Nanoparticle analysis

Pollutants—Analysis. 5. Environmental pollutants—Analysis. 6. Nanoparticles—Analysis. 

Gessner, A., Lieske, A., Paulke, B., and Muller, R. (2002), Influence of surface charge density on protein adsorption on polymeric nanoparticles Analysis by two-dimensional electrophoresis, Ear. J. Pharm. Biopharm., 54(2), 165-170. 

Nakamura, Y., and Hayashi, S. (2005). Enhancement of dye fluorescence by gold nanoparticles analysis of particle size dependence. Jap. J. Appl. Phys. 44, 9A 6833-6837. 

X-ray absorption spectroscopy is a powerful tool for nanoparticle analysis due to its selectivity and independence of sample physical state. It is limited in range to the region within about 0.5-0.7 nm of a particular (chosen) absorber atom in the structure, but can be applied to amorphous or even liquid samples. The basic theory behind the origins and analysis of the extended X-ray absorption fine structure (EXAFS) has been well described by Sayers et al. (1970, 1971) and Lee et al. (1981). with mineralogical applications detailed by Brown et al. (1988). The crucial aspect of the EXAFS spectrum is that it is formed by an electron backscattering process in the vicinity of the absorber... 

Anger, S., Caldwell, K.D., Mehnert W. and Muller, R.H. (1999) Coating of nanoparticles—analysis of adsorption using sedimentation field-flow fractionation (SdFFF), Proc. Int. Symp. Control. Rel. Bioact. Mater. 26, 599-600. 

One of the new trends in chemical analysis appeared in the last decade is that the miniaturization. It becomes apparent in the miniaturization of analytical devices, separation procedures, measuring tools, analyzing samples and as a consequent the term micro have appeared. Further development of this trend have led to transfer from the term micro to nano one (nanoparticles, nanofluides, nanoprobes, nanoelectrodes, nanotubes, nanoscale, nanobarcode, nanoelectrospray, nanoreactors, etc). Thereupon a nanoscale films produced by Langmuir-Blodgett (LB) technique are proposed for modifying of chemical sensors. 

Ebbesen[4] was the first to estimate a conductivity of the order of lO fim for the black core bulk material existing in two thirds of tubes and one third of nanoparticles. From this observation, it may naturally be inferred that the carbon arc deposit must contain material that is electrically conducting. An analysis of the temperature dependence of the zero-field resistivity of similar bulk materials[14,15] indicated that the absolute values of the conductivity were very sample dependent. 

An important question frequently raised in electrochemical promotion studies is the following How thick can a porous metal-electrode deposited on a solid electrolyte be in order to maintain the electrochemical promotion (NEMCA) effect The same type of analysis is applicable regarding the size of nanoparticle catalysts supported on commercial supports such as Zr02, Ti02, YSZ, Ce02 and doped Zr02 or Ti02. What is the maximum allowable size of supported metal catalyst nanoparticles in order for the above NEMCA-type metal-support interaction mechanism to be fully operative ... 

Starch capped ZnSe nanoparticles 3.1.3.1 Stmchiral analysis... 

The use of DNA as a template to fabricate mesoscale structures was also demonstrated in a recent work of Torimoto and coworkers. They used preformed, positively charged 3-nm CdS nanoparticles with a thiocholine-modified surface to be assembled into chains by using the electrostatic interaction between positively charged nanoparticle snr-faces and the phosphate groups of DNA. As determined by TEM analysis, the CdS nanoparticles were arranged in a qnasi-one-dimensional dense packing. This revealed interparticle distances of about 3.5 nm, which is almost equal to the height of one helical tnm of the DNA double strand [98]. 

Chui, Y.H., Snook, I.K. and Russo, S.P. (2007) Visualization and analysis of structural ordering during crystallization of a gold nanoparticle. Physical Review B -Condensed Matter, 76,195427-1—195427-6. 

Direct observation of molecular diffusion is the most powerful approach to evaluate the bilayer fluidity and molecular diffusivity. Recent advances in optics and CCD devices enable us to detect and track the diffusive motion of a single molecule with an optical microscope. Usually, a fluorescent dye, gold nanoparticle, or fluorescent microsphere is used to label the target molecule in order to visualize it in the microscope [31-33]. By tracking the diffusive motion of the labeled-molecule in an artificial lipid bilayer, random Brownian motion was clearly observed (Figure 13.3) [31]. As already mentioned, the artificial lipid bilayer can be treated as a two-dimensional fluid. Thus, an analysis for a two-dimensional random walk can be applied. Each trajectory observed on the microscope is then numerically analyzed by a simple relationship between the displacement, r, and time interval, T,... 

There exist numerous reports on the interaction of noble metal nanoparticles, especially those of gold, with DNA. The reason for this intense work in most cases is the use of gold nanoparticles for the analysis of nucleic acids, or proteins. In any case, the interactions between the two... 

PtRu nanoparticles can be prepared by w/o reverse micro-emulsions of water/Triton X-lOO/propanol-2/cyclo-hexane [105]. The bimetallic nanoparticles were characterized by XPS and other techniques. The XPS analysis revealed the presence of Pt and Ru metal as well as some oxide of ruthenium. Hills et al. [169] studied preparation of Pt/Ru bimetallic nanoparticles via a seeded reductive condensation of one metal precursor onto pre-supported nanoparticles of a second metal. XPS and other analytical data indicated that the preparation method provided fully alloyed bimetallic nanoparticles instead of core/shell structure. AgAu and AuCu bimetallic nanoparticles of various compositions with diameters ca. 3 nm, prepared in chloroform, exhibited characteristic XPS spectra of alloy structures [84]. 

EXAFS analysis is a powerful spectroscopic method for structural analysis which has been extensively applied to the problem of structure determination in nanoparticles, and especially bimetallic nanoparticles [170-172]. The X-ray absorption spectrum of an element contains absorption edges corresponding to the excitation of electrons from various electronic states at energies characteristic of that element, i.e., K edges arise from the excitation of electrons from Is states, and LI, II, III edges from excitations from 2s, 2p 1/2, and 2p3/2 states. When the X-ray energy is increased above an edge, oscillations (fine... 

Recently we investigated ferromagnetic properties of CoPt bimetallic nanoparticles [232,233]. CoPt3 nanoparticles can be prepared by a two-step reduction using NaBH4 as a reductant. The bimetallic nanoparticles were characterized by thermogravimetry (TG) and differential thermal analysis (DTA), FT-IR, TEM) and XRD. Structural and spectroscopic studies showed that the bimetallic nanoparticles adopt an fee crystalline structure with an average particle size of 2.6 nm. SQUID studies revealed... 

Figure 6. Thermogravimetric analysis (TGA) of free 55 K PVP and 7.1 nm Pt-PVP nanoparticles in oxygen. Oxidative decomposition of free PVP begins at 573K, while significant weight loss due to the catalyzed oxidation of PVP on PVP-protected Pt nanoparticles occurs at 473 K. It appears that PVP layer is not a complete monolayer or the entanglement of PVP chains causes a porous polymer layer enabling oxygen diffusion to the nanoparticle surface [17]. (Reprinted from Ref [17], 2006, with permission from Springer.)...

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