Surface Modification of Polymers by Reaction of Alkyl Radicals

Abstract

The surfaces of poly(methyl methacrylate) and polyethylene are modified either (i) by a two-step process including the thermal reaction of alkyl radicals derived from bromohexanoic acid in a mixture of 2,6-dimethylbenzene diazonium salt and neat isopentyl nitrite at 60 °C, followed by reaction with p-nitroaniline, anthraquinone, neutral red, and polyethylene glycol moieties, or (ii) by reaction of a previously anthraquinone-modified bromohexanoic acid. The modified surfaces are characterized by IR, XPS, UV, and water contact angles. A mechanism is proposed to rationalize the results. This approach is an efficient way to modify and pattern polymer surfaces with different organic groups and chemical functionalities under mild conditions.

Simultaneous bioconversion of lignocellulosic residues and oxodegradable polyethylene by Pleurotus ostreatus for biochar production, enriched with phosphate solubilizing bacteria for agricultural use

“…ostreatus , signals at 3,500–3,000 cm -1 corresponding to hydroxyl (C-OH) group were described before [27], as observed in the present work. Presence of polar groups favored LDPE oxo hydrophilicity (Table 1), [42,74], which allowed P . ostreatus to use the polymer as a substrate, and colonize it (Fig 2C and 2D).…”

“…pH and moisture percentage were determined following the methodology reported in Colombian Technical Standard 5167 of 2011 [42]. CO 2 production was determined by the respirometry method.…”

Continuous Synthesis of Nanocrystals via Flow Chemistry Technology

“…Obviously, microreactors have large areas, which, on one hand, enhance the heat exchange between reaction and external environments (the heat transfer performance of microreactor will be shown in the next section), but, on the other hand, it is very easy to cause particle adsorption and accumulation in the reactor, which will reduce the yield of the reaction, and might further block the channel in microreactor. To overcome the negative effect of particle adsorption, surface coating methods can be used to control the wetting property of the reactor,33b,47 and using an inert continuous phase to block the contact of nanoparticles and reactor inner surface is also straightforward, such as the reaction process for anisotropic Au nanoparticles proposed by Duraiswamy and Khan, as shown in Figure d. In recent years, many reports have indicated the advantages of segment flow in the preparation of nanocrystals.…”

Powerful Surface Chemistry Approach for the Grafting of Alkyl Multilayers on Aluminum Nanoparticles

“…The mechanism for the formation of ∼7 nm multilayers (reaction R9) would involve a hydrogen atom abstraction from an already grafted group to give a bonded radical that would couple with a radical in solution, as already observed during the indirect grafting of alkyl halides on carbon. 22 This implies that RI could diffuse toward the surface through the first grafted layers or that electrons would tunnel through the layer to produce radicals in solution.…”

“…22 The general mechanism of the electrografting reactions involves the formation of an alkyl radical that reacts with the surface, 23 in competition with its further reduction to a carbanion. Strongly attached disordered mono-or multilayers are obtained by this method, with the interaction between the grafted alkyl films and the metallic surface being very stable.…”