The Surface Structure and Thermal Properties of Novel Polymer Composite Films Based on Partially Phosphorylated Poly(vinyl alcohol) with Aluminum Phosphate

Partially phosphorylated polyvinyl alcohol (PPVA) with aluminum phosphate (ALPO4) composites was synthesized by solution casting technique to produce (PPVA)100-y-(ALPO4)y (y = 0, 1, and 2). The surface structure and thermal properties of the films were characterized using Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA). The results showed that the films have higher thermal stability with strong bonding between PPVA and ALPO4

Synthesis and characterization of partially phosphorylated poly (Vinyl Alcohol) – aluminum phosphate (PPVA – AlPO4) nanocomposite / Asmalina Mohamed Saat

Partially phosphorylated polyvinyl alcohol - aluminum phosphate (PPVA-AlPO4) composite were synthesized through continuous stirring and condensation at 80 °C. Interaction of pure polyvinyl alcohol (PVA) with phosphoric acid (PA) produced partially phosphorylated poly vinyl alcohol (PPVA) and the addition of aluminum (Al) source produces a PPVA-AlPO4 composite. Fourier Transform Infrared (FTIR) and Raman spectra of PPVA confirmed the phosphate group in PPVA-AlPO4 composite. The phosphate group had bonded with aluminum at C-O-P- AlPO4, O-P-O- AlPO4 and also OH-Al. The optical properties of these PPVA and PPVA-AlPO4 nanocomposite samples were examined by UV-visible and photoluminescence (PL) spectroscopy. UV analysis of PPVA shows single peak at 274 nm while in PPVA-AlPO4, the peak was shifted to lower wavenumber of 208 nm. PL spectra of PPVA-AlPO4 shows broad peak at range of 304-371, 450-550 and 560-700 nm. This confirmed that the phosphate group in PPVA created bonding with aluminum. Transgravimetric (TGA) analysis shows that the weight residue of PPVA-AlPO4 composite was higher than PPVA and PVA. X-ray diffraction (XRD) pattern of PVA shows a single peak at angle of 20°. However, the peak become broadened as PA added. Meanwhile, the addition of aluminum source produced multiple peaks referring to the multiple phases of AlPO4 in the nanocomposite. Field Emission Scanning Electron Microscopy (FESEM) confirmed the existence of multiple geometrical phases and nanosize of spherical particles. The influence of important synthesis parameters such as, effect of PPVA, effect of aluminum sources, pH and crystallization time are also studied

Effect of Phosphoric Acid Concentration on the Optical Properties of Partially Phosphorylated PVA Complexes

Partially phosphorylated polyvinyl alcohol (PPVA) films were prepared at five mole ratios of phosphoric acid (PA) using solution casting technique. The optical properties of the PPVA films were examined using UV-visible (UV) and photoluminescence (PL) spectroscopy. The UV absorption spectra reveal that the absorption peaks are blue-shifted with an increase in PA concentration added to the pure PVA. The PL spectra show the presence of peaks which are characteristic of isotactic (389–398, 460–462 nm), syndiotactic (418–420 nm), and atactic (440–446 nm) configurations of the PPVA. The results also show the peak of O–P–O bonding at a wavelength range of 481–489 nm

Mechanical Performance and Corrosion Behaviour of Diffusion-Bonded A5083 Aluminium and A36 Mild Steel with Gallium Interlayer

This article investigated the mechanical performance and corrosion behaviour of a diffusion-bonded A5083 aluminium/A36 mild steel dissimilar joint with a Gallium (Ga) interlayer. The bonding parameters were the bonding temperature (525 and 550 °C), holding time (60 and 120 min) and surface roughness (800 and 1200 grit). Property characterisation was achieved using Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) analysis, Vickers microhardness tester, Izod impact tester and potentiodynamic polarisation testing. The results revealed that the significance of the bonding parameters was in the order bonding temperature > surface roughness > holding time. Increasing the bonding temperature resulted in an increase in the impact strength and a corresponding reduction in the corrosion rate and microhardness. However, increasing the grit size decreased the microhardness and a corresponding increase in the impact strength and corrosion rate. The impact strength and corrosion rate decreased with the increasing holding time while the microhardness followed a reverse trend. It was also discovered that incorporating the Ga interlayer resulted in a 67.9% improvement in the degradation rate

Raman spectroscopy and FTIR spectroscopy studies of Mn-doped CdSe QDs at different particles size

In this paper, we exclusively report on raman spectroscopy and fourier-transform infrared (FTIR) spectroscopy results and analysis of zinc blende manganese-doped cadmium selenide quantum dots (Mn-doped CdSe QDs) that synthesized using inverse Micelle technique with physical size ranging from 3 to 14 nm. Two significant peaks were observed correspond to the raman scattering by longitudinal optical (LO) of phonon and its first overtone (2LO) which located near ∼ 200 and 400 cm−1 under an exposure of 532 nm incident laser The role of oleic acid acid as a surfactant and capping agent shows in FTIR spectra

Optical structure modification induced by lattice strain in Mn-doped CdSe QDs

Narrow size distribution manganese-doped cadmium selenide quantum dots (Mn-doped CdSe QDs) successfully synthesized using inverse Micelle technique with organic solvent and surfactant possesses zinc blende structure with physical size ranging from 3 to 14 nm and crystallite size 2.46–5.46 nm. Mn-doped CdSe QDs observed to growth larger QDs compared to pure CdSe QDs at significantly same reaction times. The lattice parameter compressed with QDs sizes growth due to the introduction of lattice strain provoked by the incorporation of Mn atoms into CdSe QDs lattice. The Mn-doped CdSe QDs shows a slight blue-shift on absorption and emission spectra's compared to pure CdSe even though is possessed larger QDs. The band gap structure modification prominently affected by the lattice strain were transition of Stoke's, Rayleigh to anti-Stoke’s shifts observed as the Mn-doped CdSe QDs size growth. The typical red-shift of absorption and emission wavelength observed with growth of QDs sizes. The role of oleic acid as a surfactant and capping agent shows in FTIR spectra. The lattice strain tailored the binding energy between the ion prominently on the surface of the QDs with growth of QDs sizes

Influence of Reaction pH towards the Physicochemical Characteristics of Phosphorylated Polyvinyl Alcohol-Aluminum Phosphate Nanocomposite

The present study deals with the formation of a phosphorylated polyvinyl alcohol (PPVA)-Aluminum Phosphate (AlPO4) nanocomposite, changing the pH solution under the two-step process involving the phosphorylation of polyvinyl alcohol (PVA) followed by the conjugation with AlPO4. The composite was formed by varying the pH of the solution in the range of 7–12 and the reflected changes in the product’s morphology, crystallinity, surface nature, thermal stability, etc. were recorded using FESEM, XRD, FTIR, UV-Vis spectroscopy, TGA, etc. From the analysis, it was found that the particles formed with two different sizes of the probed pH, and at pH 10 they were homogeneously distributed. In addition, the morphology of the PPVA-AlPO4 composite also seems to be altered with respect to the pH and this is due to the differences in the amount of H+ and OH− anions. Thus, from the overall analysis, it can be indicated that pH 10 needs to be maintained for the formation of a spherical shape and uniformly distributed PPVA-AlPO4 nanocomposite