"Grafting through" polymerization represents copolymerization of free monomers in solution and polymerizable units bound to a substrate. Free polymer chains are formed initially in solution and can incorporate the surface-bound monomers, and thereby, get covalently bonded to the surface during the polymerization process. As more growing chains attach to the surfacebound monomers, an immobilized polymer layer is formed on the surface. We use a combination of computer simulation and experiments to comprehend this process for monomers bound to a flat impenetrable substrate. We concentrate specifically on addressing the effect of spatial density of the surface-bound monomers on the formation of the surface-attached polymers. We employ a lattice-based Monte Carlo model utilizing the bond fluctuation model scheme to provide molecular-level insight into the grafting process. For experimental validation, we create gradients of density of bound methacrylate units on flat silicon wafers using organosilane chemistry and carry out "grafting through" free radical polymerization initiated in bulk. We report that the proximity of the surface-bound polymerizable units promotes the "grafting through" process but prevents more free growing chains to "graft through'' the polymerizable units. The "grafting through" process is self-limiting in nature and does not affect the overall density of the surface-bound polymer layer, except in case of the highest theoretical packing density of surface-bound monomers.

In many applications, a functional additive is blended into a polymer matrix to enhance its properties. However, when the polymer and functional additive are applied to a surface, the functional molecule may be easily lost. In favorable cases, it may be possible to incorporate the additive directly into the polymer as a comonomer. In this study, a functionalized polymer has been obtained through the combination of linking a photodynamic, antimicrobial dye, Rose Bengal, to vinyl benzyl chloride via etherification and then polymerizing this into a water-soluble polymer using chain growth copolymerization.Characterization of the efficiency of synthesis, solubility of the final product, and singlet oxygen production rate has been performed. Dialysis was used to determine the extent of incorporation of the dye into the polymer. The chemical structure of the intermediate produced through etherification has been verified.

Polymer degrafting is a process in which surface-attached polymer brushes are removed from the substrate by breaking a chemical bond in proximity to the substrate. This paper provides insight into the kinetics of degrafting poly­(methyl methacrylate) (PMMA) brushes using tetrabutyl­ammonium fluoride (TBAF) and demonstrates how the process can be modeled using a series of degrafting reactions. The trichlorosilane-based polymerization initiator utilized here to synthesize PMMA grafts by surface-initiated atom transfer radical polymerization anchors to the silica substrate by up to three potential attachment points. During the degrafting sequence this anchoring reduces to two and one chemical bond and finally results in complete liberation of the PMMA macromolecule from the substrate. We investigate the effect of TBAF concentration, the initial grafting density of PMMA grafts on the substrate, and TBAF exposure time on degrafting of PMMA by monitoring the instantaneous areal grafting density of PMMA on the substrate.

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We employ a Monte Carlo simulation scheme based on the bond fluctuation model to simulate template polymerization via controlled polymerization scheme involving copolymerization of free monomers (A) and monomers bound to a template (B) that consists of linear or ring-like substrates with equidistant sites occupied by bound B monomers. Both A and B are chemically identical; i.e., there is no interaction potential acting between A and B. A new macromolecule is initiated in bulk by activation of an initiator; any monomer that is within the reaction distance (nearest neighbors) of the initiator can be incorporated into the chain. As the macromolecule grows, it adds either bulk (i.e., A) or template-bound monomers (i.e., B) to its chain. The living nature of the polymers is assured by eliminating any termination or chain transfer. We analyze the effect of the number and spacing of the B bound monomers on the substrate on the chemical composition and monomer distribution in the resultant A−B random copolymer. Our results reveal that the likelihood of B being incorporated in the A−B copolymer increases with increasing the number and density of the B monomers on the template substrate; the maximum sequence length of "polymerized" bound B monomers increases with increasing the number of bound B monomers present in a single substrate. Long consecutive sequences of B bound monomers in the A−B copolymer are formed when the B bound monomers are immobilized in space in high densities.