Poly Vinyl Alcohol Derivatives Research Articles

Circularly Polarized Room Temperature Phosphorescence through Twisting‐Induced Helical Structures from Polyvinyl Alcohol‐Based Fibers Containing Hydrogen‐Bonded Dyes

AbstractRoom temperature phosphorescence (RTP) materials have garnered significant attention owing to its distinctive optical characteristics and broad range of potential applications. However, the challenge remains in producing RTP materials with more simplicity, versatility, and practicality on a large scale, particularly in achieving chiral signals within a single system. Herein, we show that a straightforward and effective combination of wet spinning and twisting technique enables continuously fabricating RTP fibers with twisting‐induced helical chirality. By leveraging the hydrogen bonding interactions between polyvinyl alcohol (PVA) and quinoline derivatives, along with the rigid microenvironment provided by PVA chains, typically, Q‐NH2@PVA fiber demonstrates outstanding phosphorescent characteristics with RTP lifetime of 1.08 s and phosphorescence quantum yield of 24.6 %, and the improved tensile strength being 1.7 times than pure PVA fiber (172±5.82 vs 100±5.65 MPa). Impressively, the transformation from RTP to circularly polarized room temperature phosphorescence (CP‐RTP) is readily achieved by imparting left‐ or right‐hand helical structure through simply twisting, enabling large‐scale production of chiral Q‐NH2@PVA fiber with dissymmetry factor of 10−2. Besides, an array of displays and encryption patterns are crafted by weaving or seaming to exemplify the promising applications of these PVA‐based fibers with outstanding adaptivity in cutting‐edge anti‐counterfeiting technology.

Circularly Polarized Room Temperature Phosphorescence through Twisting-Induced Helical Structures from Polyvinyl Alcohol-Based Fibers Containing Hydrogen-Bonded Dyes.

Room temperature phosphorescence (RTP) materials have garnered significant attention owing to its distinctive optical characteristics and broad range of potential applications. However, the challenge remains in producing RTP materials with more simplicity, versatility, and practicality on a large scale, particularly in achieving chiral signals within a single system. Herein, we show that a straightforward and effective combination of wet spinning and twisting technique enables continuously fabricating RTP fibers with twisting-induced helical chirality. By leveraging the hydrogen bonding interactions between polyvinyl alcohol (PVA) and quinoline derivatives, along with the rigid microenvironment provided by PVA chains, typically, Q-NH2@PVA fiber demonstrates outstanding phosphorescent characteristics with RTP lifetime of 1.08 s and phosphorescence quantum yield of 24.6 %, and the improved tensile strength being 1.7 times than pure PVA fiber (172±5.82 vs 100±5.65 MPa). Impressively, the transformation from RTP to circularly polarized room temperature phosphorescence (CP-RTP) is readily achieved by imparting left- or right-hand helical structure through simply twisting, enabling large-scale production of chiral Q-NH2@PVA fiber with dissymmetry factor of 10-2. Besides, an array of displays and encryption patterns are crafted by weaving or seaming to exemplify the promising applications of these PVA-based fibers with outstanding adaptivity in cutting-edge anti-counterfeiting technology.

Biodegradable Polymer Materials Based on Polyvinyl Alcohol, Starch, and Cellulose Derivatives

Biodegradable Polymer Materials Based on Polyvinyl Alcohol, Starch, and Cellulose Derivatives

Cyclic desorption based efficacy of polyvinyl alcohol-chitosan variant resins for multi heavy-metal removal

