Displaying publications 61 - 80 of 103 in total

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  1. Liew MS, Aswin M, Danyaro KU, Mohammed BS, Al-Yacouby AM
    Materials (Basel), 2020 May 26;13(11).
    PMID: 32466366 DOI: 10.3390/ma13112428
    In relation to the use of retrofit materials on damaged constructions, application on earthquake-resistant buildings, and for the strengthening and rehabilitation on weakened regions, there is a need for a more superior material than concrete. Application sites include beam-column joints, corbels, link-slabs, deep beams, support regions and dapped-end areas. Fiber reinforced engineered cementitious composites (FR-ECC) can address this issue, because FR-ECC is one of the composite materials that has high strength, ductility and durability. In order to develop FR-ECC, this study was done to investigate the effect of adding quartz powder on the compressive strength capacity and properties of FR-ECC through the use of polyvinyl alcohol (PVA) and steel fibers. The volume fraction of fiber was set to 0%-2%. To support the friendly environment, FR-ECC uses by-product materials such as fly ash and silica fume, with a cement content less than 600 kg/m3. In terms of the experimental investigation on FR-ECC, this work conducted the fresh property tests showing that PVA fibers have quite an influence on ECC workability, due to their hydrophilic behavior. By adjusting the superplasticizer (SP) content, the consistency and high workability of the ECC mixes have been achieved and maintained. The test results indicated that the PVA and steel fibers-based ECC mixes can be classified as self-compacting composites and high early compressive strength composites. Significantly, addition of quartz powder into the ECC mixes increased the compressive strength ratio of the ECC samples up to 1.0747. Furthermore, the steel fiber-based ECC samples exhibited greater compressive strength than the PVA fibers-based ECC samples with the strength ratio of 1.1760. Due to effect of the pozzolanic reaction, the fibers dispersion and orientation in the fresh ECC mixes, so that the cementitious matrices provided the high strength on the FR-ECC samples. During the compression loading, the bulging effect always occurred before the failures of the fibers-based ECC samples. No spalling occurred at the time of rupture and the collapse occurred slowly. Thus, FR-ECC has provided unique characteristics, which will reduce the high cost of maintenance.
    Matched MeSH terms: Polyvinyl Alcohol
  2. Brza MA, B Aziz S, Anuar H, Dannoun EMA, Ali F, Abdulwahid RT, et al.
    Polymers (Basel), 2020 Aug 23;12(9).
    PMID: 32842522 DOI: 10.3390/polym12091896
    In the present work, a novel polymer composite electrolytes (PCEs) based on poly(vinyl alcohol) (PVA): ammonium thiocyanate (NH4SCN): Cd(II)-complex plasticized with glycerol (Gly) are prepared by solution cast technique. The film structure was examined by XRD and FTIR routes. The utmost ambient temperature DC ionic conductivity (σDC) of 2.01 × 10-3 S cm-1 is achieved. The film morphology was studied by field emission scanning electron microscopy (FESEM). The trend of σDC is further confirmed with investigation of dielectric properties. Transference numbers of ions (tion) and electrons (tel) are specified to be 0.96 and 0.04, respectively. Linear sweep voltammetry (LSV) displayed that the PCE potential window is 2.1 V. The desired mixture of activated carbon (AC) and carbon black was used to fabricate the electrodes of the EDLC. Cyclic voltammetry (CV) was carried out by sandwiching the PCEs between two carbon-based electrodes, and it revealed an almost rectangular shape. The EDLC exhibited specific capacitance, energy density, and equivalent series resistance with average of 160.07F/g, 18.01Wh/kg, and 51.05Ω, respectively, within 450 cycles. The EDLC demonstrated the initial power density as 4.065 × 103 W/Kg.
    Matched MeSH terms: Polyvinyl Alcohol
  3. Mehmood A, Mubarak NM, Khalid M, Jagadish P, Walvekar R, Abdullah EC
    Sci Rep, 2020 11 18;10(1):20106.
