Microgels composite gels

Composite Gels and Microgels with Cellulose Blocks. 229... 

Another promising field of application of Th-FFF is the investigation of gel/microgel mixtures with polymers as pioneered by Lee et al. [355,356], A major advantage is that for the Th-FFF experiment no filtration is required to endanger material loss. For example, microgels or particles which are problematic for SEC separations can be separated from a polymer, so that the major constituents of composites such as acrylonitrile-butadiene-styrene (ABS) rubber are quantitatively accessible. 

When liquid-liquid phase separation occurs, resulting in water-in-water emulsions where the different biopolymers are concentrated in the different phases, and when one or both phases can gel, these systems can be used to produce anisotropic microgel particles and/or gel composites with anisotropic inclusions, resulting in a variety of interesting microstructures and morphologies. An interesting concept to generate alternative gel structures with basis on phase separated biopolymer blends... 

Rgure 8.6 Representation of the variety of polymer morphologies in solution and in the gel (or microgel) or solid states. In solution the conformation of the polymer depends on the nature of polymer-solvent interactions and whether or not the polymer chains associate to form micellar aggregates. Crystals of polymer and microcrystals can be prepared, and gels can be formed from covalently crosslinked or polymer chains associated by hydrogen bonding or hydrophobic interactions. Listed are the forms in which most polymers can be fabricated membranes, fibres, composites, matrices microspheres and microcapsules can also feature, as discussed later in this chapter. 

The formation of networks by addition polymerization of multifunctional monomers as minor components included with the monofunctional vinyl or acrylic monomer is industrially important in applications as diverse as dental composites and UV-cured metal coatings. The chemorheology of these systems is therefore of industrial importance and the differences between these and the step-growth networks such as amine-cured epoxy resins (Section 1.2.2) need to be understood. One of the major differences recognized has been that addition polymerization results in the formation of microgel at very low extents of conversion (<10%) compared with stepwise polymerization of epoxy resins, for which the gel point occurs at a high extent of conversion (e.g. 60%) that is consistent with the... 

HAp NCs are homogeneously distributed in the micro-gel shell and the loading of inorganic material in the composite particles can be varied in a broad range. The incorporation of HAp NCs reduces the colloidal stability of the microgels and decreases their ability of changing the size as response to the temperature variation. The chemical structure of HAp NCs incorporated into microgels has... 

Figure 8.10 Microfluidic generation of micro-gel-based cellular microenvironments with varying internal compositions, (a) Co-emulsification of two cell suspensions to achieve control over the ratio of co-encapsulated "red" and green" cells by varying the volumetric flow rates of the suspensions, Qr and gc. respectively, (b) Control of the mechanical properties of cell-laden microgels achieved by varying agarose concentration in the micro-...

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