The simultaneous removal of Cu, Pb and Fe from water bodies has been targeted in this work with polyvinyl alcohol (PVA) and chitosan (low, medium, and high molecular weight) derivative and with cyclic desorption efficacy target. For a varied range of adsorbent loading (0.2–2 g L−1), initial concentration (187.7–563.1 mg L−1 for Cu, 5.2–15.6 mg L−1 for Pb, and 61.85–185.55 mg L−1 for Fe), and resin contact time (5 to 720 min), batch adsorption-desorption studies were conducted. After first adsorption-desorption cycle, the optimum absorption capacity was 6.85 mg g−1 for Pb, 243.90 mg g−1 for Cu, and 87.72 mg g−1 for Fe for the high molecular weight chitosan grafted polyvinyl alcohol resin (HCSPVA). The alternate kinetic and equilibrium models were analyzed along with the interaction mechanism between metal ions and functional groups. The cyclic desorption studies were carried out with simple eluent systems such as HCl, HNO3, H2SO4, KOH, and NaOH. The experiments revealed that the HCSPVA derivative has been an impressive, reusable, and effective sorbent for the mitigation of Pb, Fe, and Cu in complex wastewater systems. This is due to its easy synthesis, excellent adsorption capacity, quick sorption rate, and remarkable regeneration capabilities.

Homopolymeric Protein Phosphors: Overpassing the Stability Frontier of Deep‐Red Bio‐Hybrid Light‐Emitting Diodes

AbstractAlthough protein‐polymer phosphors are an emerging photon‐management filter concept for hybrid light‐emitting diodes, deep‐red‐emitting devices based on archetypal fluorescent proteins (FPs; mCherry) are still poorly performing with lifetimes <50 h under high photon‐flux excitation and ambient conditions. Here, the challenge is two‐fold: i) understanding the deactivation mechanism of red‐emitting FP‐polymer coatings and, in turn, ii) identifying the best polymer design for highly stable devices. This study first provides comprehensive photophysical/thermal/structural studies and device degradation (ambient/inert) analysis, revealing the presence of photo‐induced cis–trans isomerization and the effect of oxygen and water on the deactivation of mCherry in reference polymer coatings. Based on these findings, a new bio‐phosphor configuration using polyvinyl alcohol derivatives, in which crystallinity and amount of trapped water (stiffness and oxygen/moisture barriers) are easily controlled by the hydroxylation degree, is successfully achieved. Compared to the prior art, these devices significantly outperform the reference stability (>50‐fold enhancement), showing a brightness loss of <5% over the first 2000 h and a final device lifetime of 2600 h. Hence, this study describes a unique rationale toward designing polymers to stabilize FPs for lighting, overpassing stability frontiers in deep‐red hybrid light‐emitting diodes (HLEDs) going from hours to months.

Adsorptive removal of Zn, Fe, and Pb from Zn dominant simulated industrial wastewater solution using polyvinyl alcohol grafted chitosan variant resins

In this article, the efficacy of synthesized chitosan polyvinyl alcohol derivatives has been investigated for cyclic multi-heavy metal removal. Thereby, derivative resin revealed the combined benefits of chitosan and polyvinyl alcohol for multi-heavy metal removal from Zn dominant simulated industrial wastewater. Both FTIR and XRD results affirmed a strong interaction between PVA and chitosan. Batch adsorption studies were targeted for alternate choices of adsorbent-adsorbate ratio (0.2–2 g/L), contact period (5 to 720 min), and initial concentration (194.9–584.7 mg/L for Zn, 104.8–314.4 mg/L for Fe, and 2.65–7.95 mg/L for Pb). After the first cycle, the maximum adsorption capacity of 222.21, 135.14, and 4.02, respectively for Zn, Fe, and Pb was achieved for the high molecular weight chitosan-based polyvinyl alcohol derivative (high CSPVA). The alternate equilibrium and kinetic model based studies respectively confirmed the homogeneous and chemisorptive behavior of the adsorption. The cyclic desorption and regeneration studies inferred that the high CSPVA derivative resin has been highly efficient and useful sorbent for Zn, Fe, and Pb removal. Thereby, the investigations assure confidence in the relevance of the mentioned resin for real scenarios that demand the treatment of industrial multi-heavy metal containing wastewater systems.

