PDF Publication Title:
Text from PDF Page: 008
Stensberg et al. Page 8 produce two peaks, corresponding either to rotational diffusion [101] or to an anisotropic orientation relative to the light source [102]. Atomic force microscopy Scanning probe microscopies, such as atomic force microscopy, can provide complementary size and surface ana lysis of NPs bound to substrates, in liquid states as well as in air. Nanometer-sized probes are mounted on cantilevers and rastered across the sample, recording changes in forces as the probe tip interacts with the surface [103]. The lateral resolution of atomic force microscopy is lower than that of TEM due to limitations in tip size and shape; on the other hand, it is highly sensitive in the z-direction and is especially useful for depth profiling with nanometer resolution [104]. The cantilevers can also be functionalized to increase its sensitivity to surface properties and has been used to map electrostatic and chemical interactions [105,106]. Topological analyses based on such interactions do not necessarily reflect the true dimensions of nanostructured features, but rather an effective size based on physicochemical interactions [99]. Zeta potential Another important factor in the transport and fate of Ag NPs is their electrokinetic or zeta potential, measured in millivolts. This is typically defined by the electrostatic double layer surrounding each NP, which in turn is influenced by surfactant coatings and the ionic strength of the supporting medium [107]. NPs can form stable suspensions in aqueous solutions when their zeta potentials (typically negative) are above 30 mV. This is usually the case for particles dispersed in low ionic strength solutions, but their zeta potentials are reduced at higher ionic strength because the cations are more closely associated with the particle surface, which reduces the electrostatic double layer [98,108] and can lead to agglomeration [26]. It should be noted that the zeta potential is not the sole factor in NP stabilization; particles can also be sterically stabilized by organic surface coatings, independent of surface charge [100]. Brunauer Emmet Teller Specific surface area is yet another size-dependent factor in NP toxicity [96,109,110]. The specific surface area of NPs is much greater than that of their bulk counterparts and is an especially important issue in the case of aerosolized particles, which can enter the body through inhalation. The BET method is the most common method of quantifying exposed surface and has been used to measure the specific surface area of Ag NPs [95,109]. This method is based on the absorption of gas molecules onto the surface of the target analyte at a specified pressure. The specific surface area is then obtained as the ratio of the total surface area to the weight of NPs (in m2/g) [111]. Real-time physiological sensing The unique properties of Ag NPs have been found to interfere with some of the more traditional toxicological assays. To accommodate this interference researchers in the field of nanotoxicology have had to incorporate new techniques or modify existing techniques. Some of these techniques were recently reviewed [2]; however, this article will focus on the use of microsensors for real-time physiological sensing and the incorporation of advanced imaging techniques into toxicological studies. A logical first step for understanding the mechanisms of Ag NP toxicity is to compare the adverse effects with that of its ionic counterpart. The differential responses to Ag+ and Ag NPs can provide insights into the relationship between cell/tissue physiology and any size- dependent phenomena attributable to Ag NPs. Such information can be expected to be Nanomedicine (Lond). Author manuscript; available in PMC 2012 May 24. NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptPDF Image | Toxicological studies on silver nanoparticles
PDF Search Title:
Toxicological studies on silver nanoparticlesOriginal File Name Searched:
nihms-316964.pdfDIY PDF Search: Google It | Yahoo | Bing
Turbine and System Plans CAD CAM: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. More Info
Waste Heat Power Technology: Organic Rankine Cycle uses waste heat to make electricity, shaft horsepower and cooling. More Info
All Turbine and System Products: Infinity Turbine ORD systems, turbine generator sets, build plans and more to use your waste heat from 30C to 100C. More Info
CO2 Phase Change Demonstrator: CO2 goes supercritical at 30 C. This is a experimental platform which you can use to demonstrate phase change with low heat. Includes integration area for small CO2 turbine, static generator, and more. This can also be used for a GTL Gas to Liquids experimental platform. More Info
Introducing the Infinity Turbine Products Infinity Turbine develops and builds systems for making power from waste heat. It also is working on innovative strategies for storing, making, and deploying energy. More Info
Need Strategy? Use our Consulting and analyst services Infinity Turbine LLC is pleased to announce its consulting and analyst services. We have worked in the renewable energy industry as a researcher, developing sales and markets, along with may inventions and innovations. More Info
Made in USA with Global Energy Millennial Web Engine These pages were made with the Global Energy Web PDF Engine using Filemaker (Claris) software.
Infinity Turbine Developing Spinning Disc Reactor SDR or Spinning Disc Reactors reduce processing time for liquid production of Silver Nanoparticles.
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)