This study reports the immobilization of a new lipase isolated from oleaginous seeds of Pachira aquatica, using beads of calcium alginate (Alg) and poly(vinyl alcohol) (PVA). We evaluated the morphology, number of cycles of reuse, optimum temperature, and temperature stability of both immobilization methods compared to the free enzyme. The immobilized enzymes were more stable than the free enzy...

The preparation of a high-strength and highly transparent nacre-like nanocomposite via layer-by-layer assembly technique from poly(vinyl alcohol) (PVA) and Na+-montmorillonite clay nanosheets is reported in this article. We show that a high density of weak bonding interactions between the polymer and the clay particles: hydrogen, dipole-induced dipole, and van der Waals undergoing break-reform ...

In the current study, black tea leaves extract solution (TES) as a new green technique is used to fabricate metal-polyphenols complexes (X-polyphenols complex; X= Cu+2, Ce+3, and Cd+2). The metal-complexes are integrated with poly (vinyl alcohol) (PVA) prepare PVA composite films. electrical properties of pure composites characterized using electrochemical impedance spectroscopy (EIS) m...

This research investigated the generation of passively Q-switched erbium (Er)-doped fibre laser using silver nanoparticles/poly (vinyl alcohol) (Ag/PVA) as a saturable absorber (SA). The Ag nanoparticles were synthesised via chemical reduction technique. Ag/PVA film based SA was fabricated by blending powder into PVA suspension, then left to dry at ambient develop free-standing film. Next, sand...

Dedicated to Professor Gregorio Weber in the occasion of his 80th birthday It was found by investigating dichroism and emission anisotropy in the case of oneand two-photon excitation of Hoechst 33342 [bis-benzimide,2,5'-bi-lH-benzimidazole, 2'-(4-ethoxyphenyl)-5-5(4methyl-l-piperazinyl)] in stretched poly(vinyl alcohol) (PVA) films, that the absorption and fluorescence transition moments lie al...

Films of pure poly(vinyl alcohol) (PVA) and samples doped with di€erent concentrations of heptahydrated ferrous sulphate were prepared using a casting method. Mechanical and relaxation properties were measured before and after irradiation. The modulus of elasticity, yield strength, tensile strength ductility and relaxation time were produced from true stress±true strain and stress relaxation me...

Terahertz (THz) conductivity of single walled carbon nanotube (SWNT)/poly-vinyl alcohol (PVA) composites has been studied in the frequency window of 0.3-2.0 THz. It is found that conductivity of these samples can be efficiently tuned by changing the length of the SWNTs and also the SWNT weight fraction. For the highest weight fraction at a frequency of 1 THz, longer SWNT sample (average length ...

Bacterial cellulose (BC) grown from a culture medium in the presence of water-soluble poly(vinyl alcohol) (PVA) produced an assemblage that was used as precursor for the synthesis of biocompatible nanocomposites. Physical crosslinking via cyclic freezing and thawing of the formed hydrogel facilitated retention of PVA matrix upon composite separation and purification. The composites displayed a ...

Nanoparticle alloys of platinum (Pt) and another metal are desirable for catalytic applications to decrease the loading of the precious metal and alter the physiochemical structure of these materials to enhance their catalytic properties. This study explores the potential of producing gold and platinum nanoparticle alloys using a microplasma reduction technique. In this process, metal salt prec...

Wound dressing is an artificial skin that can meet the requirements such as higher vapor or gas permeation and protection of wound from infection and dehydration. Poly (vinyl alcohol) (PVA) hydrogel is one of the well-known polymer gel that due to its good biocompatibility, hydrophilicity and capability of swell in water or biological fluids has been used in several biomedical and pharmaceutica...