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1.
Tuncay Tun? ?brahim Uslu ?enol Durmu?o?lu Selda Keskin Arda Aytimur Ahmet Akdemir 《Journal of Inorganic and Organometallic Polymers and Materials》2012,22(1):105-111
In this study, boron doped and undoped poly (vinyl) alcohol/bismuth–gadolina acetate (PVA/Bi–Gd) nanofibers were prepared
using electrospinning technique then calcinated at 800 °C for 2 h. The originality of this study is the addition of boron
to metal acetates. The effects of boron doping were investigated in terms of solution properties, morphological changes and
thermal characteristics. The characteristics of the fibers were investigated with FT-IR, XRD, SEM and BET. The addition of
boron did not only increase the thermal stability of the fibers, but also their diameters, which yielded stronger fibers.
XRD analyses showed that boron doping increased the peak intensities and indicated that the boron doping enhanced the crystallite
size. Moreover, no shifts were noticed in diffraction angles for boron doped and undoped samples. Therefore, boron doping
did not significantly alter the lattice spacing. The SEM micrograph of the fibers showed that the addition of boron resulted
in the formation of cross-linked bright-surfaced fibers. The average fiber diameter for boron doped and undoped fiber mats
were 204 and 123 nm, respectively. Also, grain diameters of boron doped and undoped nanocrystalline sintered powders were
measured as 140 and 118 nm, respectively. The BET results showed that boron undoped and doped Bi2O3–La2O3 nanocrystalline powder ceramic structures sintered at 800 °C have surface areas of 59.72 and 39.80 m2/g, respectively. 相似文献
2.
Şenol Durmuşoğlu İbrahim Uslu Tuncay Tunç Selda Keskin Arda Aytimur Ahmet Akdemir 《Journal of Polymer Research》2011,18(6):1999-2004
Boron doped poly(vinyl) alcohol/ bismuth - lanthanum acetate (PVA/Bi-La) nanofibers were prepared by electrospinning using
PVA as a precursor. The effect of boron doping was investigated in terms of solution properties, morphological changes and
thermal characteristics. The fibers were characterized by FT-IR, XRD, SEM and BET. The addition of boron did not only increase
the thermal stability of the fibers, but also their diameters, which yielded stronger fibers. XRD analyses showed that boron
doping increased the peak intensities and indicated that the boron doping enhanced the crystallite size. Moreover, no shifts
were noticed in diffraction angles for boron doped and undoped samples. Therefore, boron doping did not significantly alter
the lattice spacing. The SEM micrograph of the fibers showed that the addition of boron resulted in the formation of cross
linked bright surfaced fibers. Also, grain diameters of boron doped and undoped nanocrystalline sintered powders were measured
as 170 nm and 120 nm respectively. The BET results show that boron undoped and doped Bi2O3-La2O3 nanocrystalline powder ceramic structures sintered at 800 °C have surface areas of 20.44 m2/g and 12.93 m2/g, respectively. 相似文献
3.
《Journal of Industrial and Engineering Chemistry》2014,20(4):1421-1431
CuO was incorporated into nano-particles of clinoptilolite via ion exchange and calcination processes. The obtained composite (CuO-NCP) was used for the photodeclorization process of an aqueous mixture of Methylene Blue and Bromophenol Blue. All samples were characterized by FT-IR, XRD, DRS, SEM and SEM. The optimum conditions were approximated as: 7 ppm dyes, pH 5.9, catalyst dose of 0.2 g L−1 and CuO loading of 4.9%. The declorization extents of 61% and 32% were respectively obtained for MB and BPB during 180 min irradiation. The degradation extent was monitored by UV–vis spectroscopy and confirmed by chemical oxygen demand (COD). 相似文献
4.
