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1.
Effect of TiO2 nanoparticles on the antibacterial and physical properties of polyethylene-based film
Yage Xing Xihong Li Li Zhang Qinglian Xu Zhenming Che Weili Li Yumin Bai Ke Li 《Progress in Organic Coatings》2012,73(2-3):219-224
TiO2 nanoparticles and their application in packaging systems have attracted a lot of attention because of its antimicrobial activity. In this work, effect of TiO2 nanoparticles on the antibacterial and physical properties of polyethylene (PE)-based film was investigated. Results indicated that the antibacterial activity of TiO2-incorporated PE films should be due to the killing effect property of TiO2 nanoparticles against microorganisms. The TiO2-incorporated PE film exhibited more effective antibacterial activity for Staphylococcus aureus. The antibacterial activity to inactivate Escherichia coli or S. aureus was improved by UV irradiation. The inhibition ratio of TiO2-incorporated PE films sample irradiated for 60 min by UV light was improved significantly, which were 89.3% for E. coli and 95.2% for S. aureus, respectively, compared to that of TiO2-PE film without UV irradiation. The analysis of physical properties revealed that TiO2 nanoparticles increased the tensile strength and elongation at break of PE-based film. The climate resistance of nano-TiO2 films is greatly enhanced, compared to that of the blank PE film. Water vapor transmission increased from 18.1 to 24.6 g/m2·24 h with the incorporation of TiO2 nanoparticles. Results revealed that PE based film incorporating with TiO2 nanoparticles have a good potential to be used as active food packaging system. 相似文献
2.
Polyimide/titania (PI/TiO2) nanocomposite films have been successfully fabricated through the in situ formation of TiO2 within a PI matrix via sol–gel method. Poly(amic acid) (PAA), which is the precursor of PI, was successfully synthesized by mixing pyromellitic dianhydride (PMDA), with equimolar amount of a diamine monomer having a pendent benzoxazole unit and two flexible ether linkages in N,N-dimethylformamide (DMF) solvent. Tetraethyl orthotitanate [Ti(OEt)4] and acetylacetone were then added to the resulted PAA. After imidization at high temperature, PI/TiO2 hybrid films were formed. The structure and morphology of the hybrid nanocomposites with different titania contents (0 wt%, 5 wt%, 10 wt%, and 15 wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscopy. The results indicate that the TiO2 nanoparticles were homogeneously dispersed in the hybrid films. The thermogravimetric analysis of nanocomposites confirms the improvement in the thermal stability with the increase in the percentage of titania nanoparticle. Transmission electron microscopy showed that the nanoparticles with an average diameter of 25–40 nm were dispersed in the polymer matrix. 相似文献
3.
Encapsulation of inorganic nanoparticles by polymers is one of the interesting research topics that lead to the synthesis of nanocomposites. These nanocomposite materials comprise the properties of both organic polymer and inorganic nanoparticles. Here, hybrid latex particles with core–shell nanostructure were prepared via semi-batch emulsion polymerization. Copolymers of (methyl methacrylate-butyl acrylate) and (dimethylaminoethyl methacrylate-butyl acrylate-acrylic acid) were formed as the inner and outer layers, respectively on the surface of modified TiO2 nanoparticles as the core. In order to create compatibility between inorganic and polymeric phases, modification of TiO2 nanoparticles was performed with glycidyl methacrylate with an optimized procedure for the first time and then emulsion polymerization was carried out. The products of each step were fully characterized. The results of dynamic light scattering, TEM and SEM analyses proved the formation of encapsulated hybrid latex particles. DLS and SEM data revealed that the sizes of nanocomposite particles vary between 85 and 120 nm for 0–5 wt% of the modified TiO2 nanoparticles. Physico-mechanical properties of the obtained nanocomposite films were studied by DMTA. It was found that using only 3 wt% of modified TiO2 improved those properties of resulting films remarkably. 相似文献
4.
