Advanced Materials Research Vol. 669

Abstract: Polypropylene (PP)-coated multi-walled carbon nanotubes (MWNTs) composite with MWNTs exceptional alignment dispersed and improved mechanical properties was prepared with maleic anhydride (MAH) as a compatibilizer and poly (butyl methacrylate) (PBMA) as a binding. Scanning electron microscopy (SEM) results showed that MWNTs within composite were aligned without aggregation and the oriented MWNTs were connected by matrix. High-resolution transmission electron microscopy (HRTEM) results demonstrated that the nanotubes were densely coated with a PP layer. Infrared spectroscopy (IR) results revealed that there was covalently linkage of MWNTs with PP via MAH. The interactions between MWNTs-PP and MWNTs-PBMA induced orientation of MWNTs. The improved mechanical properties of PP - coated MWNTs composite was also shown.

Abstract: The recipe of silicone glass sealant was studied, and the influence of crosslinking agent, plasticiser and reinforcing agent on its property was investigated. After compositing the glass sealant with polytetrafluoroethylene (PTFE) nanoparticles, a novel superhydrophobic silicone/PTFE glass sealant was obtained with contact angle of water more than 150o, and the effect of PTFE nanoparticles on superhydrophobicity of the nanocomposites was researched.

Abstract: A comprehensive photoprotective formulation was developed to enhance photoprotection ,compared to a conventional nanoemulsion ,having the concentration of two new molecular sunscreens, namely Diethylamino hydyoxybenzoyl hexyl benzoate(Uvinul ® A Plus) and Ethylhexyl triazone(Uvinul® T 150). In the present paper, the sunscreen mixture was incorporated into nanostructured lipid carriers (NLCs). After the production by hot high pressure homogenization, the NLC were analyzed in terms of particle size, physical state, particle shape, ultraviolet absorbance and stability. The particle size for all NLC was around 100-900 nm after production. The determination of 2 organic UV filters was performed by HPLC with UV spectrophotometric detection. The loading capacities for molecular sunscreens was up to 30%. In the sunlight, the retention rate of Uvinul ® A Plus and Uvinul ® T150 was still up to 80% after three months .

Abstract: The transparent ZnO films were deposited on the indium tin oxide (ITO) coated glass substrates by using the square wave potential deposition method. The conductive graphite plate is used for counter electrode, electrolyte consist of zinc nitrate and additive of electrochemistry, which is made up CTAB and potassium nitrate. Crystallinities of the films were examined by X-ray diffractometer. The morphologies of zinc oxide films were observed with atomic force microscope. Optical characteristics of zinc oxide layers were measured with UV–vis spectrophotometer. The optimal conditions for preparation of zinc oxide thin films with the square wave potential method were as follows: the deposition time was 6 min, concentration of zinc nitrate was 0.05mol/L, deposition temperature was 80 °C, and the annealing temperature was 500 º C. The average optical transmittance of the ZnO films is higher than 85% in the visible range. Moreover, the films have flat surface and small grain size.

Abstract: Here we demonstrate a promising gas sensor based on aniline reduced graphene oxide (RGO), which is fabricated through drop drying RGO nanosheets suspension between the electrode arrays to create conductive networks. RGO, as the sensing materials, which is prepared via the chemical reduction of graphene oxide (GO) by aniline, has been characterized by infrared spectroscopy, UV-Vis spectroscopy, transmittance electron microscopy and scanning electron microscopy. The sensing properties of RGO have also been studied, and the results show that RGO reduced from aniline (RGO-A) exhibits an excellent response to ammonia gas (NH3). Comparing with the RGO reduced from hydrazine (RGO-H) and polyaniline (PANI) nanofiber, the RGO-A exhibits a much better response to NH3 gas. The response of the sensor based on RGO-A to 50 ppm NH3 gas exhibits about 9.2 times and 3.5 times higher than those of the device based RGO-H and PANI nanofiber respectively. In addition, the RGO-A sensor exhibits an excellent repeatability and selectivity to NH3 gas. The oxidized aniline, i.e., polyaniline, which is attached on the surface of RGO sheets through π–π interaction, plays important roles in the final sensing performance of the device, and benefits for the application of the sensor in the field of NH3 gas detection.