M. Eid M. B. El-Arnaouty M. Salah El-Sayed Soliman El-Sayed A. Hegazy 《Journal of Polymer Research》2012,19(3):9835
A series of PVA/PVP based hydrogels at different compositions were prepared by gamma irradiation. The gel fraction degree
of swelling were investigated. Highly stable and uniformly distributed silver nanoparticles have been obtained onto hydrogel
networks. The morphology and structure of (PVA/PVP) hydrogel and dispersion of the silver nanoparticles in the polymeric matrix
were examined by scanning electron microscopy (SEM) and infrared spectroscopy (FT-IR), respectively. The formation of silver
nanoparticles has been confirmed by ultraviolet visible (UV–vis) spectroscopy. A strong characteristic absorption peak was
found to be around 420 nm for the silver nanoparticles in the hydrogel nanocomposite. The X-ray diffraction pattern confirmed
the formation of silver nanoparticles with average particle size of 12 nm. The diameter distribution of silver nanoparticles
was determined by dynamic light scattering DLS. Transmission electron microscope (TEM) showed almost spherical and uniform
distribution of silver nanoparticles through the hydrogel network and the mean size of silver nanoparticles ranging is 23 nm.
The good swelling properties and antibacterial of PVA/PVP-Ag hydrogel suggest that it can be a good candidate as wound dressing. 相似文献
5.
Poly(vinyl alcohol) (PVA) nanofiber mats were collected on indium tin oxide (ITO) substrate by electrospinning method. A multilayer film composed of α-[P2W18O62]6− (abbr. P2W18), a polyoxometallate (POM) anion, and poly(diallymethylammonium chloride) (abbr. PDDA) was fabricated by layer-by-layer (LBL) self-assembly technique on the PVA/ITO electrode. The PDDA/P2W18 multilayer film could be unselectively or selectively deposited on the PVA/ITO electrode via changing the amount of PVA nanofibers on the ITO substrate. The scanning electron microscope (SEM) images showed that when the electrospun time was short the PDDA/P2W18 multilayer film was unselectively deposited on PVA nanofiber mats because the amount of PVA nanofibers was too little to cover most of the ITO substrate. However, when the electrospun time was long enough, the PDDA/P2W18 multilayer film was selectively deposited on PVA nanofiber mats because of the larger surface area and higher surface energy of PVA nanofibers in comparison with the flat ITO substrate. Growth process of the multilayer film was determined by cyclic voltammetry (CV). Electrocatalytic effects of the PDDA/P2W18 multilayer film unselectively and selectively deposited on the PVA/ITO electrode on NO2− were observed. 相似文献
6.
《Journal of Industrial and Engineering Chemistry》2014,20(6):4415-4420
Poly(vinyl alcohol) (PVA)/chitosan (CS)/graphene oxide (GO) biocomposite nanofibers have been successfully prepared using aqueous solution by electrospinning. CS colloidal gel in 1% acetic acid can be changed to homogeneous solution by using electron beam irradiation (EBI). The uniform distributions of GO sheets in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and Raman spectroscopy. FESEM images illustrated that the spread single GO sheet embedding into nanofibers was formed via self-assembly of GO sheet and PVA/CS chains. And the average diameters of the biocomposite nanofibers decreased (200, 173, 160 and 123 nm) with increasing the contents of GO (0.05, 0.2, 0.4 and 0.6 wt%). Raman spectra verified the presence of GO in the biocomposite nanofibrous mats. The mechanical properties of as-prepared materials related with GO contents. It revealed that the highest tensile strength was 2.78 MPa, which was 25% higher than that of neat PVA/CS nanofibers. Antibacterial test demonstrated that the addition of GO to PVA/CS nanofiber had great ability to increase inhibition zone till 8.6 mm. Overall, these features of PVA/CS/GO nanofibers which were prepared by eco-friendly solvent can be a promising candidate material in tissue engineering, wound healing and drug delivery system. 相似文献
7.