Dye-sensitized solar cells (DSSC) derived from TiO2 aerogel film electrodes were fabricated. TiO2 aerogels were obtained by using sol–gel method and supercritical carbon dioxide (sc-CO2) drying. First, TiO2 wet gels were obtained by sol-gel method. Then, the solvents in the TiO2 wet gels were replaced by acetone. The TiO2 aerogels were obtained by using sc-CO2 drying from the TiO2 wet gels. The conditions of sc-CO2 drying were at 313, 323 K and 7.8–15.5 MPa. The electrodes with TiO2 aerogel films were obtained by deposition of the aerogels on glass substrates. The electrodes with TiO2 aerogel films and a commercial particle film of various thickness were obtained by repetitive coatings and calcinations. The amount of dye adsorbed on the TiO2 films with sc-CO2 drying was higher than that of commercial particle film. The amount of dye adsorbed on the TiO2 films increased with increasing surface area of the TiO2 film. DSSCs were assembled by using the TiO2 aerogel film electrodes and their current–voltage performance was measured. The power performance of DSSC made by supercritical drying was higher than that of commercial particles. The DSSC with the film electrode made at 313 K and 15.5 MPa showed the best power performance (Jsc = 7.30 mA/cm2, Voc = 772 mV, η = 3.28%). 相似文献
5.
Molybdenum doped TiO2 (MTO) thin films were prepared by radio frequency (RF) magnetron sputtering at room temperature and followed by a heat treatment in a reductive atmosphere containing 90% N2 and 10% H2. XRD and FESEM were employed to evaluate the microstructure of the MTO films, revealing that the addition of molybdenum enhances the crystallization and increases the grain size of TiO2 films. The optimal electrical properties of the MTO films were obtained with 3 wt% Mo doping, producing a resistivity of 1.1×10?3 Ω cm, a carrier density of 9.7×1020 cm?3 and a mobility of 5.9 cm2/Vs. The refractive index and extinction coefficient of MTO films were also measured as a function of film porosity. The optical band gap of the MTO films ranged from 3.28 to 3.36 eV, which is greater than that of the un-doped TiO2 film. This blue shift of approximately 0.14 eV was attributed to the Burstein–Moss effect. 相似文献
6.
《Ceramics International》2016,42(12):14071-14076
We modified the refractive index (n) of TiO2 by annealing at various temperatures to obtain a high figure of merit (FOM) for TiO2/Ag/TiO2 (45 nm/17 nm/45 nm) multilayer films deposited on glass substrates. Unlike the as-deposited and 300 °C-annealed TiO2 films, the 600 °C-annealed sample was crystallized in the anatase phase. The as-deposited TiO2/Ag/as-deposited TiO2 multilayer film exhibited a transmittance of 94.6% at 550 nm, whereas that of the as-deposited TiO2/Ag/600 °C-annealed TiO2 (lower) multilayer film was 96.6%. At 550 nm, n increased from 2.293 to 2.336 with increasing temperature. The carrier concentration, mobility, and sheet resistance varied with increasing annealing temperature. The samples exhibited smooth surfaces with a root-mean-square roughness of 0.37–1.09 nm. The 600 °C-annealed multilayer yielded the highest Haacke's FOM of 193.9×10−3 Ω−1. 相似文献
7.
《Ceramics International》2016,42(12):13863-13867
Anatase phase TiO2 (a-TiO2) films have been deposited on MgAl2O4(100) substrates at the substrate temperatures of 500–650 °C by the metal organic chemical vapor deposition (MOCVD) method using tetrakis-dimethylamino titanium (TDMAT) as the organometallic (OM) source. The structural analyses indicated that the TiO2 film prepared at 600 °C had the best single crystalline quality with no twins. The out-of-plane and in-plane epitaxial relationships of the film were a-TiO2(001)||MgAl2O4(100) and TiO2[100]||MgAl2O4[100], respectively. A uniform and compact surface with stoichiometric composition was also obtained for the 600 °C-deposited sample. The average transmittance of all the TiO2 films in the visible range exceeded 91% and the optical band gap of the films varied from 3.31 to 3.41 eV. 相似文献
8.
Xiangyu Cao Yasuhiro Oda Fumihide Shiraishi 《Chemical engineering journal (Lausanne, Switzerland : 1996)》2010,156(1):98-105
Anatase titanium dioxide (TiO2) in particle sizes of roughly 0.5–20 μm was prepared from amorphous TiO2 in an aqueous H2O2 solution by heating at 90 °C for 9 h and directly deposited on a PET film. On the other hand, granular activated carbon (AC) particles in sizes of 1–2 mm in diameter were adhesively deposited on a PET film, and their surfaces were also coated with TiO2. The resulting three preparations (TiO2-, AC-, and TiO2/AC-PET films) were set up in an annular-flow reactor to treat aqueous solutions of 2,4-dinitrophenol (DNP) in a batch-recirculation mode. The rate of DNP adsorption onto the TiO2/AC-PET film without UV irradiation was almost the same as that onto the AC-PET film, indicating that the attraction of DNP to AC was not lowered in the presence of TiO2 film. Observation of SEM photographs suggests that this result is attributed to the porous structure of the thin TiO2 film covering AC particles. The rate of DNP removal by the TiO2-AC PET film under UV irradiation was 2.9 times higher than that by the TiO2-PET film under UV irradiation, and was 1.1 times higher than the rate of DNP adsorption onto the AC-PET film. The rate of DNP removal by the AC-PET film decreased by 40% after six runs, while that by the TiO2/AC-PET film decreased by 22%. Durable experiments using the TiO2/AC-PET and AC-PET films clarified that the lifetime of the TiO2/AC-PET film is at least two times longer than that of the AC-PET film. This result suggests that DNP molecules are photocatalytically decomposed when passing through the porous TiO2-PET film, which lessens a burden of DNP adsorption on AC. Moreover, the DNP treatments in the batch-recirculation flow system suggested that the TiO2/AC-PET film saturated with DNP can be successfully regenerated at 60 °C. 相似文献
9.