    PMID: 33208815 DOI: 10.1038/s41598-020-77139-2
    Strain sensors in the form of buckypaper (BP) infiltrated with various polymers are considered a viable option for strain sensor applications such as structural health monitoring and human motion detection. Graphene has outstanding properties in terms of strength, heat and current conduction, optics, and many more. However, graphene in the form of BP has not been considered earlier for strain sensing applications. In this work, graphene-based BP infiltrated with polyvinyl alcohol (PVA) was synthesized by vacuum filtration technique and polymer intercalation. First, Graphene oxide (GO) was prepared via treatment with sulphuric acid and nitric acid. Whereas, to obtain high-quality BP, GO was sonicated in ethanol for 20 min with sonication intensity of 60%. FTIR studies confirmed the oxygenated groups on the surface of GO while the dispersion characteristics were validated using zeta potential analysis. The nanocomposite was synthesized by varying BP and PVA concentrations. Mechanical and electrical properties were measured using a computerized tensile testing machine, two probe method, and hall effect, respectively. The electrical conducting properties of the nanocomposites decreased with increasing PVA content; likewise, electron mobility also decreased while electrical resistance increased. The optimization study reports the highest mechanical properties such as tensile strength, Young's Modulus, and elongation at break of 200.55 MPa, 6.59 GPa, and 6.79%, respectively. Finally, electrochemical testing in a strain range of ε ~ 4% also testifies superior strain sensing properties of 60 wt% graphene BP/PVA with a demonstration of repeatability, accuracy, and preciseness for five loading and unloading cycles with a gauge factor of 1.33. Thus, results prove the usefulness of the nanocomposite for commercial and industrial applications.
    Matched MeSH terms: Polyvinyl Alcohol
  4. Hanini ‘Aina, Nik Nur Shamiha Nik Dzulkefli, Mohamed Rasny, Samer Al-Dhalli, Mohd Nizam, Eddy Yusuf, et al.
    MyJurnal
    The composition of ophthalmic preparation is administered topically to the eye in the form of a solution, suspension, ointment, gel or foam for the purpose of treating eye disease. Virgin Coconut Oil (VCO) has been one of the desired ingredients of choice, as its benefits as functional food oil is known among the public. The uniqueness of coconut oil is its fats and oils that contain the highest percentage of medium-chain fatty acids (MCFA), which have antimicrobial properties, such as lauric acid and capric acid. This study aimed to evaluate the antimicrobial effects of eye drop containing a different VCO concentration using the Kirby-Bauer test. The formulation of eye drop had 1.5%, 2% and 3% amount of virgin coconut oil, which was later added with all basic materials needed for eye drop. The samples were evaluated for its zone of inhibition (ZOI). The antimicrobial effects of eye drop formulation that contains 3% of VCO (F3) against Streptococcus pneumonia were similar with all control products (Eye Glo, Pred Forte, Cationorm), and antimicrobial effects of F3 against Staphylococcus aureus are better than Cationorm. It is noticeable that the higher the VCO content in the formulation, the better the antimicrobial effects of the eye drop. In conclusion, VCO possesses moisture, anti-inflammation, better anti-microbial properties, and it could be further formulated as a stable eye drop emulsion.
    Matched MeSH terms: Polyvinyl Alcohol
  5. Habiba U, Afifi AM, Salleh A, Ang BC
    J Hazard Mater, 2017 Jan 15;322(Pt A):182-194.
    PMID: 27436300 DOI: 10.1016/j.jhazmat.2016.06.028
    In this study, chitosan/polyvinyl alcohol (PVA)/zeolite nanofibrous composite membrane was fabricated via electrospinning. First, crude chitosan was hydrolyzed with NaOH for 24h. Afterward, hydrolyzed chitosan solution was blended with aqueous PVA solution in different weight ratios. Morphological analysis of chitosan/PVA electrospun nanofiber showed a defect-free nanofiber material with 50:50 weight ratio of chitosan/PVA. Subsequently, 1wt.% of zeolite was added to this blended solution of 50:50 chitosan/PVA. The resulting nanofiber was characterized with field emission scanning electron microscopy, X-Ray diffraction, Fourier transform infrared spectroscopy, swelling test, and adsorption test. Fine, bead-free nanofiber with homogeneous nanofiber was electrospun. The resulting membrane was stable in distilled water, acidic, and basic media in 20 days. Moreover, the adsorption ability of nanofibrous membrane was studied over Cr (VI), Fe (III), and Ni (II) ions using Langmuir isotherm. Kinetic parameters were estimated using the Lagergren first-order, pseudo-second-order, and intraparticle diffusion kinetic models. Kinetic study showed that adsorption rate was high. However, the resulting nanofiber membrane showed less adsorption capacity at high concentration. The adsorption capacity of nanofiber was unaltered after five recycling runs, which indicated the reusability of chitosan/PVA/zeolite nanofibrous membrane. Therefore, chitosan/PVA/zeolite nanofiber can be a useful material for water treatment at moderate concentration of heavy metals.