A high yield of graphene oxide (GO) was chemically synthesized from graphite powder utilizing adjusted Hummer's method. The contents of acidic functional groups in GO were determined using potentiometric titration. Composite hydrogels dependent on graphene oxide/poly(2-acrylamido-2-methylpropanesulfonic acid)/polyvinyl alcohol (GO/PAMPS/PVA) were synthesized utilizing a 60Co gamma irradiation source at different doses. The synthesized graphene oxide and composite hydrogels were portrayed via X-ray diffraction, thermogravimetric analysis, and Fourier transform infrared analysis. The morphology of composite hydrogels was characterized by scanning electron microscope. The gel % and swelling % for the prepared hydrogel demonstrated that the swelling % of hydrogel increased with raising AMPS content. Whereas the increment of GO and increasing the irradiation dose lead to a reduction in the swelling %. The influences of pH, GO percentage, initial dye concentration, the adsorbent dosage, contact time, and temperature on the adsorption of basic blue 3 dye were evaluated and the adsorption capacity was 194.6 mg/g at optimum conditions; pH = 6, GO/PAMPS/PVA composite hydrogels with 5 wt% of GO, initial dye concentration = 200 mg/L, adsorbent dose = 0.1 g, solution volume = 50 mL after 360 min at room temperature (25°C). The adsorption of dye onto the GO/PAMPS/PVA composite hydrogels follows Pseudo-second-order adsorption kinetics, fits the Freundlich adsorption isotherm model. 相似文献
8.
Polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) hydrogel has been prepared by using γ-irradiation technique. In the present
study the conclusion on miscibility of PVA/PVP blends, confirmed qualitatively and quantitatively by using Fourier transform
infrared spectroscopy and differential scanning calorimetry, respectively. PVA and PVP are found to form a thermodynamically
miscible pair. The physical properties such as gel fraction and water absorption performance of the prepared hydrogels were
measured, it was found that the gel fraction increases with increasing irradiation dose while the swelling of PVA/PVP blended
hydrogels nearly tends to increase with increasing PVP content and reduced with enhanced irradiation doses. The hydrogel pore
structure of various PVA/PVP compositions were tested with SEM. Ability of PVA/PVP hydrogels to absorb and release antimicrobial
compounds was tested using amoxicillin as an antibacterial and ketoconazole as an antifungal. Antimicrobial activity of PVA/PVP
hydrogels was examined using four bacteria, and four fungi. No antibacterial or antifungal activities of non-loaded PVA/PVP
of various compositions were detected while the loading ones found to have antimicrobial activity. Results showed resistance
of Pseudomonas aeruginosa and Candida albicans to PVA/PVP, while Bacillus subtilis was very sensitive. Biodegradation of PVA/PVP hydrogels was investigated by burial method in two types of local soils (clay
and sandy soils). The highest degradation rate was found to be achieved using clay soil. Also, effect of irradiation dose
on its biodegradability was tested. The results showed that the radiation prepared PVA/PVP hydrogels can be use as biomaterials. 相似文献
9.
Preparation of a PVA/HAP composite polymer membrane for a direct ethanol fuel cell (DEFC) 总被引:2,自引:0,他引:2
Chun-Chen Yang Ying-Jeng Lee Shwu-Jer Chiu Kuo-Tong Lee Wen-Chen Chien Che-Tseng Lin Ching-An Huang 《Journal of Applied Electrochemistry》2008,38(10):1329-1337
A novel PVA/Hydroxyapatite (HAP) composite polymer membrane was prepared by the direct blend process and solution casting
method. The characteristic properties of the PVA/HAP composite polymer membranes were investigated using thermal gravimetric
analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), micro-Raman spectroscopy and the AC impedance
method. An alkaline direct ethanol fuel cell, consisting of an air cathode with MnO2 carbon inks based on Ni-foam, an anode with PtRu black on Ni-foam, and the PVA/HAP composite polymer membrane, was assembled
and investigated. It was found that the alkaline direct ethanol fuel cell comprising of a novel cheap PVA/HAP composite polymer
membrane showed an improved electrochemical performance in ambient temperature and air. As a result, the maximum power density
of the alkaline DEFC, using a PtRu anode based on Ni-foam (10.74 mW cm−2), is higher than that of DEFC using an E-TEK PtRu anode based on carbon (7.56 mW cm−2) in an 8M KOH + 2M C2H5OH solution at ambient temperature and air. These PVA/HAP composite polymer membranes are a potential candidate for alkaline
DEFC applications. 相似文献
10.
