Interaction Of Polyvinyl Alcohol Research Articles

Impacts of composition of short chain alcohols/ urea and temperature change on the interaction of polyvinyl alcohol and sodium dodecyl sulfate: Conductivity and DFT investigations

Herein, the conductivity measuring approach was used to investigate the aggregation of polyvinyl alcohol (PVA) with sodium dodecyl sulphate (NaDS) in H2O and H2O + alcohols (EtOH,1-PrOH, 2-PrOH)/ urea environments at various temperatures. The extent and nature of interaction between NaDS and PVA has been characterized from the achieved micellar parameters and energetics of the aggregation process. The micelle development has been characterized from the break point achieved in the conductivity vs. conc. of NaDS plots. At 303.15 K, the single CMC values of the NaDS + PVA mixture were decreased with increasing the amount of PVA (<0.5 % (w/w) PVA) while two CMC values were acquired at 0.5 % (w/w) PVA. The CMC values have been observed to change significantly with the concentrations of alcohols while an increasing trend in the CMC values has been detected in alcohols media above 6 % (w/w) composition. In water and aq. EtOH/urea solutions, the CMC values initially decline, reaches its lowest point, and then increases when the temperature is increased. In aq. 1-PrOH and 2-PrOH solutions, the CMC values demonstrate the enhancing fashion with increasing temperature. In all cases, negative ∆Gmo values were found, indicating spontaneous aggregation phenomena. The measurements of ∆Hmo and ∆Smo indicate that the PVA molecule interacts with NaDS through ion-dipole and hydrophobic interactions. Furthermore, compensation temperature (Tc) and intrinsic enthalpy gain (∆Hm0,*) for the studied system were measured and described with proper reasoning. In addition, the properties of complex formation and structural analysis, band gaps analysis, chemical hardness and UV-Vis spectral study of the NaDS, PVA, and NaDS + PVA mixed system with and without additive have been explored by using DFT technique.

Molecular Docking Study on Interaction of Polyvinyl Alcohol (PVA) with Group IA Bacteriocin

PVA with the molecular formula (C2H4O)n is a polymer prepared from polyvinyl acetates by replacing acetate groups with hydroxyl groups. It is a synthetic polymer with low surface tension, flexible and soft, water-soluble and cross-linkable thanks to the hydroxyl groups in its structure, biodegradable and non-toxic due to the carbon bonds in its chain. Bacteriocins are compounds of a protein nature that are ribosomally synthesized by bacteria and suitable for use as a filler in polymer matrices, especially in food packaging systems, and drug design because they are natural antimicrobial compounds sensitive to various enzymes and do not disrupt the physicochemical structure of foods while inhibiting pathogenic microorganisms. Considering their biochemical properties, they are generally divided into 4 different classes. The fact that Nisin and PVA have a structure that can serve a common purpose and have superior properties made us wonder about the interaction and bonding modes between these two. Molecular docking work is important because it prevents time, energy, and economic consumption and prepares the ground for the synthesis of new and advanced materials that are likely to be obtained in the laboratory environment. Therefore, in this study, Nisin bacteriocin (in Group IA) was chosen as the target, and a single monomer of the PVA polymer was chosen as the ligand, and the interaction between them was simulated by molecular docking method. A rational depiction of ligand-protein binding interactions was made.

Interaction of polyvinyl alcohol with cetyltrimethylammonium bromide surfactant and its effect on electrochemical property

Polymer-Surfactant mixed systems have sparked a lot of attention because of their wide range of industrial applications. In the present work, interaction features of the Polymer-Surfactant self-assembled system was computed at various ratios. The interaction between a cationic surfactant Cetyltrimethylammonium bromide (CTAB) and a water soluble polymer polyvinyl alcohol (PVA) was investigated using UV–Visible Spectroscopy, FTIR and Electrochemical investigations. At varied concentrations of PVA/CTAB, the UV–Visible spectrum of the reaction mixture was recorded. In the UV–Visible spectrum, the absorption band was observed at 272 nm. According to the UV–vis spectra the absorbance of PVA/CTAB increased at a lower concentration due to the solubility of the polymer. The ammonium salts distinctive groups were integrated on the polymer according to FTIR data. Atomic force Microscopic studies reveal that CTAB was homogeneously mixed with PVA due to interfacial interaction. The behavior of Cetyltrimethylammonium bromide and PVA mixtures has been studied electrochemically. It has shown relatively higher impedance indicating greater protection. It was revealed to be dependent on the concentrations of both polymer and surfactant.

Effects of Treatment Temperature on Properties of Starch-based Adhesives

Starch-based adhesives were developed by hydrolyzing starch with polyvinyl alcohol under alkaline and acidic conditions at various treatment temperatures. The chemical and physical structures of the corn starch and hydrolyzed starch were characterized with Fourier Transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and scanning electronic microscopy (SEM). Thermal degradation and bond strength were also evaluated. The results indicated that the bond strength of starch adhesives reached a maximum value at 40 °C. The FI-IR results showed that the amount of hydroxyl groups first increased and then decreased with increasing treatment temperature. When the treatment temperature was 55 °C the crystallinity of treated starch was the lowest and the thermal resistance also the weakest; it decreased by 10.1% and 13.6% respectively compared to untreated starch. Obvious erosion could be observed from the SEM images of treated starch. In addition, the interaction of polyvinyl alcohol (PVA) and starch also could be observed, and the results indicated that the compatibility between starch and PVA became better and better as the treated temperature was increased.

