finally, these nanocomposites coating were used for fabrication of PVA/TiO2 films via solution casting method. The resulting nanocomposites were fully characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), thermogravimetric analysis/derivative thermal gravimetric (TGA/DTG), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The TEM and SEM results indicated that the surface modified nanoparticles were dispersed homogeneously in PVA matrix on nanoscale and based on obtained results a possible mechanism was proposed for ultrasonic induced nanocomposite fabrication. TGA confirmed that the heat stability of the nanocomposite was improved. UV–vis spectroscopy was employed to evaluate the absorbance and transmittance behavior of the PVA/TiO2 nanocomposite films in the wavelength range of 200–800 nm. The results showed that this type of films could be used as a coating to shield against UV light.  相似文献   

10.
《Ceramics International》2015,41(4):5341-5347
A newly developed hydrophobic composite coating was fabricated by incorporating modified TiO2 nanoparticles and hydrophobic material polytetrafluoroethylene (PTFE) micropowders dispersed in fluorocarbon resin. Moreover, the surface characteristics and self-cleaning properties of the newly developed composite material were examined. The material was found to exhibit sufficient hydrophobicity with a water contact angle of 133°. The surface free energy of the composite coating was 4.11 mJ/m2. Scanning electron microscopy results revealed a micro/nanocomposite structure composed of PTFE micropowders and TiO2 nanoparticles, which was verified by X-ray photoelectron spectroscopy results. Through ultraviolet irradiation the modified TiO2-PTFE/FEVE composite coating successfully removed oleic acid absorbed on its surface. These results showed that the functional composite coating had a sufficiently hydrophobic surface with an efficient self-cleaning effect.  相似文献   

11.
A quasi-solid-state electrolyte for the dye-sensitized solar cells was prepared following the phase inversion process. The microporous polymer electrolyte based on poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) hybrid with different amount of TiO2 nanoparticles were prepared. The surface morphologies, the differential scanning calorimetry, and the ionic conductivity of the microporous polymer electrolyte were tested and analyzed. The results indicated that the microporous polymer electrolyte with TiO2 nanoparticles modification exhibited better ionic conductivity compared with the original P(VDF-HFP) polymer electrolyte. The optimal ionic conductivity of 0.8 mS cm−1 is obtained with the 30 wt % TiO2 nanoparticles modification. When assembled with the 30 wt % TiO2 nanoparticles modified quasi-solid-state electrolyte, the dye-sensitized TiO2 nanocrystalline solar cell exhibited the light to electricity conversion efficiency of 2.465% at light intensity of 42.6 mW cm−2, much better than the performance of original P(VDF-HFP) microporous polymer electrolyte DSSC. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008  相似文献   

12.
The elongational flow properties of TiO2 nanoparticle/polypropylene (PP) nanocomposite fibers were studied via melt spinning. The diameter, tension, and flow rate of fibers were directly measured and used to calculate the apparent elongational viscosity and apparent elongational strain rate using Cogswell’s theory. Thermal gravimetric analysis (TGA) was used to demonstrate that the TiO2 nanoparticles improved the thermal stability of the PP fibers. With a 1–3 wt % loading of the TiO2 nanoparticles, the PP fiber decomposition temperatures ranged from 338 °C for the pristine polymer to 342, 349, and 367 °C; the decomposition was accompamied by an initial 95 wt % weight loss. In addition, the well-distributed morphology of the TiO2 nanoparticles on the side surface of the PP matrix was observed using atomic force microscopy (AFM). At 1 wt % loading of the TiO2 nanoparticles, the surfaces of the PP nanofibers contained mono-disperse nanoparticles with sizes of 20–50 nm. Furthermore, the TiO2 nanoparticle/PP nanocomposite fibers were shown to be thermally stable and are suitable for application as an antibacterial polymer.  相似文献   

