Photochemically Prepared Gold/Polymer Nanocoatings: Formation of Gold Mirror

Abstract

In this study a rapid method is developed to obtain Au nanoparticles (AuNPs)/polymer composite materials by which HAuCl 4 salt is reduced and a polymer matrix is simultaneously generated by the means of UV light. 2-Mercaptothioxanthone (TX-SH), thioxanthone (TX), and TX + thiophenol are used as photoinitiator system for the poly(ethylene glycol) methyl ether acrylate and poly(ethylene glycol) diacrylate mixtures in the presence of HAuCl 4 . Except for a few studies, in situ reduction of Au ions, in an attempt to make them near or at polymer surface, has hardly been investigated at all. As a result of this study, it is important to note that the change of shape of NPs depends on the photoreducing species. TX-SH, due to thiol functionality in its structure, helps the production of the size, shape, and controlled distribution of AuNPs either in polymer matrix or in solution. Prepared AuNPs/polymer nanocoatings exhibit a reflected gold mirror view depending on the irradiation time. In addition to the foregoing approach in obtaining a thin film in the presence of AuNPs, it is expected that they are well ordered near the film surface with controlled shape and narrow range in size distribution.T. Çeper, Prof. N. Arsu Department of Chemistry Yildiz Technical University Davutpasa Campus Istanbul 34220, Turkey E-mail: narsu@yildiz.edu.tr the literature [6][7][8][9][10][11] but controlling size and shape as well as good distribution of NPs without agglomeration are still challenging areas for research. Most of the properties of NPs, such as catalytic, optical, etc., are clearly size dependent. [11,12] Usually photopolymerizable formulations consist of photoinitiators, oligomers, reactive diluents, and additives. Among these constituents, the photoinitiator plays an important role in the final properties of the cured coating as well as the oligomers and reactive diluents. Photoinitiators can be classed as cleavable and abstractable types. Cleavable initiators are called Type I and are less prone to oxygen inhibition. Type II are of the initiators hydrogen abstracted type and generally needs a hydrogen donor such as the amines and acids to produce initiating radicals. Among them thioxanthones are the most important Type II initiators. [13][14][15][16][17][18][19][20][21][22][23][24] Recently, several thioxanthone derivatives which are mercapto [13] water soluble [14,15,22] panchromatic, [24] polymeric, [14][15][16][17] and visible [18][19][20][21][22][23] photoinitiators were synthesized and their initiating efficiencies were reported.Type I and Type II initiators were used by several research groups for the preparation of Ag, Au, and

Light-Assisted Synthesis of Silver and Gold Nanoparticles by New Benzophenone Derivatives

“…The absorbance red-shifts to lower energies when the distance between the particles increases or decreases. The silver nanoparticles, then, seem brown and yellow, while the gold nanoparticles illustrate purple and blue tones. − A metal’s Surface plasmon resonance “SPR” band can be defined as these distinguishing plasmon resonance absorbances. , The frequency of oscillations depends on the metal, the particle size and shape, the interparticle distance, temperature, dielectric constant, and viscosity of the medium . Noble metals demonstrate an intense resonance because of the strong coupling between the plasmon transition and interband excitation.…”

Novel Copper Photoredox Catalysts for Polymerization: An In Situ Synthesis of Metal Nanoparticles

“…The shape of AuNPs is mainly spherical, and the size is controlled. The size, shape, and distribution of AuNPs were facilitated by HLCuCl, but the ethylene glycol-based acrylic monomer also contributed to this due to the chelation effect [ 22 ]. A difference in size is observed with ranges between 37 and 200 nm (see Figure 7 ).…”

“…Nano-coatings are generally prepared by UV irradiation formulations containing dispersed nanoparticles [ 16 ]. An in situ photo-polymerization process was used to prepare Ag and Au nanoparticles, as reported in the literature [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 ].…”

Thermal and morphological investigation of the effect of POSS‐(PEG2000)8 addition to UV curable PEGMEA/PEGDA formulation and simultaneously in situ formed silver nanoparticles

“…Many studies have been published in which photoinitiator molecules are used simultaneously both as initiators for polymerization and as photoreducing agents for Np synthesis. [21][22][23][24][25][26] Photoinitiators are the main component in this technique and they greatly affect the properties of the polymeric film. 2-mercaptothioxantone and thioxanthone acetic acid derivatives, one-component type II photoinitiators, have been used in the photochemical synthesis of various metal and metal oxide Nps.…”