Advanced Materials Research Vols. 557-559

Abstract: A porous superhydrophobic magnesium oxide coating with low sliding angle was prepared by a facile method. The water contact angle and sliding angle of the porous superhydrophobic magnesium oxide coating were 155±1.9º and 1.5º, respectively. The anti-icing property of the porous superhydrophobic magnesium oxide coating with low sliding angle was investigated in a climatic chamber with a working temperature of −6 °C. The results showed that the porous superhydrophobic magnesium oxide coating with low sliding angle can largely prevent ice formation on the surface, showing excellent anti-icing property. The porous superhydrophobic magnesium oxide coating with good anti-icing property will be perfectly desirable for outdoor equipments to reduce ice formation on their surfaces in cold seasons. This work will provide a new way to fabricate anti-icing coating and thus find applications in a variety of fields.

Abstract: Electrospinning has been attributed to be one of the most effective method to prepare nano-fibers, and widely applied in assorted fields. The nanofiber membranes made by electrospinning feature high porosity and surface area, and are qualified for vascular grafts, biological scaffolds, and wound dressings. Chitosan is non-toxic and biodegradable, making it a good biocompatible material; in addition, it is also proved to be anti-bacterial and help cell growth in wounds. This research produced nanofiber membrane with polyethylene oxide (PEO) by electrospinning; the influence of the three parameters —mixture ratio of solution, electric field, and distance between the capillary tip and the collecting plate, on electrospinning was then explored. According to the results of the experiment, electrospinning formed the optimum nanofibers when the volume mixing ratio of PEO/chitosan was 60:40.

Abstract: Abstract：(Ti, Al)N films were deposited on high-speed steel (HSS) by filtered cathodic vacuum arc (FCVA) technique under a nitrogen atmosphere. X-ray diffraction was used to characterize the structure of the films .The micro-hardness was tested. The result shows that the crystal structure and mechanical properties of (Ti,Al)N films are strongly dependent on the nitrogen partial pressure. The structure of (Ti,Al)N films is composed of Ti2N phase, TiN phase and TixAly phase. The hardness increases to a maximum at the nitrogen partial pressure of 8•0×10-2Pa, then decreases with increasing nitrogen partial pressure.

Abstract: TiO₂/SiO₂ composite films were prepared by treating the sol-gel derived films with hot water. Amorphous silica was used as a binder with the aim of producing Si-O-Ti bonds. This process was done at 90°C under atmospheric pressure, and thus anatase nanocrystals-dispersed films can be formed on various kinds of substrates including organic polymers with poor heat resistance. The formation of anatase nanocrystals was found to proceed to hydrolysis of Si-O-Ti bonds. The crystalline phase, structure, morphology and photocatalytic performance of the films have been investigated.

Abstract: This lead titanate (PbTiO₃) powder was prepared by classical hydrothermal synthesis with different TiO₂ contents at low temperature. Phase identification and crystal structure of product PbTiO₃ powders were examined by X-ray diffraction (XRD). From XRD result, hydrothermal synthesized PbTiO₃ powder was significantly formed with tetragonal symmetry. Structure morphologies of PbTiO₃ films were observed by scanning electron microscopy (SEM). Ferroelectric properties and nonvolatile memory behaviour of PbTiO₃ films were identified by means of C-V characteristics. The widths of memory window were measured to be 0.50 V and 0.56 V for PbTiO₃ film with 0.20 g and 0.22 g of TiO₂ content.

Abstract: Hot dip galvanizing is being widely used to the numerous constructional steels such as a guard rail of high way, various types of structural steel for manufacturing ship and for some other fields etc.. Recently, the cost of zinc is getting higher and higher, thus, a proper manufacturing process should be developed possibly to reduce the cost of production. one of hot dip galvanizing process, that is, flux solution immersion process is very important to control more effective coating. However, flux solution is deteriorated with increasing its using time because dissolved iron from structural steel due to continuous flux treatment was increasingly increased, which is resulted in coating badness and increment of dross. In this study, the effect of additives to elimination of iron dissolved in flux solution was investigated with four types of inner solution, that is, solution of inner barrel was filled with seawater, NaOH, thiourea, including parameters of amounts of NH₄Cl(5,10,15 and 20g) and electrolysis experiment was carried out with applied current density at 20mA/cm². For the best elimination effect of iron from flux solution, it is considered that inner barrel with separator should be filled with inner solution different from original flux solution which is involved in iron ion, and the inner solution should be composed with seawater added with additives such as NH₄Cl(10g), NaOH(0.2 g) and thiourea(0.5g) when the applied current density by electrolysis method is 20mA/cm².

