Deodorisation effect of diamond-like carbon/titanium dioxide multilayer thin films deposited onto polypropylene

Many types of plastic containers have been used for the storage of food. In the present study, diamond-like carbon (DLC)/titanium oxide (TiO₂) multilayer thin films were deposited on polypropylene (PP) to prevent flavour retention and to remove flavour in plastic containers.For the flavour removal test, two types of multilayer films were prepared, DLC/TiO₂ films and DLC/TiO₂/DLC films. The residual gas concentration of acetaldehyde, ethylene, and turmeric compounds in bottle including the DLC/TiO₂-coated and the DLC/TiO₂/DLC-coated PP plates were measured after UV radiation, and the amount of adsorbed compounds to the plates was determined. The percentages of residual gas for acetaldehyde, ethylene, and turmeric with the DLC/TiO₂ coated plates were 0.8%, 65.2% and 75.0% after 40 h of UV radiation, respectively. For the DLC/TiO₂/DLC film, the percentages of residual gas for acetaldehyde, ethylene and turmeric decreased to 34.9%, 76.0% and 85.3% after 40 h of UV radiation, respectively. The DLC/TiO₂/DLC film had a photocatalytic effect even though the TiO₂ film was covered with the DLC film.     

L~2(R~n)中MRA Parseval框架小波和它们的乘子

刻画了L~2(R~n)中具有扩展矩阵伸缩的广义低通滤波器和多尺度分析Parseval框架小波(缩写为MRA PFW).首先,研究了伪逆的尺度函数、广义的低通滤波器和MRA PFW,给出它们的一些刻画.接着,我们给出与MRA PFW相联系的几类乘子的一些刻画.最后,给出了一个例子来证明的结论.     

Polypropylene/poly(butyl methacrylate) blends prepared by diffusion and subsequent polymerization of butyl methacrylate in isotactic polypropylene pellets

Polypropylene/poly(butyl methacrylate)(PP/PBMA) blends were prepared by diffusion and subsequent polymerization of butyl methacrylate(BMA) in commercial isotactic polypropylene(iPP) pellets.The diffusion kinetics,diametrical distribution of PBMA in a pellet and phase morphology of a typical PP/PBMA blend were investigated.     

Gel production, oxidative degradation and dielectric properties of isotactic polypropylene irradiated under various atmospheres

In this work, changes in structure and physical properties of stabilized isotactic polypropylene (iPP) were created by gamma irradiation, up to a dose of 700 kGy, in different media: air, deionised distilled (DD) water and acetylene. Gel and infrared (IR) spectroscopy measurements were used to determine the changes in the degree of network formation and oxidative degradation, respectively. Sol-gel analysis was studied in detail using the Charlesby-Pinner (C-P) equation. The radiation-induced changes in the structure and evolution of oxygen-containing species were also studied through dielectric loss (tan δ) analysis in a wide temperature and/or frequency range. Evolution of low temperature dielectric relaxations with gamma irradiation was investigated. In the case of dielectric relaxation measurements, the polar groups that were introduced by irradiation in non-polar iPP were considered as tracer groups. Conclusions derived according to different methods were compared.     

Thermal oxidation of clay-nanoreinforced polypropylene

The thermo-oxidation process at low temperatures for a montmorillonite-nanoreinforced polypropylene (PP) was studied. Experimental aging kinetic data at 100, 80 and 60 °C have been obtained and compared with a computational simulation in which a kinetic model based on the closed loop approach was used. As a result, it has been found that the montmorillonite role is not limited to a role of inert filler in the polymer matrix but induces a slight catalytic effect leading to induction period reduction. This effect has been well simulated by increasing initial hydroperoxyde concentration. The consequences of kinetic control by oxygen diffusion have also been investigated by using micro ATR-FTIR mapping to assess concentration profiles of the oxidation products across the sample thickness. It has been found that the oxidized layer thickness is close to 17 μm for the pure polypropylene whereas it is around 10 μm for the nanocomposite at 100 °C. These profile variations have been attributed to differences in oxygen diffusion coefficient values. Simulations based on the kinetic model including diffusion-reaction coupling describe these profiles well.     

BEHAVIOR OF CHO CELLS ON MODIFIED POLYPROPYLENE BY LOW TEMPERATURE AMMONIA PLASMA

1. INTRODUCTION Bioreactors using membranes as substrates of cell cultures have become widely used for hybrid liver support systems [1]. For enhancing and prolonging the metabolism of the bioreactors, cytocompatible membranes are necessary because the cell culture is closely affected by the substrate surface. Surface factors considered to be important in cell culture are the concentration of ionic groups, the nature of polar and non-polar groups and the hydrophilic-hydrophobic balance [2].…     

Multi-color display and its model for a white OLED combined with optical color filters

A bright white organic light-emitting diode (OLED) has been successfully fabricated in which a greenish-white emitting host Bis-(2-(2-hydroxyphenyl) benzothiazole)zinc (Zn(BTZ)₂) is doped with an orange-red fluorescent dye 5,6,11,12-tetraphenylnaphthacene (rubrene). The pure white light emission with CIE coordinates of (0.341, 0.334) is achieved at the driving voltage of 20 V, and the corresponding luminance and external quantum efficiency are 4000 Cd/m² and 0.63%. On the other hand, the pure red, green, and blue (RGB) emissions are obtained from the white OLED combined well with RGB custom-built optical color filters (CFs) with peaks at 616, 556, and 456 nm, respectively. Moreover, based upon the color mixture principles, we build a model of multi-color display mixed by the pure RGB emissions under the controllable bias.     

利用非线性提升的信号去噪

本文提出了一种基于非线性滤波和提升格式进行信号去噪的算法。利用提升格式设计的灵活性取非线性滤波为预测算子 ,数值算例表明该方法的去噪效果优于仅使用非线性滤波去噪。     

The role of transient rheology in polymeric sintering

The initial theory of Frenkel and Eshelby for the coalescence of drops in air (or sintering) of Newtonian fluids, which equated the work of surface tension to the work done by viscous stresses while assuming biaxial extensional flow kinematics, was extended to the case of time-dependent material functions using the Upper Convected Maxwell (UCM) model. A numerical scheme was developed to solve the ordinary differential equations (ODE) for the stresses, which are embedded in the ODE based on the mechanical energy balance. Initial conditions required to solve the set of non-linear ODEs were obtained from visualization experiments of the coalescing drops as the theory for elastic contact gave unrealistically high values of the initial neck radius. The transient model predicted that coalescence was accelerated by increasing the relaxation time, the opposite relationship of what was predicted by the steady-state UCM formulation, and was capable of quantitatively predicting the experimental coalescence rates at times when viscoelasticity was important.