Interaction between an Oxidized Fraction of Polyvinyl Alcohol and Uracil Derivatives in Aqueous Solutions

Interaction between an Oxidized Fraction of Polyvinyl Alcohol and Uracil Derivatives in Aqueous Solutions

Simple synthesis of conjugated polyvinyl alcohol derivative-modified ZnFe2O4 nanoparticles with higher photocatalytic efficiency

Conjugated polyvinyl alcohol derivative (CPVA)/ZnFe2O4 nanocomposite was synthesized by a simple liquid-solid phase mixing and thermal dehydration/conjugation method. The CPVA/ZnFe2O4 nanocomposite showed not only stronger photocatalytic activity than ZnFe2O4 nanoparticles and previously reported MgFe2O4/CPVC and ZnFe2O4/CPVC photocatalysts (specifically, the photocatalytic activity of CPVA/ZnFe2O4 was 3 times that of ZnFe2O4, and 300 mg CPVA/ZnFe2O4 can achieve almost complete reduction of the Cr(VI) in 300 mL 50 mg/L K2Cr2O7 aqueous solution after 300 min visible-light irradiation), but also remarkable reuse performance in the visible-light-activated reduction of aqueous Cr(VI). Furthermore, the CPVA/ZnFe2O4 nanocomposite can be separated from the solution by magnetic attraction. The elevated photocatalytic activity of CPVA/ZnFe2O4 nanocomposite was experimentally found to be due to its more efficient transfer and separation of photo-induced charges. The proposed modification of ZnFe2O4 using CPVA is effective, economical, and environmental friendly, and the CPVA/ZnFe2O4 nanocomposite photocatalyst has potential in utilizing sunlight for treating Cr(VI)-polluted water.

Deformation‐induced bonding of polymer films below the glass transition temperature

AbstractBonding between polymers through interdiffusion of macromolecules is a well‐known mechanism of polymer adhesion. A new polymer bonding mechanism in the solid state, taking place at ambient temperatures well below the glass transition value (Tg), has been recently reported; in this mechanism, bulk plastic compression of polymer films held in contact led to adhesion over timescales of the order of a fraction of a second. In this study, we prepared various blends of plasticized polymer films with desirable ductility from amorphous and semicrystalline powders of hydroxypropyl methylcellulose and polyvinyl alcohol derivatives; then, we observed the bonding of these polymers at ambient temperatures, up to 80 K below Tg, purely through mechanical deformation. The deformation‐induced bonding of the polymer films studied in this work led to interfacial fracture toughnesses in the range of 1.0–21.0 J/m2 when bulk plastic strains between 3% and 30% were imposed across the films. Scanning electron microscopy observation of the debonded interfaces also confirmed that bonding was caused by deformation‐induced macromolecular mobilization and interpenetration. These results expand the range of applicability of sub‐Tg, solid‐state, deformation‐induced bonding processes.

Synthesis, Characterization, and Antimicrobial Activity of CoO Nanoparticles from a Co (II) Complex Derived from Polyvinyl Alcohol and Aminobenzoic Acid Derivative.

Cobalt oxide nanoparticles (CoO NPs) were synthesized by the calcination method from the Co (II) complex which has the formula [Co(PVA)(P-ABA)(H2O)3], PVA = polyvinyl alcohol, and P-ABA = para-aminobenzoic acid. The calcination temperature was 550°C, and the products were characterized by element analysis, thermal analyses (TGA and DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), UV-Vis spectra, and scanning electron microscopy (SEM) techniques. The kinetic and thermodynamic parameters (∆H ∗, ∆G ∗, and ∆S ∗) for the cobalt (II) complex are calculated. The charges been carried by the atoms cause dipole moment 10.53 and 3.84 debye and total energy 11.04 × 102 and 24.80 × 102k Cal mol−1 for the Co (II) complex and cobalt oxide, respectively. X-ray diffraction confirmed that the resulting oxide was pure single-crystalline CoO nanoparticles. Scanning electron microscopy indicating that the crystallite size of cobalt oxide nanocrystals was in the range of 36–54 nm. Finally, the antimicrobial activity of cobalt oxide nanoparticles was evaluated using four bacterial strains and one fungal strain. Two strains of Gram-positive cocci (Staphylococcus aureus and Enterococcus faecalis), two strains of Gram-negative bacilli (Escherichia coli and Pseudomonas aeruginosa), and one strain of yeast such as fungi (Candida albicans) were used in this study.

