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Nanoscale Particles (nanoscale + particle)
Selected AbstractsPreparation and Properties of PVC Ternary Nanocomposites Containing Elastomeric Nanoscale Particles and Exfoliated Sodium-MontmorilloniteMACROMOLECULAR MATERIALS & ENGINEERING, Issue 6 2006Qingguo Wang Abstract Summary: A novel rigid PVC ternary nanocomposite containing NBR-ENP and untreated Na-MMT has been fabricated. X-ray diffraction XRD, TEM and SEM observations revealed that the untreated Na-MMT was exfoliated and most NBR-ENPs (about 90 nm) were separately dispersed in the PVC matrix. DMTA and TGA demonstrated that the PVC ternary nanocomposites had a higher glass transition temperature and a higher decomposition temperature than neat PVC, while the toughness increased simultaneously. Combustion tests showed that the exfoliated clay in the PVC/NBR-ENP/MMT ternary nanocomposites did not improve the flame retardancy after ignition under strong heat flux. Schematic diagram of the fabrication procedure of PVC/NBR-ENP/Na-MMT ternary nanocomposites. [source] Controlled application and removal of liposomal therapeutics: Effective elimination of pegylated liposomal doxorubicin by double-filtration plasmapheresis in vitroJOURNAL OF CLINICAL APHERESIS, Issue 2 2010Gerhard Pütz Abstract Introduction: Nanoscale particle-based drug delivery systems like long circulating liposomal doxorubicin show unique pharmacokinetic properties and improved toxicity profiles. Liposomal doxorubicin accumulates in tumor tissue due to the enhanced permeation and retention effect, but only a small fraction of a total dose reaches the tumor site. Accumulation of liposomal doxorubicin is much faster in tumor sites than in certain organs where dose limiting adverse effects occur. Finding a way to detoxify the predominant part of a given dose, circulating in the blood after accumulation is completed, will presumably reduce severe side effects during chemotherapy. Methods: Elimination properties of therapeutic used pegylated liposomal doxorubicin (Doxil®/Caelyx®) and therapeutic used double-filtration plasmapheresis systems were evaluated in vitro and in reconstituted human blood. Results: Liposomes can be filtered by appropriate membranes without leakage of doxorubicin up to a pressure of 1 bar. At higher pressures, liposomes (,85 nm) may squeeze through much smaller pores without significant leakage of doxorubicin, whereas decreasing pore size to ,8 nm leads to increased leakage of doxorubicin. With therapeutic used apheresis systems, liposomal doxorubicin can be efficiently eliminated out of buffer medium and reconstituted human blood. No leakage of doxorubicin was detected, even when liposomes were circulating for 48 h in human plasma before apheresis. Conclusions: Convenient apheresis techniques are capable of a safe and efficient elimination of therapeutic used liposomal doxorubicin in an experimental model system. J. Clin. Apheresis, 2010. © 2010 Wiley-Liss, Inc. [source] Particle size distributions from small-angle scattering using global scattering functionsJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 4 2004G. Beaucage Control and quantification of particle size distribution is of importance in the application of nanoscale particles. For this reason, polydispersity in particle size has been the focus of many simulations of particle growth, especially for nanoparticles synthesized from aerosols such as fumed silica, titania and alumina. Single-source aerosols typically result in close to a log-normal distribution in size and micrograph evidence generally supports close to spherical particles, making such particles ideal candidates for considerations of polydispersity. Small-angle X-ray scattering (SAXS) is often used to measure particle size in terms of the radius of gyration, Rg, using Guinier's law, as well as particle surface area, S/V, from the Porod constant B and the scattering invariant Q. In this paper, the unified function is used to obtain these parameters and various moments of the particle size distribution are calculated. The particle size obtained from BET analysis of gas adsorption data directly agrees with the moment calculated from S/V. Scattering results are also compared with TEM particle-counting results. The potential of scattering to distinguish between polydisperse single particles and polydisperse particles in aggregates is presented. A generalized index of polydispersity for symmetric particles, PDI = BRg4/(1.62G), where G is the Guinier prefactor, is introduced and compared with other approaches to describe particle size distributions in SAXS, specifically the maximum-entropy method. [source] Nanotechnology and groundwater remediation: A step forward in technology understandingREMEDIATION, Issue 2 2006Christian Macé Nanotechnology application to contaminated site remediation, and especially the use of nanoscale zero-valent iron particles to treat volatile organic compound (VOC)-impacted groundwater, is now recognized as a promising solution for cost-effective in situ treatment. Results obtained during numerous pilot tests undertaken by Golder Associates between 2003 and 2005 in North America (United States and Canada) and Europe have been used to present a synthetic cross-comparison of technology dynamics. The importance of a comprehensive understanding of the site-specific geological, hydrogeological, and geochemical conditions, the selection of appropriate nanoscale particles, the importance of monitoring geochemical parameters during technology application, and the potential of nanoparticle impact on microbial activity are discussed in this article. The variable technology dynamics obtained during six pilot tests (selected among numerous other tests) are then presented and discussed. © 2006 Wiley Periodicals, Inc. [source] Production of Inorganic Nanoparticles by MicroorganismsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2009N. Krumov Abstract A promising new dimension in the field of biotechnology is the use of microorganisms for the production of inorganic nanoscale particles. The interest in nanotechnology is provoked by the unique properties of nanostructured materials and their potential fields of application ranging from medicine to electronics. This review article presents a systematic overview of the microorganisms capable of producing nanoparticles, and describes cellular mechanisms and outlines cultivation conditions that turn this process into a successful synthetic pathway. [source] | ||||||||||