No abstract

Cr2O3-SnO2 heterojunction nanocomposites were prepared via chemical precipitation method. The prepared samples were characterized by X-ray diffraction (XRD), Transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectra and Field Emission Electron Microscopy (FESEM). The XRD spectrum confirms the presence of both tetragonal rutile SnO2 and rhombohedral corundum Cr2O3 structure. Further investigation into the gas sensing performances of the prepared Cr2O3-SnO2 nanocomposites exhibited an enhanced sensitivity towards VOPs such as isopropanol, acetone, ethanol and formaldehyde. Especially, isopropanol vapor sensor shows excellent sensitivity at an operating temperature of 100 °C. The highest sensitivity for Cr2O3-SnO2 heterojunction nanocomposites indicate that these materials can be a good candidate for the production of high-performance isopropanol sensors.

No abstract

No abstract

Polymer nanocomposites (PNC) include a copolymer or polymer which has nanoparticles dispersed in the polymer matrix at the nano-level. One of the most common types of polymer nanocomposites contain smectic clays as the nanoparticles. These clay minerals increase the mechanical properties of standard polymers and improve barrier properties. For optimum barrier properties, Layer-by-Layer assembly (LbL) is one of the most effective methods for depositing thin films. LbL methods however, are quite tedious and produce large quantities of waste. A newly discovered phenomenon of self-assembled polymer nanocomposites utilizes entropic forces to drive the assembly to spontaneously form a larger nanostructured film. This approach allows polymers and nanoparticles with high particle loadings to be mixed, and create the super gas barrier films. We have developed a coating technique which can be employed to make self-assembled gas barrier films via inkjet printing. This technique is industrially scalable and efficient. This is because it does not need any rinsing step and drying steps as required in LbL. The influence of different polymers Polyvinylpyrrolidone (PVP) and Poly (acrylic acid) PAA with Montmorillonite (MMT) nanoclay solutions on Polyethylene terephthalate (PET) substrate is examined to study their effectiveness as a gas barrier film. The results showing the excellent oxygen barrier behavior of a combination of PVP and MMT Nano clay nanocomposite with high transparency. These high barrier gas nanocomposite films are good candidates for a variety of food packaging applications.