Optimization Techniques with FORTRAN

Crystallization kinetics and nucleation activity of filler in polypropylene/surface-treated SiO2 nanocomposites

Effect of in situ prepared silica nano-particles on non-isothermal crystallization of polypropylene

Effects of organic nucleating agents and zinc oxide nanoparticles on isotactic polypropylene crystallization

The influence of nucleus density on optical properties in nucleated isotactic polypropylene

The effects of an organic phosphorus nucleating agent on the crystallization behavior and mechanical properties of poly(propylene) were investigated. As the concentration of nucleating agent increased from 0 to 0.8%, the tensile and flexural strengths of the nucleated poly(propylene) resin increased by 15%, the flexural modulus increased by 35%, the crystallization peak temperature increased by 10°C, and the nucleation density (calculated with the nonlinear Voltrra integral equation) increased by 106 times. Mechanical properties increased with nucleation density. Linear equations between the mechanical properties and the logarithmic nucleation density were revealed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 297–301, 2003

Effects of an organic phosphorus nucleating agent on crystallization behaviors and mechanical properties of poly(propylene)

The crystallization behavior of polypropylene (PP) copolymer obtained by in situ reactor copolymerization with or without a nucleating agent and/or nano-CaCO3 particles was investigated both by thermal analysis and by polarized light microscopy. The Avrami model is successfully used to describe the crystallization kinetics of the studied copolymer. The results of the investigation show that a dramatic decrease of the half-time of crystallization t1/2, as well as a significant increase of the overall crystallization rate, are observed in the presence of the nucleating agent. These effects are further promoted in the presence of the nano-CaCO3 particles. The incorporation of the nucleating agent and nano-CaCO3 particles into PP copolymer remarkably improved the mechanical properties and heat distortion temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 431–438, 2004

Crystallization behavior and mechanical properties of polypropylene copolymer by in situ copolymerization with a nucleating agent and/or nano-calcium carbonate

In TiO2-based perovskite solar cells (PSC), the preparation of the CH3NH3PbI3/TiO2 composite layer is very important, since the morphology of the perovskite adsorbed onto the surface of the TiO2 nanoparticles has decisive significance for the absorption of the incident sunlight and separation of the generated carrier. The traditional two-step spin-coating method for the deposition of CH3NH3PbI3 into the porous mesoporous TiO2 layer usually suffers from filling block problems. In this study, the PbO-TiO2 mesoporous layer was prepared with various ratios of Pb:Ti in the raw materials. Morphological, optical, and element analysis of the prepared thin films indicated that Pb was gradually mixed into the TiO2 mesoporous layer with the increased Pb:Ti ratios. The element distribution characteristics of the optimal thin films showed that the distribution of Pb was uniform throughout the whole TiO2 thin film, which indicates the successful mixing of Pb into the TiO2 electrode layer. Combined with dip coating, the PbO-TiO2 mesoporous layer was prepared into a CH3NH3PbI3/TiO2 composite layer and subsequently to a solar cell device. The prepared solar cell shows a short-circuit photocurrent density of 16.4 mA/cm2, an open-circuit voltage of 900 mV, a fill factor of 61%, and a power conversion efficiency (PCE) of 9.00%. The PCE of the PSC is promoted by nearly 25% when compared with that prepared with the traditional method. The proposed preparation method that combines TiO2 nanoparticle electrode with a mixing and dip coating provides a new effective way to improve the deposition of perovskite into the mesoporous TiO2 layer, which is very helpful for the fabrication of high-efficiency and low-cost PSC.

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Weiping Zhu

Papers

Effects of an organic phosphorus nucleating agent on crystallization behaviors and mechanical properties of poly(propylene)

Crystallization behavior and mechanical properties of polypropylene copolymer by in situ copolymerization with a nucleating agent and/or nano-calcium carbonate

The Properties of the CH3NH3PbI3/TiO2 Composite Layer Prepared from PbO-TiO2 Mesoporous Layer under Air Ambience