Colloids multimodal

However, TEM measurements performed on a Pt0 83Sn017/C (Figure 9.15) indicated that the increase of the metal loading on the carbon support led to the formation of a multimodal distribution of the particle size. Then, to overcome this problem, colloidal methods were also developed in our laboratory. 

Hoffman, R. Factors affecting the viscosity of unimodal and multimodal colloidal dispersions. J. Rheol, 36(5) 947-965, 1992,... 

The distribution function of the activation energy of the shear viscosity shifts toward higher energy with increasing Cp s value (Figure 1.260b). The structure of the dispersion becomes more complex since the/( ) function is multimodal at CpMs=5 wt%. The viscosity of the aqueous suspension of nanosilica even at higher concentration (8 wt%) is lower and the f(E) peak is at lower E values. Features of different interactions between colloidal particles of PMS or nanosilica... 

The force measurements were done by the colloidal probe technique in contact mode using a NanoScope III MultiMode AFM (Digital Instruments, California) equipped with a fluid cell and a scanner E, vertical engagement, using an 0-ring. When measuring forces between cellulose beads, the bead attached to the cantilever was placed directly on top of a bead on the sample support. The position of the bead was checked using the optical microscope of the AFM instrument. 

At elevated concentrations, light-scattering spectra of solutions of colloidal spheres become multimodal. Correspondingly, as required by Doob s theorem, particle motions cease to be described by a Gaussian random Markoff process. Segre, et al. report t), as obtained using a two-color, two-detector homo-... 

Atomic Force Microscopy (AFM) and Transmuision Electron Microscopy (TEM). Measurements were carried out with a MultiMode AFM (Digit Instruments). The tapping mode was applied. The polymer was dissolved in 2,2,3,3-tetrafluoro-l-propanol or THF and a film was formed by slow evaporation of the solvent at ambient temperature. The samples for TEM were dissolved in water and in some cases colloidal gold was added. The solutions were cast onto copper grids covered with a carbon fihn. A Zeiss-CEM902 was used with an acceleration voltage of 80 kV. 

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