Abstract: The Q235 steel sample was surface-micropored by multicomponent permeating at 923K for 2h, electroless nickel plating at 353K for 2h and sintering at 1223K for 1h. The surface morphology, microhardness distribution, mechanical property and corrosion resistance of samples were analyzed respectively by metallographic analysis, hardness test, tensile test and corrosion test. The result indicates that the surface-micropored process can enhance the surface hardness and corrosion resistance of the Q235 steel sample, while decrease its strength and plasticity at the same time.

Abstract: A novel hydrophilic and self-assemble functional methoxy polyethylene oxide propyl trimethoxysilane was synthesized by hydrosilylation reaction using methoxy polyethylene oxide monoallyl ether and trimethoxysilane. The self-assembled layer of methoxy polyethylene oxide propyl trimethoxysilane was prepared by immersing hydroxylate silicon substrate in silane solution. The structure, morphology and hydrophilicity of self-assembled layer were characterized by means of X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and water contact angle method. The results show that methoxy polyethylene oxide propyl trimethoxysilane can self-assemble on the surface of hydroxylate silicon substrate. At concentration of 0.80 g/100 mL and the self-assembling time of 60 minutes, the self-assembled layer of methoxy polyethylene oxide propyl trimethoxysilane of average molecular weight of 682 shows a brush-like structure with each brush column size of 10~15 nm in diameter and 5~8 nm in height. The correspondence of the columns height with the average length of the silane molecules suggests that the layer obtained is monolayer and the brush columns are constituted by extended PEO molecular chain units in the silane. The distribution of columns is uniform and the root-mean-square（RMS） roughness of self-assembled monolayer is 0.98 nm. Water contact angle of the monolayer is 7.4°. A super-hydrophilic surface is obtained.

Abstract: Properties of cured product which polymerizd by nopadiene and factors of curing reaction were researched. Conversion rate of the double bond was characterized and detected by FT-IR analysis, and mechanical properties of cured films were detected, too. Results showed that conversion of double bond increased firstly and then remained basically stable with the increasing of the dosage of initiators, and increased with the increase of irradiation time. Surface drying time become shorter, that is, relative curing speed become faster with the increasing of the dosage of photo-initiators and irradiation intensity, and the decreasing of the lamp distance, and conversion rates of the double bonds were 91.5 % , while illumination time 360 s in dosage of 8 % of Irgacure 6512 to the substrate were used at lamp distance 4.5 cm with 100 % irradiation intensity, respectively. The obtained UV cured coating exhibited some superior properties in flexibility, impact strength, adhesive power, hardness, acid resistance, alkali resistance, salt resistance, water resistance, and so on.

Abstract: Hybrid coatings had been prepared with water-based silicone rubber, silica sol and curing agents. This material has strong adhesion and coating properties to wood, glass, metal, ceramic, brick etc. The hybrid coatings were analyzed by atomic force microscopy (AFM). The results show that different curing agents play a key role in surface morphology of hybrid coating. Methyltris-(methylethylketoxime)silane（MOS）cured hybrid coating looks smooth and flat. When the concentration of curing agent was 3.0 wt%, the surface roughness of 20 wt% silica sol hybrid coating was only 47.2 nm. At the same conditions, 3-triethoxysilylpropylamine (APTES) cured hybrid coating displays cluster structure and the surface roughness of hybrid coating could reach 368 nm in height. With the increase of the concentration of APTES, the cluster structure becomes more obvious and the surface roughness also increases gradually. When the concentration of silica sol is increased from 15 to 30 wt%, with 3.0 wt% APTES as curing agent, the surface roughness of the hybrid coating increases from 312 to 511 nm, respectively.