Interactions between silver nanoparticles and polyvinyl alcohol nanofibers

The interaction of polyvinylalcohol (PVA) nanofibers with silver (Ag) nanoparticles (mean diameter 8nm) has been modeled using density functional theory (DFT) calculations. The physical adsorption of PVA through the hydroxyl group, to the Ag, and its corresponding molecular orientation was compared with experimental results obtained from surface-enhanced Raman scattering (SERS) studies of the same material. A good agreement was found between the computational model of the vibrational spectrum of the adsorbate and the experimentally observed SERS. In general, aliphatic capping molecules are used to passivate the surface of Ag55 nanocrystals (55 = atomic number of Ag). In this study, a DFT simulation was employed to show binding energies and electron contour map analyses of Ag55 with PVA. Here we show that the PVA interacts with the Ag nanoparticle's surface, through the OH group, thereby contributing significantly to the increase in SERS activity.

Examination of mechanisms of interaction of polyvinyl alcohol with optical bleaching agent

The rheological and spectrophotometric characteristics of polymer compositions containing optical bleaching agent were examined. The mechanism of interaction between the components of the polymer composition was studied.

Improving Process of Surface Roughness with Super-soft Grade Resinoid Bond Wheel (2nd Report)

The surface roughness decreases down to the minimum just after start of plunge grinding with a super-soft grade resinoid bond wheel, of which bonding material is prepared by the interaction of polyvinyl alcohol and thermosetting plastics. In this paper, the grinding method with the resinoid bond wheel is investigated for the finest surface finish of workpiece, based on such minimizing phenomenon of surface roughness. Main conclusions obtained in this paper are as follows : (1) The finest surface finish is obtained by spark-out grinding operation starting just at the moment on which the surface roughness of workpiece decreases down to the minimum. (2) The surface finish by this grinding operation decreases with decreasing the initial surface roughness, but the decrease in surface roughness during the spark-out grinding process increases with increasing initial surface roughness. (3) The repetition of this grinding operation without dressing makes the surface finish smaller than that by a general grinding operation with larger depth of cut before spark-out grinding.

極軟質レジノイド砥石による表面あらさ改善過程の研究（第１報）―研削開始後の表面あらさ最小化現象―

In this paper, an improving process of surface roughness in cylindrical plunge grinding with a super-soft grade resinoid bond wheel, whose bonding material is prepared by the interaction of polyvinyl alcohol and thermosetting plastics, is discussed, analyzing the ground surface profile, the topography of acting wheel surface and so on. Main conclusions obtained in this paper are as follows: (1) Minimizing phenomenon of surface roughness in which surface roughness decreases down to the minimum after start of grinding is remarkably occurred in plunge grinding process with a super-soft grade resinoid bond wheel. And the phenomenon is useful for improving surface roughness by grinding. (2) Decrease of number of simultaneously acting cutting edge by a rapid increase of wheel wear leads to worsen the surface finish just after the point of minimizing surface roughness. (3) The number of simultaneously acting cutting edge is obtained by ground surface profile, topography of acting wheel surface and interference wheel arc length.

Studies on interaction of polyvinyl alcohol with alkaline earth metal valerates

The interaction of polyvinylalcohol (PVA) with valerates of (Sr, Ca, Mg) has been studied by conductivity measurements. The specific conductivity-soap concentration plots showed two transition points in the curves which denote the starting and completion of the interaction. The influence of salt and temperature has been examined. The salt concentration shifts the first transition point to slightly higher concentration where as the second diminishes. Temperature was found not to effect the transition points in polymersoap solutions and even the CMC of soaps were uneffected with temperature.

Effect of Urea on the Interaction of Polyvinyl Alcohol with Sodium Dodecyl Sulfate

The effect of urea on the interaction of polyvinyl alcohol (PVA) with sodium dodecyl sulfate (SDS) in aqueous solution was investigated by means of viscosity, electrophoresis, and dialysis equilibrium. In the absence of urea, the intrinsic viscosity [η], the electrophoretic mobility u, the number of effective charge Z (corresponding to the number of bound surfactant ion on PVA) of PVA-SDS complex, and the bound SDS on PVA changed depending on the SDS concentration (Cs) in solution and increased steeply from the vicinity of the first critical micelle concentration (cmc) of the surfactant. Then the first three reached maxima at the concentration corresponding to the second cmc. In the presence of urea, [η] Cs, uCs, ZCs curves and the bound SDS on PVA changed with the concentration of urea. At SDS concentrations higher than the first critical micelle concentration, the above three curves fell and the bound SDS decreased with increasing concentration of urea. These results suggest a release of the bound SDS from PVA and a contraction of the PVA-SDS complex molecule by the weakening of the electric repulsion between the surfactant ions bound on PVA.