《Ceramics International》2017,43(17):15040-15046
A process of obtaining N-doped TiO2 nanotubes sensitized by CdS nanoparticles is presented, including detailed characterizations performed along the synthesis. Transparent TiO2 films consisting of nanotubes, 2.5 µm long and of ~60 nm inner diameter, were obtained after anodization of a titanium film deposited onto FTO glass substrate. N-doping was achieved by annealing of TiO2 film in ammonia. X-ray Photoelectron Spectroscopy measurements showed that nitrogen was substitutionally incorporated in the TiO2 matrix, with the N:Ti concentration ratio of 1:100. The doping changed the optical properties of the material in such a way that the absorption edge was shifted from 380 nm to 507 nm, as observed from diffuse reflectance spectra. The influence of the microwave (MW) irradiation on the synthesized CdS quantum dots and their optical properties was investigated. It was shown that the diameter of CdS nanoparticles was increased due to releasing of S2- ions from dimethyl sulfoxide (DMSO) as a consequence of the MW treatment. The (N)TiO2 films were then used as substrates for matrix assisted pulsed laser deposition of the CdS quantum dots with DMSO as a matrix. The laser parameters for the deposition were optimized in order to preserve the nanotubular structure open, the latter being an important feature of this type of photoanode. The structure obtained under optimized conditions has an additional absorption edge shift, reaching 603 nm. 相似文献
10.
Komkrit Suttiponparnit Vinay Tiwari Manoranjan Sahu Pratim Biswas Sirikalaya Suvachittanont Tawatchai Charinpanitkul 《Journal of Industrial and Engineering Chemistry》2013,19(1):150-156
Stability of suspensions of TiO2 nanoparticles synthesized by the flame aerosol reactor (FLAR) could be altered by doping TiO2 nanoparticles with Pt, Pd, or Pt–Pd dopants. It was found that doping of TiO2 with Pd or Pt could contribute to the control of the agglomeration of TiO2 suspended in water. With the change of doping content, the isoelectric point (IEP) of stable TiO2 suspension decreased gradually from 5 to 3.6 while the specific surface area was increased from 43.27 to 60.84 m2/g. With pH > 6.0, 2 wt% Pt–Pd/TiO2 suspension exhibited the lowest agglomeration behavior. The plausible intrinsic structures of Pt, Pd, and Pt–Pd doped TiO2 nanoparticles were proposed and discussed with respect to their IEP based on the DLVO theory. 相似文献
11.
A. Kusior J. Klich-Kafel A. Trenczek-Zajac K. Swierczek M. Radecka K. Zakrzewska 《Journal of the European Ceramic Society》2013,33(12):2285-2290
Nanopowders of TiO2–SnO2 over a full composition range extending from 100 mol% TiO2 to 100 mol% SnO2 are obtained by the sol–gel method from TTIP and SnCl2·5H2O precursors of Ti and Sn, respectively followed by calcination at 400 °C. The samples are characterized by means of BET, XRD and TEM. Optical properties of the prepared nanomaterials are studied as well. TEM images indicate that the nanoparticles are regular in shape. The specific surface area, SSA of TiO2 is 95 m2/g while that of SnO2 amounts to 129 m2/g. The highest SSA of 156 m2/g is achieved at 20 mol% of TiO2. Occurrence of rutile, anatase and brookite polymorphic forms depends on the chemical composition of nanopowders. Formation of rutile-type solid solution of TiO2–SnO2 over the range of 0–80 mol% TiO2 is confirmed by Vegard rule applied to lattice constants. Electronic band gap decreases with Ti content from 3.84 eV (100 mol% SnO2) to 3.18 eV (100 mol% TiO2). 相似文献
12.