    Matched MeSH terms: Polyvinyl Alcohol
  6. Lee, Tin Sin, Wan Aizan Wan Abdul Rahman, Abdul Razak Rahman, Noor Azian Morad, Mohd Shahrul Nizam Salleh
    MyJurnal
    The specific heats (Csp) of neat polyvinyl alcohol (NPVOH) and 40 phr glycerol plasticized polyvinyl alcohol (PPVOH) were measured using a method known as power compensate differential scanning calorimetry. A high purity sapphire (Al2O3) was used as a reference material. NPVOH has a melting temperature of approximately 480 K, while PPVOH has a value of 30 K lower than NPVOH. The amplitude increment of Csp for NPVOH was also higher than PPVOH at melting stage. Overall, Csp of NPVOH is lower than PPVOH because glycerol has reduced the rigidity of PVOH and subsequently induced the motion of molecular structure at an elevated temperature. Based on the specific heat outcomes, neat PVOH and glycerol plasticized PVOH required 1173.544 J/g and 1946.631 J/g, respectively, to heat from 330 to 550 K.
    Matched MeSH terms: Polyvinyl Alcohol
  7. Yusof Y, Moosavi S, Johan MR, Badruddin IA, Wahab YA, Hamizi NA, et al.
    ACS Omega, 2021 Feb 16;6(6):4184-4191.
    PMID: 33644542 DOI: 10.1021/acsomega.0c04864
    This study presents the electromagnetic (EM) characterization of a multiwalled carbon nanotubes (MWCNT)-silver nanoparticles (AgNP)-reinforced poly(vinyl alcohol) (PVA) hybrid nanocomposite fabricated via the solution mixing technique. Primarily, the structure and morphological properties of the PVA/MWCNT-AgNP hybrid nanocomposite are confirmed by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The complex permittivity (ε*) and permeability (μ*), as well as the electromagnetic scattering parameters are measured using a PNA network analyzer equipped with X-band waveguide. The results showed an enhanced permittivity (ε' ≈ 25) value of the hybrid nanocomposite in the frequency range of 8-12 GHz. However, the permeability decreased to almost zero (μ' ≈ 0.4) since the inclusion of AgNP with an average particle size of 40 nm is not susceptible to magnetization and causes higher magnetic losses (tan δμ) than dielectric losses (tan δε). Remarkably, the hybrid nanocomposite reduced transmission of electromagnetic (EM) wave by nearly 60% in comparison to PVA/MWCNT. This is attributed to the enhanced absorption and reflection at the nanotubes, and metal-dielectric interfaces have induced multiple internal reflections owing to the porous structure of the nanocomposite. The prospect of the PVA/MWCNT-AgNP hybrid nanocomposite is favorable as a thin absorbing material for EM shielding applications.
    Matched MeSH terms: Polyvinyl Alcohol
  8. Ebadi M, Bullo S, Buskaran K, Hussein MZ, Fakurazi S, Pastorin G
    Polymers (Basel), 2021 Mar 10;13(6).
    PMID: 33802205 DOI: 10.3390/polym13060855
    Iron oxide nanoparticles are suitable for biomedical applications owing to their ability to anchor to various active agents and drugs, unique magnetic properties, nontoxicity, and biocompatibility. In this work, the physico-chemical and magnetic properties, as well as the cytotoxicity, of Fe3O4 nanoparticles coated with a polymeric carrier and loaded with a 5-fluorouracil (5-FU) anti-cancer drug are discussed. The synthesized Fe3O4 nanoparticles were coated with polyvinyl alcohol and Zn/Al-layered double hydroxide as the drug host. The XRD, DTA/TG, and FTIR analyzes confirmed the presence of the coating layer on the surface of nanoparticles. The results showed a decrease in saturation magnetization of bare Fe3O4 nanoparticles after coating with the PVA/5FU/Zn/Al-LDH layer. In addition, the presence of the coating prevented the agglomeration of nanoparticles. Furthermore, the pseudo-second-order equation governed the kinetics of drug release. Finally, the coated nanoparticles showed stronger activity against liver cancer cells (HepG2) compared to that of the naked 5-FU drug, and displayed no cytotoxicity towards 3T3 fibroblast cell lines. The results of the present study demonstrate the potential of a nano delivery system for cancer treatment.
