Materials Science Forum Vol. 815

Abstract: In order to study the infrared spectral characteristics of side-chain liquid crystal polymer, an infrared monomer containing a permanent dipole azobenzene group spaced from the methacryloyl moiety by a polymethylene segment was synthesized in three steps starting from 4-cyanoaniline. The monomer was polymerized with a push-pull azobenzene monomer, (-)-menthy1 methacrylate in the presence of azobisisobutyronitrile (AIBN) as the radical initiator. Structurally similar amphiphilic polymers were obtained by polymerization of analogous methacrylates in which the polymethylene spacers was replaced by oligo (oxyethy1ene) segments. The obtained polymer was characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectro photometry (UV-vis), Hot Stage Polarized Microscopy (HS-POM), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analyzer (TGA). Its infrared emissivity at different temperatures was tested by Bruker-V70 infrared analyzer. The results showed that the azobenzene poly (methyl methacrylate) (azo-PMMA) has high glass transition temperature(about 40°C), good thermal stability(divied in 294°C) and low infrared emission under 70%.

Abstract: The PtTi0.5Zr0.2/Ti laminated composite was prepared by hot pressing and rolling process. Microstructure, interlaminar spacing and mechanical property of the microlaminated composites after rolling were evaluated. The results showed that the layer structures of laminated composites remained consecutiveness with 93% deformation. The 12μm PtTi0.5Zr0.2 layer and 8μm Ti layer was observed finally, as well as the intermetallic compound Ti₃Pt making the PtTi0.5Zr0.2 layer and Ti layer connect with each other. Compared with Platinum and Titanium, the tensile strength of PtTi0.5Zr0.2/Ti laminated composite was enhanced by approximately 59% and 29% respectively and reached 657MPa. The tensile fracture was more uniform and showed a more coordinated process.

Abstract: NiO, conductive polymers have many important applications in supercapacitor, lithium-ion batteries, H₂ production with photocatalysis, chemical sensors, biosensors, electrochromic, environmental fields, and so on. Due to P-type semiconductors of NiO and polyaniline, the NiO/Polyaniline (PANi) would be a new nanocomposite with synergistic behaviors or complementary properties. Different morphologies of NiO were synthesized with hydrothermal method. NiO nanosheets arrays on glass substrate were obtained with optimized condition. And the NiO nanosheets arrays were immersed in the solution of aniline accompanying chemical oxidation reaction. The results indicated that a very thin layer of NiO, Ni (OH)₂ nanosheets arrays with organic functional modification of polyaniline were formed on glass substrate due to acid etching effects. The results of XRD showed that the presence of NiO and Ni (OH)₂ in prepared film were observed. The FTIR results also confirmed that this very thin film contained the components of polyaniline. This method is very simple, which would be used in many film electrodes for photocatalysis fields, supercapacitor, sensors, et al.

Abstract: Two kinds of Schiff bases polymers named P3TA4A and P3TA4B were prepared by the chemical oxidation method. The structures of Schiff bases polymers were determined by FT-IR and ¹H NMR. The GPC result showed that the number-average molecular weight of P3TA4A and P3TA4B was 7400 g/mol and 12500 g/mol with a molecular weight distribution of 1.63 and 1.27, respectively. The cyclic voltammetry curves showed that the energy gap of P3TA4A and P3TA4B was 1.929 eV and 1.944 eV, respectively. Ultraviolet-visible spectra and Luminescence spectra showed that the maximum absorption and maximum emission wavelength of was 275 nm, 400 nm for P3TA4A and 448 nm, 451 nm for P3TA4B. The open-circuit voltage of the polymer solar devices was 3 mv and 2.5 mv, respectively. The results indicated that the Schiff bases substituents at the 3-position of polythiophenes play an important role on the photoelectric conversion efficiency of conducting polymers.

Abstract: Smart gels have many applications in sensors, actuators, shape memory intelligent devices, recognition, self-healing, drug release, biomimetic soft robot design, biomimetic tactile, neural regeneration, biomimetic membranes, supercapacitor, dye-sensitized solar cells, advanced lithium polymer batteries, environmental fields, biomedical fields, et al. And that cyclodextrins are one of the typical macrocycles with good recognition ability, and endowed with fascinating hydrophobic cavities and hydrophilic surface, which enable the encapsulation of diverse small organic molecules by forming inclusion complexes. In this paper, grafted copolymerization between acrylic acid and N,N-dimethyl acrylamide in the presence of water-soluble cyclodextrins was carried out. The effect of ratio of copolymerization monomer on the grafted polymer was examined. The results indicated that self-crosslinking smart gel with multi-stimuli responsive was obtained by selecting suitable the ratio of copolymerization monomer, its behaviors of swelling/shrinking were examined. The adsorption properties and releasing characteristics of smart gel were performed with simulating drugs. Some meaningful results were obtained. These series grafted copolymer would also be used to modify the surface and interface properties of low-dimensional functional materials or heterostructured nanocomposites for intelligent organic-inorganic functional nanocomposites, some good results were obtained.

Abstract: Excellent performance is necessary for compressor blade when aircraft engine serves in harsh environment, where it will go through scouring from jet-stream and extraneous sand, shaking of blades and corrosion from corrosive medium, taking moisture, salt, SO₂ for example. Due to the shortage of scouring resistant and anti-corrosion property, shedding of damaged coating is a fundamental reason for the breakdown of aircraft engine blades, which is also the technique bottleneck that hinders the engineering application of compressor blades. Aiming at such problems, an amino modified epoxy coating which performed excellent scouring resistent and anti-corrosion property was fabricated on blades in this paper. Physical properties, anti-corrosion performance, abrasion resistant profiles and scouring resistant test were comprehensively evaluated. Results showed that the coating displayed a high hardness (pendulum hardness 0.9), overlong pot life, well anti-corrosion performance and excellent scouring resistant property. Pot life extends from 8h which is that of common coatings to 36h, so that it is benefit to large scale coating in engineering application. The anti-corrosion performance is similar to traditional aluminizing/inorganic silicate protect coatings, and abrasion resistant property is superior to common protect coatings. Moreover, scouring resistance performance is 3~4 times that of traditional coatings. Hence, such protective coatings could ensure the long lasting of blades protection.

Abstract: In this work, an organic double-layer protective coating (ODC) was fabricated through a simple spray process on aluminum and steel. The coating is built as double-layer structure of heat resist base layer and reflective surface layer. Laser with power 10³~10⁴ Wcm^-2 was set to ablate samples for 4s, while the temperature of panels’ back were being measured. Also, reflectivity of the coating was tested. Results demonstrated that reflectivity of ODC was up to 94%, and the panels were less apt to be ablated by laser radiation after coated, while the temperatures measured were substantially lower compared to blank panels with respect to the coating structure and composition.

Abstract: Based on the analysis of much related literature, the present article introduced some of the latest theoretical models and technologies. Meanwhile, it sums up two important issues in electrospinning development. One is that more studies will focus on melt fiber refinement and improving position accuracy. Another is orderly collection and spinning efficiency will be emphasized. This study provides a clear direction for further development of electrospinning.