13.
It has been shown that incorporation of TiO2 nanoparticles into hydrophobic coatings can show self-cleaning performance. Accelerated laboratory testing indicated that the coats retain their hydrophobic nature for an extended time period. In this paper, hydrophobic polydimethylsiloxane (PDMS)/TiO2 nanocomposite coatings with a TiO2 content of 0–40% were fabricated by simple blending of a PDMS dispersion with an aqueous TiO2 nanoparticle dispersion. Their long-term hydrophobicity and self-cleaning performance were investigated both in laboratory and real-world outdoor testing. As expected, TiO2 nanoparticle-based coatings exhibited better self-cleaning relative to the TiO2-free PDMS control coating as measured by methylene blue degradation testing. Excellent long-term hydrophobicity was observed in accelerated weathering testing when they contained the appropriate levels of TiO2 nanoparticles (i.e., 0–30%). However, the same PDMS/TiO2 coatings did not show self-cleaning performance, and instead, exhibited improved dirt pickup resistance, in outdoor exposure testing. Sustained hydrophobicity was observed in outdoor exposure testing for the clear films except when TiO2 levels were at 40%. The hysteresis of water contact angle (HWCA) significantly increased for the PDMS control coating, and water beading was lost as the film surface picked up dirt. In contrast, the TiO2-based coatings with appropriate TiO2 levels maintained a relatively low HWCA after outdoor exposure and no water sheeting on rainy days was observed. This result demonstrates that while photocatalytic TiO2 nanoparticles can maintain coating hydrophobicity upon outdoor exposure, long-term self-cleaning performance in polluted environments has not yet been achieved with this type of coating under real-world conditions.  相似文献   

14.
《Ceramics International》2022,48(8):10629-10637
In this research, nano-ZrO2/TiO2 composite coatings were designed for titanium alloys by the in-situ incorporation of ZrO2 nanoparticles into a TiO2 ceramic coating. Precise control over the content and structure of nano-ZrO2 in this nanocomposite coating was achieved by manipulating the pH of the electrolyte during plasma electrolytic oxidation (PEO). The synthesis process and mechanism of tetragonal zirconia (t-ZrO2) were revealed by analyzing the phase composition and microstructure of the coating. The influence of pH on the formation of t-ZrO2 was also revealed. By detecting changes in the electrolyte solute composition before and after PEO, the Zr(OH)4 precursor was determined to be the source of the t-ZrO2 nanoparticles in the composite coating. The yield of t-ZrO2 in the composite coating increased upon increasing the pH of the electrolyte. Moreover, the thermal shock tests showed that increasing the t-ZrO2 content remarkably improved the thermal resistance of the coatings. This strategy and the research outcomes are expected to have great significance for developing advanced nanocomposite coatings on titanium alloys with enhanced thermal shock resistance.  相似文献   

15.
In this study, epoxy powder as a matrix was combined with different contents of silicon–aluminum–oxygen–nitrogen (SiAlON) nanoparticles using a planetary ball mill. Pure epoxy and nanocomposite powders were applied on the surface of plain carbon steel components by the electrostatic spraying method. Curing of the coatings was done in an oven or microwave for the appropriate time. The coating structure and morphology of the SiAlON nanoparticles were studied by scanning electron microscopy and transmission electron microscopy, respectively. The corrosion properties of the coatings were assessed by immersion, Tafel polarization, and electrochemical impedance spectroscopy tests in 3.5% NaCl solution. The results show that addition of 10 wt % SiAlON nanoparticles markedly increases the corrosion resistance of epoxy coatings. Thus, it can be inferred that the corrosion rate of these coatings is 15 to 18 times lower than that of pure epoxy samples and 8 to 11 times lower than coatings with 20 wt % SiAlON. The higher corrosion resistance of nanocomposite coatings can be attributed to the barrier properties of SiAlON nanoparticles. The tribological performance of the coatings was studied with the pin‐on‐disk test. The results of wear testing show that the samples containing 10 wt % SiAlON provide about five times more wear resistance than pure ones and about two times more than coatings with 20 wt % SiAlON. However, the coefficient of friction for nanocomposite coatings is reduced about 50% compared to the pure sample. Also, the curing process in either regime (oven or microwave) has the same effect on the corrosion and wear properties, and the coatings are completely crosslinked. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43855.  相似文献   

16.
Chemical oxidative polymerization of aniline (AN) and o-toluidine (OT) for the synthesis of copolymer, Poly(AN-co-OT) and its composite with TiO2 nanoparticles, Poly(AN-co-OT)/TiO2 employing ammonium persulfate as an oxidant and HCl as an external dopant were carried out. The homopolymers, Polyaniline and Poly(o-toluidine) were also prepared by following similar method. The synthesized polymers were characterized with FTIR spectroscopy, XRD/SEM/TEM analysis. The anticorrosive coatings were synthesized in dimethyl sulfoxide solution by dissolving synthesized polymers, and then were applied on low-carbon steel (LCS) samples using epoxy binder. The anticorrosive potential of the polymer coatings containing copolymer, copolymer-nanocomposite and homopolymers on LCS was evaluated in 3.5% NaCl at a temperature of 30?°C by open circuit potential, electrochemical impedance spectroscopy and potentiodynamic polarization measurements. It was observed that the nanocomposite coating increases the protection efficacy by providing better barrier properties against corrosion as compared with neat copolymer and homopolymers coatings. The morphology of the coatings before and after 60 days LCS immersion in 3.5% NaCl solution was determined using SEM.  相似文献   