The polyaniline (PANI)/activated carbon (AC) nanocomposite electrodes were prepared by electropolymerization of aniline monomers on the surface of AC/polyvinyl alcohol (PVA) electrodes for supercapacitor studies. Fourier transforms infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses were performed to characterize the structure and morphology of the nanocomposite electrodes. The electrochemical properties of the prepared nanocomposite electrodes and the supercapacitive behavior of the PANI, AC, and AC/PANI/PVA electrodes were investigated using cyclic voltammetry (CV) and galvanostatic charge/discharge measurements, respectively. Morphological studies showed that a thin film of PANI has been uniformly deposited on the porous surface of AC electrode, and an ordered arrangement of nanostructures with interlinked porous network has been made. Electrochemical measurements showed that AC particles prevent the degradation of PANI chains during charge/discharge cycles. The specific capacitance of the AC/PANI/PVA nanocomposite electrode was 338.15 F/g which is higher than that of the pristine AC electrode (0.08 F/g). This is due to the contribution of PANI chains by their pseudocapacitance (redox reaction) properties. Although the specific capacitance of PANI electrode (378.57 F/g) was greater than that of the nanocomposite electrode, the cyclic stability of the PANI electrode was lower than that of the AC/PANI/PVA nanocomposite electrode. 相似文献
11.
A water-soluble organic-inorganic hybrid material based on polyhedral oligomeric silsesquioxane and polyvinyl alcohol 总被引:1,自引:1,他引:0
Xiaojing Zhang Chunmian Yan Shaoming Fang Chenggui Zhang Tiangang Jia Yi Zhang 《Journal of Polymer Research》2010,17(5):631-638
A novel series of organic-inorganic hybrid materials involving cage-like octa(3-chloroammoniumpropyl)silsesquioxane and Polyvinyl
alcohol (OCAPS/PVA) were prepared via solution blending method. The obtained hybrid films were optically transparent and soluble
in water. OCAPS/PVA hybrids were characterized by FT-IR, wide-angle X-ray diffraction (WAXD) scanning electronic microscopy
(SEM), energy dispersive X-ray spectroscopy (EDS), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA)
and tensile test. The results showed that the hydrogen bond interactions were formed between OCAPS and PVA. OCAPS could be
dispersed well in PVA matrix till its content was 10 wt%, while the aggregation and crystallization of OCAPS were observed
when the content was up to 15 wt%. The glass transition temperature (T
g
) of OCAPS/PVA was found to increase from 53 °C to 60 °C, and the melting temperature (T
m
) decreased from 180 °C to 171 °C with increasing OCAPS content from 0 wt% to 15 wt%. The thermal stability of PVA main chain
was improved by the addition of OCAPS and the thermal residue ratio also increased. The tensile strength of OCAPS/PVA decreased
from 28 MPa to 19 MPa, while the elongation at break of hybrid films increased from 121% to 175%. 相似文献
12.
Fabrication of blend biodegradable nanofibrous nonwoven mats via multi-jet electrospinning 总被引:1,自引:0,他引:1
A series of blend biodegradable nanofibrous mats comprising poly(vinyl alcohol) (PVA) and cellulose acetate (CA) were prepared via multi-jet electrospinning. A relative high voltage (20 kV) was used to supply the power for multi-jet electrospinning. The weight ratio of PVA/CA in blend nanofibrous mats can be controlled by changing the number ratio of jets of PVA/CA. Moreover, the real composition of PVA and CA in blend nanofibrous mats was determined by immersing the blend nanofibrous mats into water to remove the PVA component. Morphology, dispersibility, and mechanical properties of blend nanofibrous mats were examined by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR) spectroscopy, wide-angle X-ray diffraction (WAXD), and tensile test. The results showed that the blend nanofibrous mats have good dispersibility. Additionally, the mechanical properties of blend nanofibrous mats were largely influenced by the weight ratio of PVA/CA in blends. Potential applications of the blend nanofibrous mats include filters and biomedical materials. 相似文献
13.