Jae-Kyung Oh Jin-Kyu Lee Sung Justin Kim Kyung-Won Park 《Journal of Industrial and Engineering Chemistry》2009,15(2):270-274
The TiO2 nanoparticles with anatase (5.7–12.7 nm), rutile (5.4–8.8 nm), mixed (4.4–8.6 nm) phase were individually prepared using the hydrothermal method. The structure and shape of the particles could be controlled by careful alterations of the hydrothermal conditions. Herein, the TiO2 nanoparticles were successfully synthesized by employing Ti-isopropoxide as the titanium source into hydrochloric acid solution at mild conditions. The crystal structures such as anatase, rutile and mixed phase of TiO2 nanoparticles were determined by means of concentration of hydrochloride. Especially, we observed that the rutile TiO2 crystallites were grown into one-dimensional nanostructures, especially, nanowires, with increasing reaction time. The mechanism of the crystallization of the nanoparticles and the growth habit of TiO2-rutile structure were discussed. 相似文献
13.
We report the application of a modified RESS process to create and collect in high yield nanoparticles of an amorphous fluoropolymer, Teflon-AF1600. The nanoparticles with diameters ranging from 10 to 100 nm can be synthesized from polymer solutions in supercritical CO2 at 300 bar and 60 °C. The nanoparticles are collected by formation of dry ice in a liquid nitrogen-cooled trap. Nanoparticles embedded in dry-ice can be dispersed in organic solvents (acetone, ethanol, and n-heptane) creating surfactant-free dispersions. When dispersed in water, the nanoparticles self-assemble at the air–water interface forming a mechanically robust, superhydrophobic film. The film can support large water droplets (up to volume 250 μL) without breaking and is impermeable to water. The films cast from dispersions as well as those lifted-off water surface, are highly porous and superhydrophobic in nature (water contact angle θadv = 162°). This work demonstrates the utility of supercritical fluids based processing of fluoropolymers. 相似文献
14.
《Ceramics International》2015,41(8):9527-9533
A TiO2(B) nanosheets/SnO2 nanoparticles composite was prepared by the hydrothermal and chemical bath deposition (CBD) methods, and its electrochemical properties were investigated for use as the anode material of a lithium-ion battery. The as-prepared composites consisted of monoclinic-phase TiO2(B) nanosheets and cassiterite structure SnO2 nanoparticles, in which SnO2 nanoparticles were uniformly decorated on the TiO2(B) nanosheets. The TiO2(B)/SnO2 composites showed a higher reversible capacity and better durability than that of the pure TiO2(B) for use as a battery anode. The composite electrodes exhibiting a high initial discharge capacity of 2239.1 mAh g−1 and a discharge capacity of more than 868.7 mAh g−1 could be maintained after 50 cycles at 0.1 C in a voltage range of 1.0–3.0 V at room temperature. The results suggest that TiO2(B) nanosheets coated with SnO2 could be suitable for use as a stable anode material for lithium-ion batteries. In addition, the coulombic efficiency of the nanosheets remains at an average of 93.1% for the 3rd–50th cycles. 相似文献
15.
SiO32? doped TiO2 films with oriented nanoneedle and nanorectangle block structure has been firstly synthesized by hydrothermal synthesis method. The prepared samples are characterized, X-ray diffraction (XRD) results demonstrate that the SiO32? doped TiO2 films are rutile and brookite phases. The scanning electron microscope (SEM) analysis reveals that the quantity of O2 affects the morphology of the SiO32? doped TiO2 films (SiTiA films prepared with unmodified substrate). The SiO32? doped TiO2 films (SiTiB films prepared with modified substrate) display two layers, one is porous structure, the other is nanoneedle structure. UV–vis, IR, transmission electron microscopy (TEM) and energy-dispersive X-ray (EDX) microscopy all prove that SiO32? have been doped in the TiO2 crystal structure. They have remarkable red shift and higher photocatalytic activity of degradation of methylene blue than P-25 under visible light (λ > 420 nm) irradiation. Besides, photocatalytic activity of the film is stable during 4 times recycling. 相似文献
16.
《Ceramics International》2017,43(11):8391-8395
Titanium dioxide (TiO2) films doped with different indium (In) concentrations have been prepared on SrTiO3 (STO) substrates by high vacuum metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD) analyses revealed the TiO2 films doped with low In concentrations to be [001] oriented anatase phase and the films with high In concentrations to present polycrystalline structures. The 1.8% In-doped TiO2 film exhibited the best electrical conductivity properties with the lowest resistivity of 8.68×10−2 Ω cm, a Hall mobility of 10.9 cm2 V−1 s−1 and a carrier concentration of 6.5×1018 cm−3. The films showed excellent transparency with average transmittances of over 85% in the visible range. 相似文献
17.