High-efficiency visible-light-driven Ag3PO4 photocatalysts modified by conjugated polyvinyl alcohol derivatives

Due to its high-efficiency Ag3PO4 serves as a photocatalyst driven by visible light, which in this study was prepared through surface modification using a small amount of conjugated polyvinyl alcohol derivatives (CDPVA) via a simple chemisorption and heat treatment approach. The as-prepared CDPVA/Ag3PO4 composite photocatalysts were characterized via a varieties of analyses. The photocatalytic performance of the as-prepared composite photocatalysts was estimated through the photodegradation of methyl orange solution and the photoreduction of aqueous Cr(VI) solution with visible light. Results showed that the introduction of a trivial part of CDPVA on the surface of Ag3PO4 particles did not change their crystallinity and sizes but significantly reduced the aggregation of particles, strengthened the visible-light absorbance, and produced a more efficient separation of the photogenerated electron–hole pairs in the investigated composite photocatalysts. The visible-light photocatalysis of the composites exhibited a higher stability and activity than pure Ag3PO4. The visible-light photocatalysis of the composites exhibited an initial rise and a later reduction with increase in CDPVA content in the composites and heat treatment temperature and time. The synthetic photocatalysts exhibited the strongest visible-light photocatalysis when the CDPVA to Ag3PO4 mass ratio, heat treatment temperature, and treatment time were 1: 8000, 180 °C, and 1 h respectively. The mechanism for visible-light photocatalysis of the CDPVA/Ag3PO4 composites was also investigated. The solubility of Ag3PO4 in water environment was significantly decreased by the surface modification of CDPVA.

Dispersed Association of Single-Component Short-Alkyl Chains toward Thermally Programmable and Malleable Multiple-Shape Hydrogel.

In pursuit of intelligent hydrogel-based devices, it is imperative to concurrently enhance the shape programmability and customization of hydrogels in order to realize sophisticated actuation and implantation. Until now, multiple temporary shapeshifting of hydrogels has required either multiple external stimuli or distinct thermal-transition phases. In addition, reprocessing the permanent shape of hydrogel mostly relies on the change in their components. These complex prerequisites present challenges to programmability and customization of application-related shapes for hydrogels. This paper reports a type of thermally programmable and malleable multiple-shape hydrogel. The network of this hydrogel is solely composed of a type of polyvinyl alcohol derivative, which is synthesized by substituting hydroxyl groups of polyvinyl alcohol with single-component octyl chains. Through water-vapor exchange and heating in water, these single-component octyl side chains form dispersed clusters with a large strength gradient. Such broadly dispersed clusters serve as switchable segments and dynamic net-points to orthotopically offer multiple (e.g., quintuple) temporary shapes and editable permanent shapes, respectively, thereby realizing sophisticated and designed shape changes. This hydrogel system can act as a smart device for on-demand bidirectional twining around a 1D substrate. Such a capability potentially enables the self-mounting and self-detaching behavior of soft devices on tissues with minimal invasion.

Preparation of SnO2/conjugated polyvinyl alcohol derivative nanohybrid with good performance in visible light-induced photocatalytic reduction of Cr(VI)