    Matched MeSH terms: Polyvinyl Alcohol
  9. Mawazi SM, Doolaanea AA, Hadi HA, Chatterjee B
    Int J Pharm, 2021 Jun 01;602:120638.
    PMID: 33901596 DOI: 10.1016/j.ijpharm.2021.120638
    Crystallinity plays a vital role in the pharmaceutical industry. It affects drug manufacturing, development processes, and the stability of pharmaceutical dosage forms. An objective of this study was to measure and analyze the carbamazepine (CBZ) crystallinity before and after formulation. Moreover, it intended to determine the extent to which the crystallinity of CBZ would affect the drug loading, the particle size, and the release of CBZ from the microparticles. The CBZ microparticles were prepared by encapsulating CBZ in ethyl cellulose (EC) polymer using a solvent evaporation method. EC was used here as a release modifier polymer and polyvinyl alcohol (PVA) as an aqueous phase stabilizer. Factorial design was used to prepare the CBZ microparticle formulations, including polymer concentration, solvent (dichloromethane, ethyl acetate), PVA concentrations factor, the homogenization time, and homogenization speed. The crystallinity of CBZ was calculated utilizing differential scanning calorimetry (DSC) thermal analysis. The crystallinity was calculated from the enthalpy of CBZ. Enthalpy was analyzed from the area under the curve peak of CBZ standard and CBZ-loaded microparticles. DSC and ATR-FTIR assessed the possible interaction between CBZ and excipients in the microparticle. The prepared CBZ microparticles showed various changes in the crystallinity rate of CBZ. The changes in the rate of CBZ crystallinity had different effects on the particle size, the drug loading, and the release of CBZ from the polymer. Statistically, all studied factors significantly affected the crystallinity of CBZ after formulation to microparticles.
    Matched MeSH terms: Polyvinyl Alcohol
  10. Aziz SB, Nofal MM, Kadir MFZ, Dannoun EMA, Brza MA, Hadi JM, et al.
    Materials (Basel), 2021 Apr 16;14(8).
    PMID: 33923484 DOI: 10.3390/ma14081994
    This report shows a simple solution cast methodology to prepare plasticized polyvinyl alcohol (PVA)/methylcellulose (MC)-ammonium iodide (NH4I) electrolyte at room temperature. The maximum conducting membrane has a conductivity of 3.21 × 10-3 S/cm. It is shown that the number density, mobility and diffusion coefficient of ions are enhanced by increasing the glycerol. A number of electric and electrochemical properties of the electrolyte-impedance, dielectric properties, transference numbers, potential window, energy density, specific capacitance (Cs) and power density-were determined. From the determined electric and electrochemical properties, it is shown that PVA: MC-NH4I proton conducting polymer electrolyte (PE) is adequate for utilization in energy storage device (ESD). The decrease of charge transfer resistance with increasing plasticizer was observed from Bode plot. The analysis of dielectric properties has indicated that the plasticizer is a novel approach to increase the number of charge carriers. The electron and ion transference numbers were found. From the linear sweep voltammetry (LSV) response, the breakdown voltage of the electrolyte is determined. From Galvanostatic charge-discharge (GCD) measurement, the calculated Cs values are found to drop with increasing the number of cycles. The increment of internal resistance is shown by equivalent series resistance (ESR) plot. The energy and power density were studied over 250 cycles that results to the value of 5.38-3.59 Wh/kg and 757.58-347.22 W/kg, respectively.
    Matched MeSH terms: Polyvinyl Alcohol
  11. Gaaz TS, Sulong AB, Akhtar MN, Kadhum AA, Mohamad AB, Al-Amiery AA
    Molecules, 2015;20(12):22833-47.
