480436-46-2Relevant articles and documents
Ab initio emulsion polymerization by RAFT-controlled self-assembly
Ferguson, Christopher J.,Hughes, Robert J.,Nguyen, Duc,Pham, Binh T.T.,Gilbert, Robert G.,Serelis, Algirdas K.,Such, Christopher H.,Hawkett, Brian S.
, p. 2191 - 2204 (2005)
A method is developed to enable emulsion polymerization to be performed under RAFT control to give living character without the problems that often affect such systems: formation of an oily layer, loss of colloidal stability, or loss of molecular weight control. Trithiocarbonate RAFT agents are used to form short stabilizing blocks from a water-soluble monomer, from which diblocks can be created by the subsequent polymerization of a Hydrophobic monomer. These diblocks are designed to self-assemble to form micelles. Polymerization is initially performed under conditions that avoid the presence of monomer droplets during the particle formation stage and until the hydrophobic ends of the diblocks have become sufficiently long to prevent them from desorbing from the newly formed particles. Polymerization is then continued at any desired feed rate and composition of monomer. The polymer forming in the reaction remains under RAFT control throughout the polymerization; molecular weight polydispersities are generally low. The number of RAFT-ended chains within a particle is much larger than the aggregation number at which the original micelles would have self-assembled, implying that in the early stages of the polymerization, there is aggregation of the micelles and/or migration of the diblocks. The latexes resulting from this approach are stabilized by anchored blocks of the hydrophilic monomer, e.g., acrylic acid, with no labile surfactant present. Sequential polymerization of two hydrophobic monomers gives completely novel core - shell particles where most chains extend from the core of the particles through the shell layer to the surface.
Polymer Self-Assembly Induced Enhancement of Ice Recrystallization Inhibition
Georgiou, Panagiotis G.,Marton, Huba L.,Baker, Alexander N.,Congdon, Thomas R.,Whale, Thomas F.,Gibson, Matthew I.
, p. 7449 - 7461 (2021)
Ice binding proteins modulate ice nucleation/growth and have huge (bio)technological potential. There are few synthetic materials that reproduce their function, and rational design is challenging due to the outstanding questions about the mechanisms of ice binding, including whether ice binding is essential to reproduce all their macroscopic properties. Here we report that nanoparticles obtained by polymerization-induced self-assembly (PISA) inhibit ice recrystallization (IRI) despite their constituent polymers having no apparent activity. Poly(ethylene glycol), poly(dimethylacrylamide), and poly(vinylpyrrolidone) coronas were all IRI-active when assembled into nanoparticles. Different core-forming blocks were also screened, revealing the core chemistry had no effect. These observations show ice binding domains are not essential for macroscopic IRI activity and suggest that the size, and crowding, of polymers may increase the IRI activity of "non-active"polymers. It was also discovered that poly(vinylpyrrolidone) particles had ice crystal shaping activity, indicating this polymer can engage ice crystal surfaces, even though on its own it does not show any appreciable ice recrystallization inhibition. Larger (vesicle) nanoparticles are shown to have higher ice recrystallization inhibition activity compared to smaller (sphere) particles, whereas ice nucleation activity was not found for any material. This shows that assembly into larger structures can increase IRI activity and that increasing the "size"of an IRI does not always lead to ice nucleation. This nanoparticle approach offers a platform toward ice-controlling soft materials and insight into how IRI activity scales with molecular size of additives.
Cell surface clicking of antibody-recruiting polymers to metabolically azide-labeled cancer cells
Uvyn, Annemiek,De Coen, Ruben,De Wever, Olivier,Deswarte, Kim,Lambrecht, Bart N.,De Geest, Bruno G.
supporting information, p. 10952 - 10955 (2019/09/18)
Triggering antibody-mediated innate immune mechanisms to kill cancer cells is an attractive therapeutic avenue. In this context, recruitment of endogenous antibodies to the cancer cell surface could be a viable alternative to the use of monoclonal antibodies. We report on antibody-recruiting polymers containing multiple antibody-binding hapten motifs and cyclooctynes that can covalently conjugate to azides introduced onto the glycocalyx of cancer cells by metabolic labeling with azido sugars.
Controllable Nanostructure Formation through Enthalpy-Driven Assembly of Polyoxometalate Clusters and Block Copolymers
Li, Dan,Jia, Xiangmeng,Cao, Xiao,Xu, Tianyang,Li, Haolong,Qian, Hujun,Wu, Lixin
, p. 4104 - 4114 (2015/06/30)
The coassembly of block copolymers (BCPs) with nanoscale inorganic objects is an important route to fabricate nanostructured polymer composites. However, the immiscibility of inorganic/polymeric interface is a recurring challenge to overcome, particularly for inorganic clusters, such as the polyoxometalates (POMs)/BCPs system. In this paper, we present a general method to incorporate POMs into BCP matrices, in which a POM cluster is embedded as a core in a supramolecular star polymer (SSP) whose arms possess the same chemical composition as a BCP segment. Because of the enthalpic interaction between SSP arms and BCP segments, the SSP can carry POM into BCP matrices to realize their coassembly. By this way, we successfully localize a Keggin-type POM cluster [CoW12O40]6- modified with polystyrene (PS) arms into the PS domain of poly(styrene-b-ethylene oxide) micelles, which induces the formation of a series of hybrid micelles with spherical, toroidal, and bicontinuous structures. The morphological transition of micelles can be adjusted by the length of PS arms and the content of cluster cores. The mechanism is studied by both experimental methods and simulations. An unconventional mechanism for toroid formation is disclosed for the first time, which follows a sphere-rosary-toroid pathway. Furthermore, the electrostatically bonded structure of SSP is found to play a crucial role on this pathway. These results not only pave the way for fabricating cluster-polymer nanocomposites with controllable structures but also provide new insights into comprehending the self-assembly behavior of complex polymer systems.
