The use of light to mediate controlled radical polymerization has emerged as a powerful strategy for rational polymer synthesis and advanced materials fabrication. This review provides a comprehensive survey of photocontrolled, living radical polymerizations (photo-CRPs). From the perspective of mechanism, all known photo-CRPs are divided into either (1) intramolecular photochemical processes or (2) photoredox processes. Within these mechanistic regimes, a large number of methods are summarized and further classified into subcategories based on the specific reagents, catalysts, etc., involved. To provide a clear understanding of each subcategory, reaction mechanisms are discussed. In addition, applications of photo-CRP reported so far, which include surface fabrication, particle preparation, photoresponsive gel design, and continuous flow technology, are summarized. We hope this review will not only provide informative knowledge to researchers in this field but also stimulate new ideas and applications to further advance photocontrolled reactions.

http://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.5b00671

Light-Controlled Radical Polymerization: Mechanisms, Methods, and Applications

The generation of polymer brushes by surface-initiated controlled radical polymerization (SI-CRP) techniques has become a powerful approach to tailor the chemical and physical properties of interfaces and has given rise to great advances in surface and interface engineering. Polymer brushes are defined as thin polymer films in which the individual polymer chains are tethered by one chain end to a solid interface. Significant advances have been made over the past years in the field of polymer brushes. This includes novel developments in SI-CRP, as well as the emergence of novel applications such as catalysis, electronics, nanomaterial synthesis and biosensing. Additionally, polymer brushes prepared via SI-CRP have been utilized to modify the surface of novel substrates such as natural fibers, polymer nanofibers, mesoporous materials, graphene, viruses and protein nanoparticles. The last years have also seen exciting advances in the chemical and physical characterization of polymer brushes, as well as an ev...

Surface-Initiated Controlled Radical Polymerization: State-of-the-Art, Opportunities, and Challenges in Surface and Interface Engineering with Polymer Brushes

Gold nanoparticles (AuNPs) have stimulated a wide range of interest these past years due to their remarkable optical, electronic, and catalytic properties. Generally, the use of these nanoparticles requires their functionalization or combination with functional molecules, the nature of which depends on the target application. Among the numerous possibilities offered by chemistry, some recent papers report the coupling of AuNPs with molecularly imprinted polymers (MIPs) for the design of plasmonic-based AuNPs@MIP sensors. In such systems, a target analyte can be captured from a complex medium with a high specificity and selectivity owing to the exceptional chemical properties of the MIP matrix while the recognition event can be translated into a measurable physical signal (optical, electric, piezoelectric), the enhancement of which can be mediated by AuNPs. Despite such unique and intriguing advantages of AuNPs@MIP nanocomposites, there are still only limited numbers of studies regarding this field at the ...

Nanocomposites of Gold Nanoparticles@Molecularly Imprinted Polymers: Chemistry, Processing, and Applications in Sensors

Surface modified MXene Ti 3 C 2 multilayers by aryl diazonium salts leading to large-scale delamination

In this work, we propose an original strategy for the functionalization of aluminum nanoparticles (Al NPs), based on a combination of aryl diazonium salt chemistry and the photopolymerization iniferter method. It consists in grafting coupling agents, derived from diazonium salts, at the surface of Al NPs and in initiating the photopolymerization of methacrylic acid (MAA) directly from the surface. The hybrid NPs were fully characterized using XRD, TEM, TGA, and XPS. The results show that the obtained hybrids exhibit a core-double shell structure, the metallic core being preserved while a thin natural oxide layer and a strongly anchored organic shell surround it. The controlled and living character of the photopolymerization process allowed for the control of the polymer shell thickness with the polymerization time. Interestingly, the formation of compact aryl layers derived from the diazonium salts at the surface of Al NPs appears to provide an efficient protection against oxidation.

Functionalization of Aluminum Nanoparticles Using a Combination of Aryl Diazonium Salt Chemistry and Iniferter Method

Within the hypersonic context and the importance of the setting of an efficient cooling system, a specific laboratory test bench has been developed at ONERA within the framework of the Promethee program. Thus, the “Promethee Micro-Pilot” (MPP) allows the simulation of a cooling channel running of a hypersonic scramjet combustion chamber. In order to understand the cracking mechanisms and the behavior of a fuel in a supercritical context, the thermal cracking of a model fuel (a mixture of linear hydrocarbons: nC10H22, nC11H24, nC12H26, nC13H28) is carried out at high temperature between 600 and 900°C and under a pressure of 30 bar. For the lowest value of temperature (600°C), and thus at low parent hydrocarbon conversion, all the range of the n-alkanes with 1 to 9 carbon atoms and all the 1-alkenes with 2 to 10 carbon atoms are obtained. With the increase of the temperature, secondary products appear. They are isomerized olefins, dienes and cyclic hydrocarbons.

Determination of the decomposition products of a n-alkane endothermic fuel under supercritical conditions

Within the French Promethee Program on hypersonic airbreathing propulsion for missile applications, the development of a specific laboratory test bench was started by ONERA in 2001 in order to study the potential of endothermic fuels for cooling the structures of scramjet engines. Thus, the “Promethee Micro-Pilot” (MPP) allows the simulation of a generic cooling tube of a hypersonic scramjet combustion chamber. This device is really efficient for determining the behavior of a fuel and its evolution during the endothermic process. In order to contribute to the modeling effort about injection and combustion of decomposed products in a supersonic airstream, the decision was taken to connect the MPP to a hypersonic scramjet combustion chamber: the LAERTE test bench. With the two devices running together, it will be possible to study the different steps of the evolution of an endothermic fuel from the cracking, to the injection and the combustion. To properly adapt the coupling, we have to increase the reactor length. This unusual condition requires a parametric study with the MPP alone in order to determine the new composition and the degradation rate of the fuel. This article presents the results of this parametric study. The influence of the cracking temperature, the pressure and the mass flow rate were studied. For example, with the increase of temperature or with the reduction of mass flow rate, an increase of the degradation rates and the number of products were observed. With this study, we determined interesting working points. They will be reproduced with the MPP-LAERTE test bench.

Christian Masson

Papers

Functionalization of Aluminum Nanoparticles Using a Combination of Aryl Diazonium Salt Chemistry and Iniferter Method

Determination of the decomposition products of a n-alkane endothermic fuel under supercritical conditions

Thermal decomposition of a model endothermic fuel. Preliminary study before testing in the MPP-LAERTE supersonic combustion test bench.