M. K. Manjula K. M. Lokanatha Rai J. M. Raj C. S. Manjula Siddaramaiah C. Ranganathaiah 《Journal of Polymer Research》2010,17(1):89-98
Blends of poly (vinyl alcohol) (PVA), poly-N-acyl ethyleneimine (PEI) and gelatin (PVA/ PEI/Gel) in the weight ratios 100/0/2,
95/5/2, 90/10/2, 85/15/2, 80/20/2 and 70/30/2 were prepared by solution casting method. The effects of poly (ethylene imine)
component in the blend and microwave irradiation on the mechanical and microstructural properties have been investigated using
various techniques along with Positron Annihilation Lifetime Spectroscopy (PALS). We observed tremendous improvement in mechanical
properties after microwave irradiation for 60 s in 5 wt% of PEI component blend. These results are supported by the SEM data
as well the optical data. The free volume data from positron results showed minimum free volume at 5 wt% of PEI after 60 s
of irradiation due to cross linking through hydrogen bond formation and possible estrification among the blend components.
These results correlate well the mechanical properties like tensile strength and modulus. 相似文献
14.
Rodrigo Ferreira Gouvêa Willian Hermogenes Ferreira Loan Filipi Calheiros Souto Raquel Pires Gonçalves Bluma Guenther Soares Cristina Tristão Andrade 《应用聚合物科学杂志》2021,138(40):51186
Biocompatible materials with high dielectric constant and low dielectric loss have applications in bio-related electronic devices. Development of flexible materials with those properties is still a challenge. In this work, electrospun membranes and films are prepared from poly(vinyl alcohol) (PVA) and chitosan (CS) solutions, incorporated with a reduced graphene oxide-zinc oxide composite (rGO-ZnO). Blending CS with flexible PVA favors electrospinnability and mechanical properties. ZnO contributes to hinder agglomeration of conductive rGO sheets. The structural, mechanical, dielectric and electrical properties of the hybrid materials are investigated. Infrared spectroscopy reveals interaction between the filler and the polymeric components. For mats and films, the increase in rGO-ZnO content leads to lower crystallinity. The Young's modulus and stress at break values increase with increasing rGO-ZnO content. High dielectric constants (ε' = 132 to ε' = 166, at 103 Hz), associated with low dielectric loss factor (tan δ = 0.02), are determined for the PVA/CS/rGO-ZnO films. 相似文献
15.
Chitosan was extracted from the fungus Aspergillus niger, an alternative source of chitin that is widely available as a byproduct of the industrial production of citric acid. Chitosan with deacetylation degree (DD) of 73.6% was characterized by elemental analysis, capillary viscometry (molecular weight of 1.9 × 105 g/mol), Fourier transform infrared (FTIR), nuclear magnetic resonance (1H NMR, 13C NMR and 15N NMR) spectroscopies, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Fungal chitosan was crosslinked with glutaraldehyde and glutaric acid to obtain hydrogels. Chitosan hydrogels were characterized by FTIR and by scanning electron microscopy (SEM), which showed that these materials have irregular, polydisperse, and interconnected pores. Kinetic studies of the release of betahistine from the swollen hydrogels showed a Fickian diffusion mechanism. Finally, hydrolytic degradation of chitosan hydrogels under simulated physiological conditions (pH 7.4 and 37 °C) was investigated as well as in vivo biocompatibility tests using New Zealand white rabbits as animal models. 相似文献
16.
Qinghuan Zeng Jinmin Qin Xueqiong Yin Haifang Liu Li Zhu Wenyuan Dong Song Zhang 《应用聚合物科学杂志》2016,133(26)
Chitosan was deacetylated and carboxymethylated to prepare O‐carboxymethyl chitosan (CMC) for further electrospinning. CMC was characterized using FTIR, NMR, and chemical titration, indicating a degree of carboxymethylation of 51.4%. CMC was electrospun together with poly(vinyl alcohol) (PVA) to prepare membranes composed of nanofibers. The electrospinning conditions were optimized. The CMC/PVA membrane obtained at the conditions of 15.2 g/mL CMC 50 mL, 8 g/mL PVA 5 mL, 25 kV, and a distance of 23 cm, had nanofibers without beads, with diameters of 70–200 nm. The mats were crosslinked by glutaraldehyde before platelet adhesion measurement. The nanofibrous structure remained after crosslinking while the wettability decreased. CMC/PVA mats with higher CMC amount and fewer beads, had fewer adherent platelets and less platelets aggregation showing better hemocompatibility. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43565. 相似文献
17.
