Polymer microgel

Zweigle, M.L. and Lamphere, J.C. "Crosslinked, Water-Swellable Polymer Microgels," US Patent 4,172,066(1979). 

In Fig. 48, the regions of the formation of linear or branched polymers, microgels and macrogels are shown as a function of the concentration of 1,4-DVB and of n-BuLi. Reactive microgels can be obtained at a monomer concentration below 50 g/1 and between 3 and 16 mol % of n-BuLi. The polymer structure approaches that of a macrogel when the concentration of 1,4-DVB or n-BuLi is increased. 

Zhang J, Xu S, Kumacheva E (2005) Photogeneration of fluorescent silver nanoclusters in polymer microgels. Adv Mater 17 2336-2340... 

Biffis et al. compared the catalytic performance of polymer gel immobilized Au NPs and Au/AC, with similar sized Au NPs, for alcohol oxidations in water [172]. Gold stabilized by polymer gel is advantageous over Au/AC for the use of hydrophobic substrates such as 1-octanol and 1-phenylethanol in aqueous media, although lower selectivity was obtained in some cases. For instance, polymer microgel supported Au NPs gave 1-octanoic acid by the oxidation of 1-octanol with a selectivity of 84% at 59% conversion, whereas Au/AC gave a selectivity of 93% at 65% conversion. 

Any colloidal material provides an intrinsically favorable accessibility to its surface when compared to bulk material. Therefore, the availability of receptor binding sites should be facilitated by using colloidal MIPs. Submicron scale MIPs were prepared by precipitation polymerization, emulsion polymerization, and miniemulsion polymerization. Precipitation polymerization uses the insolubility of the formed polymer microgel in a certain solvent, whereas emulsion and miniemulsion polymerization employ two solvent phases for the preparation of the colloidal polymer. The latter methods offer the opportunity for tailoring the surface of the colloids exclusively, thereby enhancing the accessibility of the binding sites. Each of the three approaches has their own characteristics and will be described in the following sections. 

Das M, Mordoukhovski L, Kumacheva E (2008) Sequestering gold nanorods by polymer microgels. Adv Mater 20 2371-2375... 

This volume is primarily concerned with the synthetic techniques for the preparation of aqueous polymer microgels having different architecture, chemical composition, size, surface charge and swelling but also demonstrates how sophisticated techniques enable the analysis of the complex structure of functional microgels. 

Coram et al. [6] have described the polymer support as a soluble macromolecule or a micellar aggregate that wraps the metal nanoparticle in solution, thus preventing metal sintering and precipitation. It can also be a resin, that is an insoluble material consisting in a bundle of physically and/or chemically cross-linked polymer chains in which the metal nanoparticles are embedded (Figure 11.2). Thus, soluble cross-linked polymers ( microgels ) that can stabilize metal nanoparticles can be prepared in addition, metal colloids protected by soluble linear polymers have been grafted onto insoluble resin supports to yield insoluble catalysts. This chapter is devoted mainly to metal nanoparticles on insoluble resin supports [8]. 

Nonaqueous dispersion polymer microgels have also found application as the main film former for certain types of exterior architectural coating where they give long term maintenance of mechanical properties leading to improved exterior durability on wooden substrates [3.94a]. 

S. D. Seiffert, Controlled fabrication of polymer microgels by polymer analogous gelation in droplet microfluidics. Soft Matter, 6, 3184-3190, 2010. 

Terashima T (2002) Polymer microgels for catalysis. In Encyclopedia of polymer science and technology. Wiley, New York... 

Velasco D, Tumarkin E, Kumacheva E (2012) Microfluidic encapsulation of cells in polymer microgels. Small 8 1633-1642... 

The swelling of polymer microgels in solution is usually described within the framework of the Flory-Rehner the-ory 135,136. 3 extended by Wu et al The osmotic... 

Figure 9.9 Dependence of the VPTT on the mol% of iPMA in polymer microgels.

Key words IR ultrathin films - LB films - amphiphilic polymer -microgel... 

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