    PMID: 26703542 DOI: 10.3390/molecules201219884
    The aim of this review was to analyze/investigate the synthesis, properties, and applications of polyvinyl alcohol-halloysite nanotubes (PVA-HNT), and their nanocomposites. Different polymers with versatile properties are attractive because of their introduction and potential uses in many fields. Synthetic polymers, such as PVA, natural polymers like alginate, starch, chitosan, or any material with these components have prominent status as important and degradable materials with biocompatibility properties. These materials have been developed in the 1980s and are remarkable because of their recyclability and consideration of the natural continuation of their physical and chemical properties. The fabrication of PVA-HNT nanocomposites can be a potential way to address some of PVA's limitations. Such nanocomposites have excellent mechanical properties and thermal stability. PVA-HNT nanocomposites have been reported earlier, but without proper HNT individualization and PVA modifications. The properties of PVA-HNT for medicinal and biomedical use are attracting an increasing amount of attention for medical applications, such as wound dressings, drug delivery, targeted-tissue transportation systems, and soft biomaterial implants. The demand for alternative polymeric medical devices has also increased substantially around the world. This paper reviews individualized HNT addition along with crosslinking of PVA for various biomedical applications that have been previously reported in literature, thereby showing the attainability, modification of characteristics, and goals underlying the blending process with PVA.
    Matched MeSH terms: Polyvinyl Alcohol
  12. Husain S, Ramos JA, Karaf JHA, Zahedi FD, Ahmad N, Abdullah B
    Eur Arch Otorhinolaryngol, 2023 Feb;280(2):737-741.
    PMID: 35900386 DOI: 10.1007/s00405-022-07563-9
    PURPOSE: To evaluate the efficacy of topical tranexamic acid (TXA) in reducing intraoperative and immediate postoperative bleeding during functional endoscopic sinus surgery (FESS) among patients with chronic rhinosinusitis with nasal polyposis (CRSwNP).

    METHODS: This is a double-blind randomized clinical trial, involving 26 patients with CRSwNP, who underwent FESS for failed medical therapy. The intervention nostril was packed with ribbon gauze soaked in 500 mg/5 ml TXA. The control nostril was packed with ribbon gauze soaked in Moffett's solution, containing 2 ml 10% cocaine, 1 ml adrenaline 1:1000, and 4 ml 0.9% sodium bicarbonate. Both nostrils were packed for 15 min before FESS. Intraoperative bleeding was recorded in the initial 30 min after commencing the surgery. The recordings were reviewed by two surgeons using Boezaart's scoring system. The scores were taken at 15 and 30 min of surgery. The mean score was then calculated. At the end of the surgery, the intervention nostril was packed with Merocel® soaked in 500 mg/5 ml TXA and the control nostril was packed with Merocel® soaked in normal saline. The amount of bleeding within 24 h post-surgery was evaluated using a bolster gauze.

    RESULTS: There was no significant difference in intraoperative bleeding between the intervention (1.54 ± 0.71) and control nostrils (1.69 ± 0.55) with p = 0.172. The amount of bleeding in the postoperative period was significantly reduced in the intervention nostril (1.33 ± 0.55) compared to the control nostril saline (1.81 ± 0.48) with p = 0.001.

    CONCLUSIONS: We found that the nasal packing soaked in TXA reduced intraoperative and immediate postoperative bleeding. It is a safe, efficacious and cost-effective alternative to Moffett's solution during FESS and also an alternative to normal saline post-surgery among patients with CRSwNP.

    TRIAL REGISTRATION NUMBER: FF-2015-232, 2015.

    Matched MeSH terms: Polyvinyl Alcohol
  13. Qi J, Zhang H, Wang Y, Mani MP, Jaganathan SK
    Int J Nanomedicine, 2018;13:2777-2788.
    PMID: 29785105 DOI: 10.2147/IJN.S151242
    Introduction: Currently, the design of extracellular matrix (ECM) with nanoscale properties in bone tissue engineering is challenging. For bone tissue engineering, the ECM must have certain properties such as being nontoxic, highly porous, and should not cause foreign body reactions.

    Materials and methods: In this study, the hybrid scaffold based on polyvinyl alcohol (PVA) blended with metallocene polyethylene (mPE) and plectranthus amboinicus (PA) was fabricated for bone tissue engineering via electrospinning. The fabricated hybrid nanocomposites were characterized by scanning electron microscopy (SEM), Fourier transform and infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement, and atomic force microscopy (AFM). Furthermore, activated partial thromboplastin time (APTT), prothrombin time (PT), and hemolytic assays were used to investigate the blood compatibility of the prepared hybrid nanocomposites.