17.
《Ceramics International》2020,46(9):13527-13538
Ni–based composite coatings with different amounts of TiO2–ZnO were fabricated by atmospheric plasma spraying (APS) to protect GH4169 superalloy substrates against excess wear and friction at elevated temperatures. In addition, the influence of the simultaneous addition of the oxides on the microstructure, microhardness, and wear behaviour was investigated. According to the results, the simultaneous addition of TiO2/ZnO provides anti-friction and wear inhibition over 600 °C. In particular at 800 °C, the TiO2–ZnO/Ni–5wt.%Al composite coating (10 wt% TiO2 and 10 wt% ZnO were incorporated within Ni–5wt.%Al matrix) exhibits a superior lubricity and wear resistance compared to the Ni–5wt.%Al based coatings. The XRD, Raman, and TEM characterisations reveal the formation of a glaze oxide layer consisting of NiO, TiO2, ZnO and the in-situ production of ternary oxide (Zn2TiO4), which was primarily responsible for the tribological performance of the sliding wear contacts at the specific temperature.  相似文献   

18.
This paper reports the development of a high-impact epoxy nanocomposite toughened by the combination of poly(acrylonitrile-co-butadiene-co-styrene) (ABS) as thermoplastic, clay as layered nanofiller, and nano-TiO2 as particulate nanofiller. Response surface methodology (RSM) was applied for optimization and modeling of the impact strength of epoxy/ABS/clay/TiO2 quaternary nanocomposite. A second-order mathematical model between the response (impact strength) and variables (ABS, clay and nano-TiO2 contents) was derived. Analysis of variance (ANOVA) showed a high coefficient of determination value (R 2 = 98%). Under optimum conditions, maximum impact strength of 29.2 KJ/m2 with 197% increase compared to neat epoxy was experimentally obtained. Also correlation between morphology and impact strength of the nanocomposite was investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). A dispersion of exfoliated clay platelets, TiO2 nanoparticles with low agglomeration and ABS nanoparticles was obtained as morphology of the nanocomposite. A new and more effective method for impact toughening of epoxy was introduced. This study clearly showed that the addition of the combination of layered and particulate nanofillers along with ABS as thermoplastic has a considerable enhancement effect on impact strength of epoxy.  相似文献   

19.
TiO2-graphene nanocomposite was prepared by hydrolysis of titanium isopropoxide in colloidal suspension of graphene oxide and in situ hydrothermal treatment. It provides an efficient and facile approach to yield nanocomposite with TiO2 nanoparticles uniformly embedded on graphene substrate. The electrochemical behavior of adenine and guanine at the TiO2-graphene nanocomposite modified glassy carbon electrode was investigated. The results show that the incorporation of TiO2 nanoparticles with graphene significantly improved the electrocatalytic activity and voltammetric response towards these species comparing with that at the graphene film. The TiO2-graphene based electrochemical sensor exhibits wide linear range of 0.5–200 μM with detection limit of 0.10 and 0.15 μM for adenine and guanine detection, respectively. The excellent performance of this electrochemical sensor can be attributed to the high adsorptivity and conductivity of TiO2-graphene nanocomposite, which provides an efficient microenvironment for electrochemical reaction of these purine bases.  相似文献   

20.
This study describes the effects of the addition of inorganic nanosized UV absorbers on physico-mechanical and thermal properties of an exterior commercial acrylic-based waterborne stain for wood. Electronic microscopy and water vapor (WV) permeability measurements were performed to characterize the free films of the acrylic stain and resulting nanocomposite coatings. An accelerated weathering method was used to evaluate aging behavior of the coatings on wood through appearance, Tg, abrasion resistance, adhesion strength, hardness and Young's modulus changes. In addition to improving the protection against UV, the doped TiO2 and silica-coated ZnO nanoparticles in powder form have improved the abrasion resistance and barrier effect against water vapor diffusion of the acrylic stain. For most of nanocomposite coatings, the addition of ZnO hydrophilic nanoparticles in predispersed form has resulted in a decrease in WV permeability, while the adhesion strength and abrasion resistance of those coatings were negatively affected. The addition of ZnO nanoparticles has decreased the Tg of the acrylic stain. Finally, the accelerated weathering has induced an increase in Tg, hardness, Young's modulus (stiffness) and an increase in apparent adhesion strength and abrasion resistance of the coatings. The Tg values of the aged nanocomposite coatings were lower than that of unmodified acrylic stain.  相似文献   

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