Abstract: With polyvinyl pyrrolidone (PVP) as stabilizer and polyethylene glycol (PEG) as reducer, silver nanostructures were synthesized by microwave-assisted method. The morphology, size and crystal structure of silver (Ag) nanostructures were investigated by SEM and XRD. The results showed that the Ag nanostructures could change from nanoparticles to nanowires by introducing Cl^-. The growth speed of nanowires could be controlled by changing the reaction power, thus Ag nanorods and Ag nanowires with different length could be obtained.

Abstract: The dynamic changes of the friction properties of the oxide film are characterized by the dynamic changes of the ELID grinding force. The tangential force and normal force are used to represent the friction coefficient in order to obtain the accurate real-time friction coefficient of oxide film. Therefore, the friction coefficient of various grinding wheels with different bonding agents, various grinding parameters, various grinding materials (nano- Al2O3 ceramic, nano ZrO2 ceramic and ordinary ZrO2 ceramic), and ELID grinding and ordinary grinding can be further studied. The results show that: the friction coefficient of the oxide film on the bronze-based grinding wheel is greater than that composed by iron; the friction coefficient of the oxide film decreases with the increase in grinding depth and feeding speed; the friction coefficient of the oxide film and nano-materials is smaller than that of the oxide film and ordinary materials; the transformation from γ-Fe2O3 to α-Fe2O3 in oxide film and the elastic deformation of the oxide film caused by the high-temperature of grinding may make the friction coefficient of ELID grinding greater than that of ordinary grinding, so the oxide film contains better property of friction and polishing. Therefore, excellent surface quality is easier to be obtained by it compared with the ordinary grinding technology.

Abstract: Hexagonal and cubic mesoporous TiO₂ materials were synthesized via a sol-gel route modified by evaporation–induced self–assembly process with different templates. XRD and TEM results confirmed that the mesoporous films were highly organized. Furthermore, the hexagonal mesoporous TiO₂ films were formed in the P123-templated films, whereas the cubic structure ones were found in the F127-templated films. Both the hexagonal and cubic mesoporous films showed photocatalytic activity in decomposing methyl orange solution under UV region, among which the cubic mesostructure presented superior potocatalytic activity because of larger surface area, more open framework and less obstructed diffusion paths of guest molecules.

Abstract: Nanofibrous substrate composite ultrafiltration membrane consisted of polyacrylonitrile (PAN) electrospun scaffold which was used as the substrate, and a thin crosslinked poly(vinyl alcohol) (PVA) barrier layer which was prepared by electrospinning technique combined with mixed solvent treatment. The thickness of PVA nanofibrous top layer was controlled by changing the electrospun depositing time. Through immersing PVA/PAN double-layer mats into water/acetone mixed solvent system, the PVA nanofibrous top layer was swollen to merge imperceptibly into an integrated barrier film on the surface of PAN substrate, and then chemically crosslinked by glutaraldehyde. The resultant PVA/PAN thin film nanofibrous composite (TFNC) membrane has high rejection rate (99.6%), high flux (410.5l/m²h) and good anti-fouling characteristic at very low operation pressure (0.2MPa) for separating oil from the oilfield wastewater. Additionally, the removal of TDS, suspended matter, total iron and sulfate reducing bacteria (SRB) showed high rejection rate with relatively stable PH.

Abstract: A series of organic montomorilonite were prepared by using Sodium monanorilonite(Na-MMT) as raw material and quaternary ammonium salts with different chain long as intercalation agents by the way of ion exchange method. Weightlessness experiment showed that intercalated agents could alleviate the corrosion of metal. The MMT and organic MMT (OMMT) were identified by infrared spectra (FTIR) and X-ray diffraction (XRD). The results showed that intercalation agents had intercalated into the interlayer space of MMT, and the spacing of MMT layers had increased from 1.51 nm to 2.94 nm.