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Mixing Techniques (mixing + techniques)
Selected AbstractsDegenerate and two-color resonant four-wave mixing applied to the rotational characterization of high-lying vibrational states of formaldehyde (Ã, 1A2),JOURNAL OF RAMAN SPECTROSCOPY, Issue 1-3 2006M. Tulej Abstract Degenerate and two-color resonant four-wave mixing techniques (DFWM and TC-RFWM) are applied to determine rotational constants of high-lying vibrational levels in the first excited singlet state Ã(1A2) of formaldehyde. It has been demonstrated that the sensitivity of the spectroscopic technique is applicable to the low-density environment of a supersonic molecular beam and to predissociating transitions displaying low fluorescence quantum yield. In addition, we take advantage of the superior selectivity of the double-resonance method, TC-RFWM, to isolate and assign transitions in the congested region of the (one-color) DFWM spectra. The line positions of 25 well-isolated transitions are determined in the band and yield the rotational constants A, B, C and the origin ,e. The accuracy of the constants is determined by performing the same procedure for the band where literature data is available for comparison. Copyright © 2006 John Wiley & Sons, Ltd. [source] Isothermal crystallization behavior of polyamide 6,6/multiwalled carbon nanotube nanocompositesPOLYMER ENGINEERING & SCIENCE, Issue 12 2009Shi-Ya Lin The good dispersion of functionalized multiwalled carbon nanotube (f-MWCNT) in polyamide 6,6 (PA 6,6) matrix was prepared by solution mixing techniques. The crystalline structure and crystallization behaviors of PA 6,6 and PA 6,6/f-MWCNT nanocomposites were studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and polarized optical microscopy (POM) analysis. DSC isothermal results revealed that the overall isothermal crystallization rates of PA 6,6 increased as well as the activation energy of PA 6,6 extensively decreased by adding f-MWCNT into PA 6,6, suggesting that the addition of f-MWCNT probably induces the heterogeneous nucleation. The effect of f-MWCNT on the chain arrangement for the crystallization of PA 6,6/f-MWCNT nanocomposites was also discussed. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers [source] A novel miniature mixing device for polymeric blends and nanocompositesPOLYMER ENGINEERING & SCIENCE, Issue 11 2009Martin Sentmanat A new miniature mixer has been developed to monitor and optimize the preparation protocol of various polymeric compounds and blend systems. The effect of mixing time and other basic processing parameters on the shear and extensional rheological properties of said compounds and blends is examined to understand the effect of undermixed and/or overmixed conditions on the rheological properties and thus the quality of the final products. Results from the new miniature mixer are compared with the results from other conventional mixing techniques to assess the scalability of the new mixing protocol. Two examples are used, those of polymer blending and nanocomposite formation. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers. [source] Production of Highly Loaded Nanocomposites by Dispersing Nanoparticles in Epoxy ResinCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 9 2010H. Nolte Abstract The objective of this study was the investigation of techniques for dispersing alumina nanoparticles with different surface modifications in epoxy resin. In order to prepare the matrix suspension, high contents of fillers (up to 50,wt,%) were dispersed by conducting shear mixing techniques in a high performance laboratory kneader. The intention was to attain solutions that were stable against re-agglomeration, while the mass fraction and the product fineness were maintained as high as possible. Therefore, both the formulations and the dispersion parameters were varied systematically. An epoxy resin was used as a carrier fluid and a corresponding amine hardener system was chosen. Tests were performed using alumina particles and surface modified alumina particles at different particle concentrations. Furthermore, the effect of diluting the colloidal suspensions and the resulting long term stability were also examined. The matrix suspension was examined with respect to viscosity, stability and particle size distribution. [source] | ||||||||||