A new visible light-responsive SnO2/conjugated polyvinyl alcohol derivative (CPVA) nanohybrid photocatalyst was prepared by an easy-to-implement three-step method, using low cost and easily accessible SnCl4·5H2O, PVA and H2O as the source materials. The photocatalytic properties of the as-prepared SnO2/CPVA nanohybrid were examined through the reduction of aqueous Cr(VI) in the presence of citric acid and visible light (λ > 420 nm). The compositional and structural analysis of SnO2/CPVA nanohybrid after the recycle stability test was also performed. The photodegradation efficiency of Cr(VI) using SnO2/CPVA nanohybrid and other reported visible light-responsive photocatalysts (g-C3N4 and ZnFe2O4/CPVC nanocomposite) were compared. Besides, the effects of the solution pH and different water matrices (including black chromium electroplating solution, industrial cooling water, yellow sea water, and tap water) on the efficiency of photocatalytic reduction of Cr(VI) by SnO2/CPVA nanohybrid were also investigated. The results manifested that the as-prepared SnO2/CPVA nanohybrid had both high activity and good stability in photocatalytic reduction of aqueous Cr(VI) under visible light irradiation. According to the results of photoabsorption, photoluminescence, transient photocurrent response, electrochemical impedance, and Mott-Schottky characterization, it was deduced that the notable visible light-activated photocatalysis of SnO2/CPVA nanohybrid may originate from its prominent visible light-absorbing ability and the efficient electron transfer from CPVA to SnO2 (which results in the efficient separation of photoinduced charge carriers of CPVA as well as the sensitization of SnO2).

Multi-responsive, bidirectional, and large deformation bending actuators based on borax cross-linked polyvinyl alcohol derivative hydrogel

N-Alky-substituted carbamate-modified PVA as a layer material to enable multi-responsive, bidirectional and large deformation actuation.

Novel polyvinyl alcohol derivatives as scaffolds for hepatocyte culture and hepatotoxicity of drugs

Novel polyvinyl alcohol derivatives as scaffolds for hepatocyte culture and hepatotoxicity of drugs

Control of swelling properties of polyvinyl alcohol/hyaluronic acid hydrogels for the encapsulation of chondrocyte cells

ABSTRACTHydrogel scaffolds for tissue engineering are important biomaterials. The target in this study was to prepare polyvinyl alcohol/hyaluronic acid hydrogels for the encapsulation of chondrocyte cells by a simple cross‐linking reaction. Control of the swelling properties and morphology of the hydrogels for cultivation of chondrocytes was studied. The hydrogels were prepared from polyvinyl alcohol and hyaluronic acid derivatives bearing primary amine and aldehyde functionalities, respectively. The formation of the hydrogel upon mixing the aqueous solutions of the polymer derivatives took place at room temperature in a few seconds. The swelling properties of the hydrogels were found to depend on the polymer concentration and degree of substitution of the modified polymers. Scanning electron microscopy studies showed that the hydrogels had a suitable porous morphology for cell encapsulation. Furthermore, in vitro cell viability tests with the hydrogels showed no cytotoxicity for chondrocytes and that the cells grew well in the hydrogel scaffolds. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42272.

High Mn2+ Uptake by a New Polyvinyl Alcohol Derivative: Isotherm Model Analysis

The transformation of Polyvinyl alcohol (PVA) into poly(vinyl phenylthionecarbamate) (PVA-PT) was upgraded to 35 g with 45% yield and 90% conversion degree. PVA-PT has shown high uptakes (93-96%) towards Mn2+ > Cu2+ > Cd2+ after 4 hours stirring at 20°C in a batch procedure, towards 31-1600 mg/L concentration range. The material and its metal ion adducts were characterized by gravimetric analysis, IR, Raman, and SEM/EDS. An experimental design was applied to evaluate the influence of parameters on the Mn2+ removal efficiency by PVA-PT. The best results were achieved after 240 min, at 20°C and concentrations higher than 187 mg/L. The 20°C sorption isotherms were recorded for the PVA-PT/Mn2+ system at different particle sizes and dosages. The best experimental sorption capacity (qe = 343.76 mg/g) was reached at the lowest dose (0.05 g in 10 mL solution) and the highest concentration (1809.82 mg/L). Data fit Freundlich isotherm model (R2 = 0.9462, KF = 0.8625, N = 0.8271), indicative of a moderate affinity interaction PVA-PT/Mn+2. The kinetic isotherm models demonstrate chemisorption and bulk diffusion-controlled absorption into the material after 7 min.