    Results: The prepared hybrid nanocomposites showed reduced fiber diameter (238±45 nm) and also increased porosity (87%) with decreased pore diameter (340±86 nm) compared with pure PVA. The interactions between PVA, mPE, and PA were identified by the formation of the additional peaks as revealed in FTIR. Furthermore, the prepared hybrid nanocomposites showed a decreased contact angle of 51°±1.32° indicating a hydrophilic nature and exhibited lower thermal stability compared to pristine PVA. Moreover, the mechanical results revealed that the electrospun scaffold showed an improved tensile strength of 3.55±0.29 MPa compared with the pristine PVA (1.8±0.52 MPa). The prepared hybrid nanocomposites showed delayed blood clotting as noted in APTT and PT assays indicating better blood compatibility. Moreover, the hemolysis assay revealed that the hybrid nanocomposites exhibited a low hemolytic index of 0.6% compared with pure PVA, which was 1.6% suggesting the safety of the developed nanocomposite to red blood cells (RBCs).

    Conclusion: The prepared nanocomposites exhibited better physico-chemical properties, sufficient porosity, mechanical strength, and blood compatibility, which favors it as a valuable candidate in bone tissue engineering for repairing the bone defects.

    Matched MeSH terms: Polyvinyl Alcohol/chemistry
  14. Ndlovu ST, Ullah N, Khan S, Ramharack P, Soliman M, de Matas M, et al.
    Drug Deliv Transl Res, 2019 Feb;9(1):284-297.
    PMID: 30387048 DOI: 10.1007/s13346-018-00596-w
    The aim of this study was to employ experimental and molecular modelling approaches to use molecular level interactions to rationalise the selection of suitable polymers for use in the production of stable domperidone (DOMP) nanocrystals with enhanced bioavailability. A low-energy antisolvent precipitation method was used for the preparation and screening of polymers for stable nanocrystals of DOMP. Ethyl cellulose was found to be very efficient in producing stable DOMP nanocrystals with particle size of 130 ± 3 nm. Moreover, the combination of hydroxypropyl methylcellulose and polyvinyl alcohol was also shown to be better in producing DOMP nanocrystals with smaller particle size (200 ± 3.5 nm). DOMP nanosuspension stored at 2-8 °C and at room temperature (25 °C) exhibited better stability compared to the samples stored at 40 °C. Crystallinity of the unprocessed and processed DOMP was monitored by differential scanning calorimetry and powder X-ray diffraction. DOMP nanocrystals gave enhanced dissolution rate compared to the unprocessed drug substance. DOMP nanocrystals at a dose of 10 mg/kg in rats showed enhanced bioavailability compared to the raw drug substance and marketed formulation. A significant increase in plasma concentration of 2.6 μg/mL with a significant decrease in time (1 h) to reach maximum plasma concentration was observed for DOMP nanocrystals compared to the raw DOMP. Molecular modelling studies provided underpinning knowledge at the molecular level of the DOMP-polymer nanocrystal interactions and substantiated the experimental studies. This included an understanding of the impact of polymers on the size of nanocrystals and their associated stability characteristics.
    Matched MeSH terms: Polyvinyl Alcohol/chemistry*
  15. Abdullah Issa M, Z Abidin Z
    Molecules, 2020 Aug 03;25(15).
