稀土β成核剂改性PPR力学与结晶性能研究

研究了稀土β成核(剂WBG-1改)性无规共聚聚丙烯(PPR的)力学行为,并利用热台偏光显微镜和广角X射线衍射观察和分析了WBG-1改性PPR的晶型和结晶形态。结果表明:随着WBG-1用量的增加,PPR的拉伸强度、弯曲强度和弯曲模量呈现先降后升趋势,而其冲击强度和断裂伸长率呈现先升后降的趋势,且在WBG-1用量为0.3%时均达到最大值;添加WBG-1后改,性PPR的β晶含量和结晶速度明显提高。     

玻璃窑炉烟气脱硝脱硫除尘一体化技术

针对玻璃窑炉烟气特性和排放情况以及脱硝脱硫除尘一体化技术进行了介绍,并通过实际案例分析,对玻璃窑炉的烟气处理提出了针对性的一体化解决方案。     

A novel electric elastomer based on starch/transformer oil drop/silicone rubber hybrid

The electrorheological fluid composed of starch particles and silicone oil/transformer oil was dispersed into 107 silicone rubber, and then two types of electric elastomers were prepared in the absence and presence of a curing electric field, respectively. The storage modules were measured using dynamic mechanical analysis with the round disk compression clamp. The results indicate that the storage modulus sensitivity of electric elastomers composed of pure transformer oil is the highest, that of electric elastomers composed of pure silicone oil takes second place, and that of electric elastomers composed of mixture oil is the smallest. For the given starch concentration, the storage modulus sensitivity attains a maximum value of 3.88 when the mass ratio between the transformer oil and 107 silicone rubber is 1. For the given mass ratio of 1, the effects of starch concentration and the presence or absence of the curing electric field on the storage modulus of electric elastomers were studied. When the starch concentration is 5 wt %, the storage modulus of the elastomer without the electric field (denoted as A‐elastomer) is 20.1 kPa, whereas that of the elastomer with the electric field (denoted as B‐elastomer) is 101.8 kPa. The storage modulus sensitivity attains a maximum value of 4.07. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis and photovoltaic properties of dithienyl benzotriazole based poly(phenylene vinylene)s

Two new alternating copolymers based on dithienyl benzotriazole segment and phenylene vinyl unit were synthesized by Heck cross coupling method. The polymers exhibited broad absorption bands (from 300 nm to 752 nm for P1 , and from 300 nm to 654 nm for P2 ) in the UV‐visible region with optical bandgap ranging between 1.6 and 1.9 eV and proper electronic energy levels measured by cyclic voltammetry. The photovoltaic properties of the polymers as electron donors with 6.6‐phenyl C61‐butyric acid methyl ester as the electron acceptor in a bulk heterojunction structures were reported. Preliminary results showed moderate power conversion efficiency of 0.36% and 0.4%, respectively, under the illumination of AM 1.5, 100 mW/cm² with a device structure of ITO/PEDOT : PSS/polymer : PC₆₀BM (1 : 3)/Ca/Al. Furthermore, the side chain effect on properties has also been investigated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Encapsulation of disperse dye by phase separation technique using poly(styrene‐maleic acid)

C.I. disperse dye blue 60 was encapsulated by poly(styrene‐maleic acid) using phase separation technique, followed by the preparation of the encapsulated disperse dye dispersion. The effects of process conditions on particle size of the dispersion were investigated. The results showed that the particle size of the encapsulated disperse dye dispersion was small, and the stability was excellent when mass ratio of poly(styrene‐maleic acid) to disperse dye (R_p/d), dropping speed of phase separation agent (D_s), disperse dye content in dispersion (C_d), and dispersing time (D_t) were about 20%, 7 mL/min, 5–7.5%, and 1.5 h, respectively. Transmission electron microscope (TEM), zeta potentials, and contact angle indicated that C.I. disperse dye blue 60 was successfully encapsulated by poly(styrene‐maleic acid). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cost‐effective porous ceramic tubes fabricated through a phase inversion/casting process using calcined bauxite

Cost‐effective ceramic tubes based on low‐price commercial calcined bauxite for economical separation were fabricated by a new phase‐inversion casting method. The thermal shrinkage and weight loss during heating of the green tubes were characterized by dilatometric analysis and TG, respectively. Three shrinkage stages appear successively, corresponding to the viscous deformation of polymeric binder at 200‐300°C, significant combustion loss of ~5.2 wt% at 500‐620°C and sintering shrinkage over 800°C, respectively. However, due to high enough viscosity of the casting suspension that can guarantee the green tube against collapse or deformation during the phase inversion/casting process, the sintered tubes display nearly uniform microstructure instead of characteristic asymmetrical structure of the phase inversion process. The influence of sintering temperature on the pore property (including pore size and porosity) and mechanical strength was investigated. As the sintering temperature increases from 1200 to 1400°C, the porosity and average pore size decrease from 46.4% to 37.0% and from 0.98 to 0.81 μm, respectively, and the flexural strength increases from 25.8 to 65.1 MPa. The cost‐effective ceramic tube sintering at the range of 1250‐1400°C can be capable of functioning as a microfiltration membrane or an ultrafiltration membrane support.     

Effects of microstructure on electrochemical reactivity and conductivity in nanostructured ceria thin films

The proton conductivity in functional oxides is crucial in determining electrochemistry and transport phenomena in a number of applications such as catalytic devices and fuel cells. However, single characterization techniques are usually limited in detecting the ionic dynamics at the full range of environmental conditions. In this report, we probe and uncover the links between the microstructure of nanostructured ceria (NC) and parameters that govern its electrochemical reaction and proton transport, by coupling experimental data obtained with time‐resolved Kelvin probe force microscopy (tr‐KPFM), electrochemical impedance spectroscopy (EIS), and finite element analysis. It is found that surface morphology determines the water splitting rate and proton conductivity at 25°C and wet conditions, when protons are mainly generated and transported within surface physisorbed water layers. However, at higher temperature (i.e., ≥125°C) and dry conditions, when physisorbed water evaporates, grain size, and crystallographic orientation become significant factors. Specifically, the proton generation rate is negatively correlated with the grain size, whereas proton diffusivity is facilitated by surface {111} planes and additional conduction pathways offered by cracks and open pores connected to the surface.     

Non‐isothermal crystallization kinetics of Al2O3‐YAG amorphous ceramic coating deposited via plasma spraying

Crystallization kinetics of the newly developed Al₂O₃‐Y₃Al₅O₁₂ (YAG) amorphous ceramic coating fabricated by atmospheric plasma spraying (APS) were investigated via differential scanning calorimetry (DSC) under non‐isothermal conditions. The phase compositions and microstructure of the as‐sprayed coating were characterized by X‐ray diffraction (XRD) and Scanning electron microscopy (SEM). The glass transition temperature T_g, the onset temperature of crystallization T_c and the peak temperature of crystallization T_p presented heating rate dependence. The related kinetic parameters of activation energies (E_g, E_c, E_p) and Avrami exponents (n) were quantified using various methods including Kissinger, Augis–Bennett, Ozawa and Matusita–Sakka, etc., to understand the phase transition mechanism and crystallization process in depth. A series of parameters including devitrification interval ΔT, thermal stability (T_c, E_c), nucleation resistance E_c/RT_g and fragility index F were quantified in order to evaluate the nucleation mechanism, crystallization behavior and thermal stability of Al₂O₃‐YAG amorphous ceramic coating. Excellent thermal stability was witnessed in the studied coating. Furthermore, the YAG crystalline phases can be reasonably controlled and independently precipitated from the amorphous matrix via proper annealing.