A review of polyvinyl alcohol derivatives: Promising materials for pharmaceutical and biomedical applications

In recent years, a technological breakthrough in the pharmaceutical and biomedical fields have been reflected in the development of more complex, safe and effective dosage forms to improve the administration, delivery, disposition and stability of drugs, as well as at creating more biocompatible and biodegradable materials. As a result, modified release devices and functional coatings which improve the effectiveness and efficacy of drugs have been generated. This advancement has been achieved by physical or chemical modification of natural or semisynthetic polymers which stabilize and protect drugs against harsh environmental factors. Therefore, the development of novel excipients with a high functionality and robustness has become an important quest. Among these materials, polyvinyl alcohol is one of the most versatile and biocompatible, since by chemical or physical modification its properties are modulated, improving drug stability, drug targeting, and ensures patient compliance. Freezing-thawing cycles, heat treatment and formation of composites are the most significant physical modifications to improve the performance of polyvinyl alcohol. On the other hand, the chemical modifications by cross-linking with aldehydes, carboxylic acids, sodium tetraborate, epichlorohydrin have enhanced the physical and mechanical properties, such as the oil sorption ability, oxygen and waterproof characteristics, mechanical strength, drug diffusion and rate of swelling. Key words: Polyvinyl alcohol, composites, crosslinking, pharmaceutical and biomedical applications.

Polyvinyl alcohol-based hydrogel dressing gellable on-wound via a co-enzymatic reaction triggered by glucose in the wound exudate.

Glucose is a common component of body fluids. We describe a hydrogel wound dressing that can be obtained by pouring an aqueous solution of a polyvinyl alcohol derivative possessing phenolic hydroxyl moieties (PVA-Ph), containing glucose oxidase (GOx) and horseradish peroxidase (HRP), onto a wound. The in situ hydrogelation progresses through GOx-catalysed hydrogen peroxide (H2O2) generation from glucose in the wound exudate and HRP-catalysed cross-linking between phenolic hydroxyl moieties in PVA-Ph by consuming the H2O2. The potency as a wound dressing is demonstrated by experiments which reveal that the existence of the conditions inducing hydrogelation within 20 s at normal blood glucose concentration, the durability of the resultant hydrogels to compression and stretching, and the faster closure of full-thickness wounds created on rats treated with the in situ formed hydrogel than those treated by a commercially available hydrogel dressing.

Cooperative use of cytochrome cd1 nitrite reductase and its redox partner cytochrome c552 to improve the selectivity of nitrite biosensing

In this work, a novel enzymatic biosensor for determination of nitrites constructed on an electrochemical transducing platform is proposed. The sensor is based on cytochrome- cd 1 (cyt- cd 1) nitrite reductase from Marinobacter hydrocarbonoclasticus strain 617 as biological recognition element, and its putative physiological redox partner cytochrome- c 552 (cyt- c 552), as electron mediator. The proteins were co-immobilized using a photopolymerizable polyvinyl alcohol (PVA) derivative, onto carbon paste screen printed electrodes (CPSPEs); the optimal modification conditions were 100 μM cyt- cd 1/100 μM cyt- c 552 and 50% PVA, after a 48 h polymerization time. Electrochemical characterization of the mediator was carried out by cyclic voltammetry. The one-electron exchange between cyt- c 552 and the working electrode is a quasi-reversible process, without mass transport limitations. The formal potential of the mediator is 254 ± 2 mV vs NHE and the intermolecular electron transfer rate constant between cytochromes c 552 and cd 1 is 9.9 × 10 3 M −1 s −1. The analytical parameters of the biosensor response to nitrite as assessed by amperometric measurements were: linear range from 10 to 200 μM; detection and quantification limits of 7 and 24 μM, respectively; sensitivity of 2.49 ± 0.08 A mol −1 cm 2 μM −1. Catalytic profiles in the presence of possible interfering species were also investigated. The interference from competitive enzymatic reduction of dissolved oxygen could be overcome by tuning the cyclic voltammograms for faster sweep rates.