    PMID: 32756377 DOI: 10.3390/molecules25153541
    As a remedy for environmental pollution, a versatile synthetic approach has been developed to prepare polyvinyl alcohol (PVA)/nitrogen-doped carbon dots (CDs) composite film (PVA-CDs) for removal of toxic cadmium ions. The CDs were first synthesized using carboxymethylcellulose (CMC) of oil palms empty fruit bunch wastes with the addition of polyethyleneimine (PEI) and then the CDs were embedded with PVA. The PVA-CDs film possess synergistic functionalities through increasing the content of hydrogen bonds for chemisorption compared to the pure CDs. Optical analysis of PVA-CDs film was performed by ultraviolet-visible and fluorescence spectroscopy. Compared to the pure CDs, the solid-state PVA-CDs displayed a bright blue color with a quantum yield (QY) of 47%; they possess excitation-independent emission and a higher Cd2+ removal efficiency of 91.1%. The equilibrium state was achieved within 10 min. It was found that adsorption data fit well with the pseudo-second-order kinetic and Langmuir isotherm models. The maximum adsorption uptake was 113.6 mg g-1 at an optimal pH of 7. Desorption experiments showhe that adsorbent can be reused fruitfully for five adsorption-desorption cycles using 0.1 HCl elution. The film was successfully applied to real water samples with a removal efficiency of 95.34% and 90.9% for tap and drinking water, respectively. The fabricated membrane is biodegradable and its preparation follows an ecofriendly green route.
    Matched MeSH terms: Polyvinyl Alcohol/chemistry*
  16. Ahmed AS, Mandal UK, Taher M, Susanti D, Jaffri JM
    Pharm Dev Technol, 2018 Oct;23(8):751-760.
    PMID: 28378604 DOI: 10.1080/10837450.2017.1295067
    The development of hydrogel films as wound healing dressings is of a great interest owing to their biological tissue-like nature. Polyvinyl alcohol/polyethylene glycol (PVA/PEG) hydrogels loaded with asiaticoside, a standardized rich fraction of Centella asiatica, were successfully developed using the freeze-thaw method. Response surface methodology with Box-Behnken experimental design was employed to optimize the hydrogels. The hydrogels were characterized and optimized by gel fraction, swelling behavior, water vapor transmission rate and mechanical strength. The formulation with 8% PVA, 5% PEG 400 and five consecutive freeze-thaw cycles was selected as the optimized formulation and was further characterized by its drug release, rheological study, morphology, cytotoxicity and microbial studies. The optimized formulation showed more than 90% drug release at 12 hours. The rheological properties exhibited that the formulation has viscoelastic behavior and remains stable upon storage. Cell culture studies confirmed the biocompatible nature of the optimized hydrogel formulation. In the microbial limit tests, the optimized hydrogel showed no microbial growth. The developed optimized PVA/PEG hydrogel using freeze-thaw method was swellable, elastic, safe, and it can be considered as a promising new wound dressing formulation.
    Matched MeSH terms: Polyvinyl Alcohol/chemistry*
  17. Khan MUA, Iqbal I, Ansari MNM, Razak SIA, Raza MA, Sajjad A, et al.
    Molecules, 2021 Sep 30;26(19).
    PMID: 34641480 DOI: 10.3390/molecules26195937
    The present research is based on the fabrication preparation of CS/PVA/GG blended hydrogel with nontoxic tetra orthosilicate (TEOS) for sustained paracetamol release. Different TEOS percentages were used because of their nontoxic behavior to study newly designed hydrogels' crosslinking and physicochemical properties. These hydrogels were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and wetting to determine the functional, surface morphology, hydrophilic, or hydrophobic properties. The swelling analysis in different media, degradation in PBS, and drug release kinetics were conducted to observe their response against corresponding media. The FTIR analysis confirmed the components added and crosslinking between them, and surface morphology confirmed different surface and wetting behavior due to different crosslinking. In various solvents, including water, buffer, and electrolyte solutions, the swelling behaviour of hydrogel was investigated and observed that TEOS amount caused less hydrogel swelling. In acidic pH, hydrogels swell the most, while they swell the least at pH 7 or higher. These hydrogels are pH-sensitive and appropriate for controlled drug release. These hydrogels demonstrated that, as the ionic concentration was increased, swelling decreased due to decreased osmotic pressure in various electrolyte solutions. The antimicrobial analysis revealed that these hydrogels are highly antibacterial against Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains. The drug release mechanism was 98% in phosphate buffer saline (PBS) media at pH 7.4 in 140 min. To analyze drug release behaviour, the drug release kinetics was assessed against different mathematical models (such as zero and first order, Higuchi, Baker-Lonsdale, Hixson, and Peppas). It was found that hydrogel (CPG2) follows the Peppas model with the highest value of regression (R2 = 0.98509). Hence, from the results, these hydrogels could be a potential biomaterial for wound dressing in biomedical applications.
