Recent Biomedical Applications of Coupling Nanocomposite Polymeric Materials Reinforced with Variable Carbon Nanofillers

The hybridization between polymers and carbon materials is one of the most recent and crucial study areas which abstracted more concern from scientists in the past few years. Polymers could be classified into two classes according to the source materials synthetic and natural. Synthetic polymeric materials have been applied over a floppy zone of industrial fields including the field of biomedicine. Carbon nanomaterials including (fullerene, carbon nanotubes, and graphene) classified as one of the most significant sources of hybrid materials. Nanocarbons are improving significantly mechanical properties of polymers in nanocomposites in addition to physical and chemical properties of the new materials. In all varieties of proposed bio-nanocomposites, a considerable improvement in the microbiological performance of the materials has been explored. Various polymeric materials and carbon-course nanofillers were present, along with antibacterial, antifungal, and anticancer products. This review spots the light on the types of synthetic polymers-based carbon materials and presented state-of-art examples on their application in the area of biomedicine.

Generating highly reflective and conductive metal layers through a light-assisted synthesis and assembling of silver nanoparticles in a polymer matrix

The development of metalized surfaces exhibiting mirror properties and/or electric conductivity without heavy equipments and with low metal charge is a big challenge in view of many industrial applications. We report herein on the photo-assembling of silver nanoparticles (AgNPs) in a polymer matrix, carried out within minutes from an acrylate monomer and silver nitrate at room temperature, under air and without any solvents. The top surface of the material gets converted into a continuous silver thin film and a depthwise concentration gradient of AgNPs is created in the polymer, which images the absorption profile of the actinic UV light in the reactive formulation. This specific assembling of the silver@polymer coating induces excellent reflective and conductive properties. The conductance was observed to strongly increase with increasing the exposure from 3 to 30 min due to the formation of a more and more compact metal film. This coating strategy works with a variety of substrates (textile, paper, glass, wood, plastic and stainless steel). Moreover, on flexible surfaces such as textile, the flexibility was preserved. The possibility to use this kind of nanomaterial as a printing ink, with a much lower metal concentration (3 to 5 wt.%) than concurrent inks, was also demonstrated.

Silver nanoparticles coated with thioxanthone derivative as hybrid photoinitiating systems for free radical polymerization

A new type of photoinitiator for free radical polymerization was synthesized and characterized. 2-(11-Mercaptoundecyloxy)thioxanthone (1) was anchored at the surface of silver nanoparticles (NPs), and the interaction of plasmon field generated in the immediate vicinity of Ag NPs carrying the chromophores was evaluated. The optical features and structure of the silver-initiator nanoassemblies (Ag@1) were characterized by UV-vis and fluorescence spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). TEM and XRD studies revealed the presence of ca. 5-6 nm diameter Ag NPs, and XPS also confirmed the successful anchorage of 1 at their periphery. The nanoassemblies Ag@1 were successfully used as macroinitiator for radical polymerization of acrylate monomers, triggered photochemically, to obtain Ag(0)-polyacrylate nanocomposite materials. The nanocomposite materials synthesized with the use of Ag@1 exhibit attractive possibilities for patterning the surface of thin films.

Controlling the morphology of gold nanoparticles synthesized photochemically in a polymer matrix through photonic parameters

A facile method for the preparation of gold nanoparticles (AuNPs) with various morphologies, including triangles, cubes and nanospheres into a urethane methacrylate polymer matrix, has been developed. The hybrid nanocomposites have been obtained by photoreduction of a gold precursor in the presence of a 30 wt% urethane methacrylate containing quaternary ammonium structure and 70 wt% functional monomer, carboxyl oligo-urethane dimethacrylate. The final materials contain gold nanoparticles with a morphology dependant on the reaction conditions. The influence of photonic and chemical parameters on the shape of the nanoparticles has been examined. Specific interactions between the macromolecular network and the nascent particles play an important role insofar as they control the access of metal atoms to the different crystalline planes of the growing nanoparticles, which is necessary to obtain anisotropic objects. A common mechanism for the formation of the various types of AuNPs is proposed. Coupling the intrinsic characteristics of metal nanoparticles with those of the copolymer substrate could result in materials with innovative properties.