Interactions colloids

Surfaces can be characterized using scaiming probe microscopies (see section B1.19). In addition, by attaching a colloidal particle to tire tip of an atomic force microscope, colloidal interactions can be probed as well [27]. Interactions between surfaces can be studied using tire surface force apparatus (see section B1.20). This also helps one to understand tire interactions between colloidal particles. 

Crocker J C and Grier D G 1996 When like charges attract the effects of geometrical confinement on long-range colloidal interactions Phys. Rev. Lett. 77 1897-900... 

Figure 6.10 Effect of particle radius on colloidal interaction...

These problems have been improved in recent years by the microfabrication of sharp tips with radii less than 10 nm, the observation in an SEM or STEM of the exact radius before and after the experiment, the use of robust carbon-nanotube probes, and general improvements in control electronics. However, another method used initially was the attachment of a small colloid particle in place of the AFM tip. These particles were considered a reasonably good approximation to a single-asperity contact their radii were accurately known and remained the same for the duration of the experiment. Such probes have also been used to investigate colloids where surface roughness is an important aspect of the colloid interaction. 

Consideration of colloidal interactions and self-assembly 6.2.1 The unexpected behaviour of tiny objects... 

Heretofore the milieu on or in whieh the disinfectant has been required to act has been either solid or liquid now antibacterial aetion in the gas or vapour phase or in the form of aerosol (colloidal) interaction must be considered, and this presents the problem of determining the viable airborne population. 

An important issue in caramel applications is their compatibility with food. The compatibility is defined as the absence of flocculation, precipitation, and haze formation. These effects are the results of colloidal interactions between charged high molecular weight components of caramel and the food components thus the charge of caramel is essential for specific food applications. ... 

Helstad, K. M., Bream, A. D., Trckova, J., Paulsson, M., and Dejmek, P. (2005). Nano-heological properties of casein. In "Food Colloids Interactions, Microstructure and Processing", (E. Dickinson, Ed.), pp. 218-229. The Royal Society of Chemistry, Cambridge. 

Adhesion of bacteria to surfaces is believed to be mediated by long-ranging colloidal interactions, which hold bacteria in the close proximity of surfaces, thereby facilitating short-ranging hydrophobic interactions and adsorption of cell surface polymers to the surface. The extent of these interactions, and particularly the hydrophobic ones, depends strongly on the properties of... 

I. Philip, G. Gnana Prakash, T. layakumar, P. Kalyanasundaram, and B. Raj Three Distinct Scenarios under Polymer, Surfactant and Colloidal Interaction. Macro-molecules 36, 9230 (2003). 

Leal-Calderon et al. [13] have proposed some basic ideas that control the colloidal interactions induced by solvent or a mixture of solvent and solute, when varying their length from molecular to colloidal scale. They have investigated the behavior of water- and glycerol-in oil emulsions in the presence of linear flexible chains of various masses. Figure 3.7 shows the phase behavior of both water and glycerol droplets of diameter 0.4 pm when dispersed in a linear aliphatic solvent of formula C H2 +2, from n = 5 to n = 30. Because, for n larger than 16, solvent crystallization occurs at room temperature, a second series of experiments... 

S. R. Raghavan, J. Hou, G.L. Baker, and S.A. Kahn Colloidal Interactions between Particles with Tethered Nonpolar Chains Dispersed in Polar Media Direct Correlation Between Dynamic Rheology and Interaction Parameters. Langmuir 16, 1066 (2000). 

In this section we give a description of the colloidal interactions which govern the state of dispersion and rheology of calcium carbonate slurries. The description is based on a series of fundamental experimental studies that have been described in more detail in previous publications. ... 

In this situation, the equilibrium thickness at any given height h is determined by the balance between the hydrostatic pressure in the liquid (hpg) and the repulsive pressure in the film, that is n = hpg. Cyril Isenberg gives many beautiful pictures of soap films of different geometries in his book The Science of Soap Films and Soap Bubbles (1992). Sir Isaac Newton published his observations of the colours of soap bubbles in Opticks (1730). This experimental set-up has been used to measure the interaction force between surfactant surfaces, as a function of separation distance or film thickness. These forces are important in stabilizing surfactant lamellar phases and in cell-cell interactions, as well as in colloidal interactions generally. 

Mechanisms that may lead to the quasi irreversible binding of radionuclides to colloids belong to the key uncertainties of the assessment of the colloid problem. The kinetics of the dissociation of colloid-bound radionuclides are not yet understood. Radionuclide incorporation into stable colloids may enhance the colloid-mediated radionuclide release considerably. It is clear that only the investigation of the interaction mechanisms by spectroscopic methods is able to unravel the relevance of such processes. In order to allow the description of colloid-facilitated radionuclide migration, it is furthermore required to improve our understanding of the colloid interaction... 

Israelachvili, J., Wennerstrom, H. (1996). Role of hydration and water structure in biological and colloidal interactions. Nature, 379, 219-225. 

Semenova, M.G., Belyakova, L.E., Dickinson, E., Eliot-Laize, C., Polikarpov, Yu.N. (2005). Caseinate interactions in solution and in emulsions effect of temperature, pH and calcium ions. In Dickinson, E. (Ed.). Food Colloids Interactions, Microstructure and Processing, Cambridge, UK Royal Society of Chemistry, pp. 209-217. 

The successful application of food-grade biopolymers in the formulation of the next generation of smart delivery systems requires sound insight into the various intermolecular and colloidal interactions involved in the food matrix, along with some knowledge of the bioavailability in vivo. Furthermore, the impact of incorporated nutraceuticals on all the properties of a formulated functional food — appearance, physical/chemical stability, texture, mouthfeel, taste, flavour, bioavailability, and health impact — need to be simultaneously considered and addressed in order to achieve a balanced and acceptable solution for consumers. 

TABLE 4.4 Summary of Some Colloidal Interaction Energies and Parameters from Chapters 10-12... 

While in the case of noninteracting dispersions one needed to consider only the effect of the particle concentration, in interacting dispersions one needs to consider the time over which the flow behavior is observed and its magnitude relative to the time scales over which either shear or colloidal forces alter the local structure of the dispersions. What the flow behavior is, which interaction effects dominate the behavior, and how they do depend on the competing influences of the applied shear and interaction effects. In this section, we outline some of the important parameters one can formulate to judge the relative effects of various colloidal interactions and the physical significance of those parameters. 

Barnes, H. A., Hutton, J. F., and Walters, K., An Introduction to Rheology, Elsevier, Amsterdam, Netherlands, 1989. (Undergraduate and graduate levels. A practical introduction to the rheology of suspensions and polymer solutions. Chapter 2 presents introductory concepts and measurement techniques at the undergraduate level. Effects of colloidal interactions are not described.)... 

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