    Matched MeSH terms: Polyvinyl Alcohol/chemistry*
  18. Malek NNA, Jawad AH, Ismail K, Razuan R, ALOthman ZA
    Int J Biol Macromol, 2021 Oct 31;189:464-476.
    PMID: 34450144 DOI: 10.1016/j.ijbiomac.2021.08.160
    A magnetic biocomposite blend of chitosan-polyvinyl alcohol/fly ash (m-Cs-PVA/FA) was developed by adding fly ash (FA) microparticles into the polymeric matrix of magnetic chitosan-polyvinyl alcohol (m-Cs-PVA). The effectiveness of m-Cs-PVA/FA as an adsorbent to remove textile dye (reactive orange 16, RO16) from aquatic environment was evaluated. The optimum adsorption key parameters and their significant interactions were determined by Box-Behnken Design (BBD). The analysis of variance (ANOVA) indicates the significant interactions can be observed between m-Cs-PVA/FA dose with solution pH, and m-Cs-PVA/FA dose with working temperature. Considering these significant interactions, the highest removal of RO16 (%) was found 90.3% at m-Cs-PVA/FA dose (0.06 g), solution pH (4), working temperature (30 °C), and contact time (17.5 min). The results of adsorption kinetics revealed that the RO16 adsorption was better described by the pseudo-second-order model. The results of adsorption isotherm indicated a multilayer adsorption process as well described by Freundlich model with maximum adsorption capacity of 123.8 mg/g at 30 °C. An external magnetic field can be easily applied to recover the adsorbent (m-Cs-PVA/FA). The results supported that the synthesized m-Cs-PVA/FA presents itself as an effective and promising adsorbent for textile dye with preferable adsorption capacity and separation ability during and after the adsorption process.
    Matched MeSH terms: Polyvinyl Alcohol/chemistry*
  19. Idris A, Misran E, Hassan N, Abd Jalil A, Seng CE
    J Hazard Mater, 2012 Aug 15;227-228:309-16.
    PMID: 22682796 DOI: 10.1016/j.jhazmat.2012.05.065
    In this study magnetic separable photocatalyst beads containing maghemite nanoparticles (γ-Fe(2)O(3)) in polyvinyl alcohol (PVA) polymer were prepared and used in the reduction of Cr(VI) to Cr(III) in an aqueous solution under sunlight. The unique superparamagnetic property of the photocatalyst contributed by the γ-Fe(2)O(3) and robust property of PVA polymer allow the magnetic beads to be recovered easily and reused for at least 7 times without washing. The concentration of γ-Fe(2)O(3) was varied from 8% (v/v) to 27% (v/v) and the results revealed that the beads with 8% (v/v) γ-Fe(2)O(3) exhibited the best performance where Cr(VI) was reduced to Cr(III) in only 30 min under sunlight. The use of the PVA has improved the bead properties and life cycle of beads which is in line with sustainable practices.
    Matched MeSH terms: Polyvinyl Alcohol/chemistry*
  20. Almurisi SH, Mohammed A, Qassem F, Jehad H, Jassim A, Al-Japairai K, et al.
    Curr Drug Discov Technol, 2024;21(3):46-55.
    PMID: 37807409 DOI: 10.2174/0115701638262447230920061222
    AIM: This study aimed to formulate and characterize aceclofenac buccal film formulations made of different polymers and evaluate the effects of polymer type on buccal film properties.

    MATERIALS AND METHODS: Five polymer types, namely hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose (SCMC), polyvinyl alcohol (PVA), Eudragit S100, and Eudragit SR100, were used to prepare aceclofenac buccal film formulation either separately or combined by solvent-casting method. These formulations were evaluated in terms of physical appearance, folding test, film weight and thickness, drug content, percentage of elongation, moisture uptake, water vapor permeability, and in vitro drug release.

    RESULTS: The addition of Eudragit polymer in most of the produced buccal films was unacceptable with low folding endurance. However, the dissolution profile of buccal films made from PVA and Eudragit SR100 provided a controlled drug release profile.

    CONCLUSION: Buccal films can be formulated using different polymers either individually or in combination to obtain the drug release profile required to achieve a desired treatment goal. Furthermore, the property of the buccal films depends on the type and concentration of the polymer used.

    Matched MeSH terms: Polyvinyl Alcohol/chemistry
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