V-doped TiO2 nanoparticles were synthesized by sonochemical process using titanium isopropoxide as a titanium source, vanadyl acetylacetonate as a dopant source. Sonication was conducted using sonic horn operated at 20 kHz for 20 min until the completely precipitated product was reached. The as-synthesized precipitates with various vanadium dopant (1–5 mol %) were calcined at 500–1000 °C for 4 h. The relevant physical properties of the nanoparticles were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and transmission electron microscope (TEM). The anatase phase TiO2 nanoparticles can be synthesized by sonochemical process. Post calcinations process results in the anatase-to-rutile phase transformation and the enhancement in crystallinity with increasing temperature. The results also indicate good incorporation of V ions in TiO2 lattices and significant effect of V dopant on alternation of interplanar spacing of TiO2. 相似文献
18.
The effects of deposition temperature on orientation, surface morphology and dielectric properties of the thin films for Ba0.6Sr0.4TiO3 thin films deposited on Pt/Ti/SiO2/Si substrates by pulsed laser deposition were investigated. X-ray diffraction patterns revealed a (2 1 0) preferred orientation for all the films. With rising substrate temperature from 650 °C to 700 °C, the crystallinity and crystal grain size of the films increase, the relative dielectric constant increases, but the dielectric losses have not obvious difference. The film deposited at 350 °C and annealed at 700 °C has strongly improved roughness and dielectric permittivity compared with the film only deposited directly at 700 °C. Three distinct relaxation processes within tan(δ) were found for the BaxSr1?xTiO3 film: a broadened process of the film relaxation, an intermediate peak which originates from Maxwell–Wagner–Sillars polarization, and an extremely slow process ascribed to leak current. The complex dielectric permittivity and loss can be fitted by an improved Cole–Cole model corresponding to a stretched relaxation function. 相似文献
19.
Javad Esmaeilzadeh Sasan Ghashghaie Babak Raissi Ehsan Marzbanrad Cyrus Zamani Reza Riahifar 《Ceramics International》2012,38(7):5613-5620
The effect of dispersant on deposition mechanism of TiO2 nanoparticles at 1 Hz under non-uniform AC fields was investigated. It was found that by adding Dolapix to suspension, deposition pattern is drastically changed enabling particles to enter the gap leaving the electrodes intact. Using low frequency AC electrophoretic deposition technique in the presence of dispersant, we succeeded in fabricating gas sensor in less than 2 min. Gas sensing measurements were performed in the temperature range of 450–550 °C. The results explained that the sensor has good stability in time and repeatability performance toward high response. The maximum sensitivity of about 180 for the TiO2 nanoparticles sensor is observed with 47 ppm NO2 gas and the response and recovery times is about 60–150 s. The optimum temperature of the gas sensor was obtained in 450 °C where sensor showed a linear trend up to 50 ppm of NO2 gas. This sensing behavior in un-doped TiO2 as NO2 sensor can be mainly ascribed to the porous structure of the sensing film and its good contacts to the substrate and electrode assembly. 相似文献
20.
New transparent and high infrared reflection films having the sandwich structure of SiO2/Al:ZnO(AZO)/SiO2 were deposited on the soda-lime silicate glass at room temperature by radio frequency (R.F.) magnetron sputtering. The optical and electrical properties of SiO2 (110 nm)/AZO (860 nm)/SiO2 (110 nm) sandwich films were compared with those of single layer AZO (860 nm) films and double layer SiO2 (110 nm)/AZO (860 nm) films. The results show that these sandwich films exhibit high transmittance of over 85% in the visible light range (380–760 nm), and low reflection rate of below 4.5% in the wavelength range of 350–525 nm, which is not shown in the conventional single layer AZO (860 nm) films and double layer SiO2 (110 nm)/AZO (860 nm) films. Further these sandwich films display a low sheet resistance of 20 Ω/sq by sheet resistance formula and high infrared reflection rate of above 80% in the wavelength range of 15–25 μm. In addition, the infrared reflection property of these sandwich films is determined mainly by the AZO film. The outer SiO2 film can diminish the interference coloring and increase transparency; the inner SiO2 film improves the adhesion of the coating to the glass substrate and prevents Ca2+ and Na+ in the glass substrate from entering the AZO film. 相似文献