Wen Juan Gu

Preparation of Silica Hollow Spheres Used as Filler for Paper

Silica of hollow structure exhibits a number of special characteristic. In this paper, a new way to prepare hollow silica spheres which can be used as filler for paper was reported. In this approach, when silica shells were coated on polyvinylacetate (PVAc) template particles by the sol-gel method, the PVAc cores would be dissolved synchronously, forming hollow spheres. Neither additional dissolution nor a calcination process was needed to remove the PVAc cores. The morphology of the hollow silica spheres was also characterized by TEM. It was shown that the hollow silica spheres with 130-400nm in diameter and 15-35nm in the shell thickness could be synthesized. The possible formation mechanism was also brought forward. The possibility and potential advantages in usage as filler for paper were analyzed theoretically. We confer that this filler can improve the printability of the paper, and reduce its density compared with traditional fillers.

Printing Industry and the Environment

Development of green economy is the only way to relieve the restriction of resource, which is the effective and important way to improve economical benefit radically. Only in this way can continuable development be achieved. The research on pollution in printing industry was reported in this paper. The general pollutant such as solvents, exhaust gas, ink, and etc were summarized. The existing methods, measures and technologies which could solve or relieve the pollution of the printing industry on the environment were brought forward. The suggestions were advanced from country, enterprise, individual to science development aspects. The prospect would be fine with the efforts of the government, enterprise and human being.

Synthesis and Characterization of Star-Shaped Polylactic Acid with Polyhedral Oligomeric Silsesquioxanes

A series of star-shaped polylactic acid was synthesized using L-lactic acid (L-LA) and octa(γ-chloroammoniumpropyl) octasilsesquioxane (POSS-NH3Cl) by in the presence of stannous(II) octanoate (Sn(Otc)2) catalyst. The structures and properties of these dendritic polymers were characterized by FTIR, 1H-NMR and TGA, respectively. These results demonstrated that the chemical reaction between POSS-NH3Cl and L-LA had been taken place, and the novel star-shaped polylactic acid (POSS-g-PLLA) had been synthesized. And thermal properties, such as melting temperature and decomposition temperature, were obviously improved along with the increment of the added amount of POSS-NH3Cl. The decomposition temperature of POSS-g-PLLA was higher ca. 70°C higher than that of PLLA, also higher 65°C than that of POSS-NH3Cl/PLLA.

Research on the Relationship between Drying Method and Binder Distribution by Tracing Technique

To observe binder distribution, and obtain the relationship between drying method and binder distribution in the z-direction, Rhodamine B was used to stain the binder and as the probe to characterize z-directional distribution of the binder using LSCM. The results implied that it was reliable and effective method using LSCM to characterize the z-directional distribution of binder and analyze the influence of dry method on binder migration. It could be concluded that the dry method was critical to binder distribution in coated paper and vacuum drying accelerated binder migration to the base paper, however vacuum drying made uniform binder distribution. Infrared drying was good to producing little binder migration towards the interior of base paper, but infrared drying was disadvantageous to even binder distribution.

Investigation into Coating Surface Free Energy and Microstructure of Coated Paper Related to Pigment

The physical structure of coating layer have an important influence on transferring and setting of the printing ink. In this study, the effect of pigment on surface microstructure and surface free energy was investigated. The findings indicated that the pigment affected the pore size, depth and distribution of the coated paper surface. Kaolin pigment compared with calcium carbonate pigment was good to improve the paper surface smoothness. Surface free energy of kaolin pigment coating was higher than calcium carbonate pigment coating, which showed that surface wettability of coating with kaolin pigment was better than calcium carbonate pigment.

Synthesis of Silica Microspheres Filler for PDMS

A new kind of silica microspheres were first synthesized with chloropropyltrimethoxysilane (WD30) and tetraethoxysilane (TEOS) by sol-gel method. And hybrid membrane was prepared by incorporating the as prepared filler into polydimethylsiloxane (PDMS). The IR, swelling density(Dsw) and mechanical properties of these composites membranes were studied by means of IR analysis and tensile testing. The experimental results showed that both mechanical properties of these composites were significantly improved by using the as-synthesized filler. The filler synthesized in this research not only increased the volume and reduce the cost of HPDMS, but also reacted with the PDMS. The vulcanztion density was increasedwith the interaction between the filler and the PDMS chains. This new kind of silica microspheres is an effective reinforcement filler for PDMS composite.

Preparation of PVAc Particles by Dispersion Polymerization

Highly uniform polyvinylacetate particles of submicron size were prepared by dispersion polymerization in mixed media of isopropanol and water initiated by redox initiator of NaHSO3 and K2S2O8 using poly(N-vinylpyrrolidone) as stabilizer. Monomer conversion was studied gravimetrically. Both the morphology and the size of the particles were measured by TEM. The influences of various polymerization parameters, such as monomer concentration, stabilizer content, on the particle properties were systematically investigated. The PVAc particles synthesized in this research were mono-disperse spheres with the diameter between 100-1000 nm.

The Statics Analysis of the Lathe Tool Based on Workbench

The 3D model of the lathe tool is established by using the Pro/E of 3D design software, then imported 3D model into the finite element software Workbench, and analyzed its statics using the finite element method, and got the stress figure and strain figure and total deformation figure while the lathe tool undertaking the cutting force, through the analysis it shows that the strength of the lathe tool can meet the processing requirements.

The Development of Tribology

In the past 20 years, with the rapid development of nanotechnology and increasing peoples social needs, tribology gained the rapid development. Meanwhile, many new areas produced. This article describes a simple spherical roller bearing down tribology design. Thus the development of tribology and trends are explained.

Numerical Characterization of the Effect of Coating Solid on Binder Distribution

Binder is the essential component of coating color recipe. The amount and type of latex binder has a significant effect on both the structure and chemical-physical properties of coated paper, which affect critical surface properties, e.g., print gloss, roughness, ink setting rate via liquid absorption, and print mottle The main aim of this study was to investigate the effect of coating solid on the binder distribution in the method of numerical analysis by Laser Scanning Confocal Microscope (LSCM). In this study, Rhodamine B was used to stain the binder and as the probe to characterize z-directional distribution of the binder using LSCM. The results implied that it was reliable and effective method using LSCM to characterize the z-directional distribution of binder and analyze the influence of coating solid on binder distribution in the z-direction. It could be concluded that the coating solid played an important effect on binder distribution in coated paper and low coating solid with more water accelerated binder migration to the interior of base paper, sample with 60% coating solid is good to binder distribution and coating layer forming.