《Journal of Industrial and Engineering Chemistry》2014,20(4):1656-1664
Sorption of Cd(II), Ni(II) and U(VI) ions onto a novel cast PVA/TiO2/APTES nanohybrid adsorbent with variations in adsorbent dose, pH, contact time, initial metal concentration and temperature has been investigated. The adsorbent were characterized by SEM and FTIR analysis. BET surface area, pore diameter and pore volume of adsorbent were 35.98 m2 g−1, 3.08 nm and 0.059 cm3 g−1, respectively. The kinetic and equilibrium data were accurately described by the double-exponential and Freundlich models for all metals. The maximum sorption capacities were 49.0, 13.1 and 36.1 mg g−1 for Cd(II), Ni(II) and U(VI) ions with pH of 5.5, 5 and 4.5, respectively. Thermodynamic studies showed that the sorption process was favored at higher temperature. The adsorbent can be easily regenerated after 5 cycles of sorption–desorption. 相似文献
18.
Zakaria I. Ali Omayma Ebraheem Hoda H. Saleh Fatma H. Abd Salam Rehab Sokary 《Polymer Engineering and Science》2015,55(11):2583-2590
Films of poly(vinyl alcohol)/cadmium sulphide (PVA/CdS) nanocomposite containing various concentrations of Cd2+ ions were prepared using gamma radiation at different doses from 50 up to 200 kGy. The UV/VIS spectra revealed that the CdS/PVA nanocomposites showed blue shift for the absorption peak as compared with bulk CdS. As the irradiation dose increased, a gradual red shift in the wavelength accompanying with broadening of the absorption peak was observed. The estimated optical band gap energies and the calculated CdS particle sizes of (PVA/CdS) showed correlation between their values and the variable parameters (irradiation dose and Cd+2:S?2 molar ratio). Transmission electron microscopy images showed that the CdS/PVA nanocomposites were dispersed as spherical CdS nanoparticles with homogeneity at either lower concentration of CdCl2 or irradiation dose. The nano‐rod structures of CdS was accompanied with small agglomeration at either higher CdCl2 concentration or irradiation dose. A cubic phase and mixture of cubic and hexagonal phases of the prepared CdS nanoparticles were formed at lower and higher CdCl2 concentrations, respectively. Fourier Transform Infrared spectra confirmed the coordination of CdS nanoparticles with the hydroxyl groups of PVA matrix. POLYM. ENG. SCI., 55:2583–2590, 2015. © 2015 Society of Plastics Engineers 相似文献
19.
Yu-Xuan Li Ping Li Yu-Zhe Wu Zhen-Liang Xu Ming-Ling Huang 《Ceramics International》2021,47(2):2180-2186
A novel TiO2 thin film was prepared on the ceramic hollow fiber by the sol-gel method using poly(vinylpyrrolidone) (PVP) and polyvinyl alcohol (PVA) as additives. SEM images verified the formation of TiO2 layer with various thickness using different composition of titania sols. The effect of the PVP and PVA contents on the TiO2 sol properties, the separation and the antifouling performance of the ultrafiltration membranes were investigated thoroughly. When the contents of PVP and PVA were 1.0 wt% and 0.8 wt%, respectively, the resultant membrane showed a thickness of 0.55 μm with a pure water flux of 255 L m?2 h?1. In addition, the adherent foulant bovine serum albumin was applied to evaluate the antifouling performance. During the three fouling-recovery cycles, the flux recovery ratio and the flux decay ratio maintained about 99% and 30%. The BSA flux and rejection were still 169 L m?2 h?1 and 96.9% after the cycles, indicating a superior antifouling property. 相似文献
20.
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