PE抗菌食品保鲜膜的研制

先将抗菌粉体制成抗菌母料，然后将抗菌母料按一定比例添加至聚乙烯原材料中，通过混匀、吹塑等工艺制备了抗菌食品保鲜膜。研究了该抗菌食品保鲜膜的抗菌性能、物理机械性能、光老化性能和卫生理化性能。发现当抗菌母料的添加量为4％时，抗菌食品保鲜膜具有抗菌效果好、抗菌谱广等特点；而它的物理机械性能没有明显变化，光老化性能良好，且卫生理化性能均符合要求。     

Formulation effects on the distribution of pigment particles in paints

Modern water-borne paints are widely used in different areas of applications ranging from high-gloss lacquers to flat, scrub-resistant interior paints. From this point of view, the pigment volume concentration (PVC) is one key-parameter adjusting the desired application properties. In high-gloss paints, for example, a low PVC is required to accommodate the proper surface roughness to achieve a high gloss. Consequently, a high concentration of TiO₂ is needed to obtain a good hiding power at the same time. Flat paints nonetheless are highly filled due to cost reasons preferentially by CaCO₃ and the pigment binding capacity of the binder is crucial. In this work, paint formulations differing in PVC, and the type of binder or dispersing agent were investigated by various techniques concerning the distribution and aggregation of pigment particles, e.g. TiO₂. To get a detailed insight into the structure of the liquid paints and the corresponding dried paint films, suitable analytical tools were applied for characterization. The structure of the liquid paints was analyzed by remission light spectroscopy (RLS), disc centrifugation, cryogenic-replication transmission electron microscopy (Cryo-replica TEM) and cryogenic-scanning electron microscopy (Cryo-SEM). The pigment distribution in the corresponding dried paint films was examined by means of atomic force microscopy (AFM), TEM and RLS. The tendency of the TiO₂-pigments to form aggregates was found to depend on both: first on the type of binder used in the formulation and second on the employed dispersing agent. It is shown that only by adjusting the properties of the binder in combination with common dispersants, it is possible to get well-distributed TiO₂ particles within the paint. Correlation of application properties, e.g. gloss and blocking to the microscopic structure is presented.     

陶瓷溅射靶材的发展与应用

在信息产业不少基础产品的制造过程中需使用多种陶瓷溅射靶材，世界陶瓷靶材的市场销售规模日益扩大。本文简要介绍了陶瓷靶材的应用分类、性能要求、制备工艺及溅射靶材制造中急需解决的主要技术问题。     

Organic thin film transistors: Materials,processes and devices

For the past ten years, organic materials have been extensively investigated as an electronic material for thin film transistor (TFT) devices. Organic materials offer strong promise in terms of properties, processing and cost effectiveness and they can be used in flat panel displays, imagers, smart cards, inventory tags and large area electronic applications. In this review, we summarize the current status of the organic thin film transistors including substrate materials, electrodes, semiconducting and dielectric layers; organic thin film preparation methods; morphological studies for organic thin films; electrical characterization of gate dielectric layers and semiconducting active layers; and characterization of the OTFTs. Future prospects and investigations required to improve the OTFT performance are also given. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.     

Compensation for volatile elements to modify the microstructure and energy storage performance of (W,Ni)-codoped Na0.5Bi0.5TiO3 ceramic films

This work reports the characteristics of nonstoichiometric Na_0.5+xBi_0.5+yTi_0.96W_0.01Ni_0.03O₃ (x?=?0.0%, y?=?1.0%; x?=?0.5%, y?=?2.0%; x?=?1.0%, y?=?4.0%) ceramic films derived from chemical solution deposition and the role played by excess Na/Bi in modifying microstructure and electrical properties. Single perovskite phase structure can be maintained in all compositions. Decreased grain size can be obtained with the increasing compensation for volatile Na/Bi elements. Particularly, extra amounts of 0.5?mol% Na and 2.0?mol% Bi leads to reduced leakage and enhanced ferroelectric polarization. Meanwhile, due to the high breakdown electrical field strength and large difference between maximum and remanent polarization, an excellent energy storage performance can be achieved in Na_0.505Bi_0.52Ti_0.96W_0.01Ni_0.03O₃ sample, which is distinguished by a recoverable energy storage density of 40.5?J/cm³ and an energy storage efficiency of 43.6% at 2515?kV/cm as well as a good frequency stability. Hence, the regulation for the content of volatile elements is effective to modify the electrical response of Na_0.5Bi_0.5TiO₃-based materials.     

TiO_2光催化薄膜的制备法

介绍了溶胶凝胶法制备TiO2 光催化薄膜的特点、原理和方法 ,并对TiO2 在非耐热基材表面的低温涂膜技术作了简要评述。     

Effect of rare earth doping on sol-gel derived PZT thin films

We have studied the effect of rare earth dopants (Nd, Gd and Ce) on the phase formation behavior and electrical properties of sol-gel derived Pb_1.05(Zr_0.53Ti_0.47)O₃ thin films. In all these films the perovskite phase is obtained up to 5 at% doping and beyond that pyrochlore phase was found to coexist with the perovskite phase. Ce and Gd doping(1-2 at%) exhibited improved ferroelectric and dielectric properties as compared to the undoped PZT films. Nd doping (2 at%) was found to be effective to increase the retained switchable polarization of undoped PZT from 63% to 84%. The transition temperature of undoped PZT film was found to be reduced with Nd doping. The Nd doped films also exhibited typical relaxor behavior and a diffuse phase transition, characteristic of the relaxor material. Introduction of Nd into the PZT lattice probably introduces disorder in the B site of ABO₃ lattice which causes the observed relaxor behavior     

Theoretical Aspects Of The Kinetics Of Competitive First Reactions Of Ozone In The O3/H2O2 And O3/UV Oxidation Processes

Kinetics of competition between the ozone direct reaction with compounds in water, ozone-hydroperoxide ion reaction leading to free radicals in the O₃/H₂O₂ process, and the photolysis of ozone in the O₃/UV process are discussed in terms of diffusion and reaction times to establish conditions for these reactions to be competitive. Film theory and chemical kinetic concepts then are applied to estimate initial rates of ozone absorption and consumption, removal rates of compounds present in water, and the importance of the radical oxidation path versus direct ozone and/or photolysis reactions.     

聚乙烯转光棚膜的加工及应用研究

本文对聚乙烯转光棚膜的加工和光转换剂的作用、配比关系及物理性能进行了讨论。     

Electrochemical synthesis of ba- and Sr-based titanate thin films using Ti electrode prepared by RF sputtering

Barium and strontium titanate films were electrochemically synthesized onto Ti thin film prepared by RF sputtering. Applied current waveform was modulated to investigate the film growth mechanism. Superimposed cathodic pulses accelerated the formation of titanate thin films, and both the electrode surface pH and (Ba²⁺, Sr²⁺) ion size had a strong influence on film formation. Titanate film formation mechanism was investigated with a scanning electron microscope, an X-ray diffractometer and an electrochemical quartz crystal microbalance (EQCM).Insitu mass change of Ti electrode during electrolysis indicated that electrochemical method sets a limit to film growth.