Biodegradability, antimicrobial activity and properties of PVA/PVP hydrogels prepared by γ-irradiation

Journal of Polymer Research (Impact Factor: 1.9). 01/2008; 16(1):1-10. DOI: 10.1007/s10965-008-9196-0

ABSTRACT Polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) hydrogel has been prepared by using γ-irradiation technique. In the present
study the conclusion on miscibility of PVA/PVP blends, confirmed qualitatively and quantitatively by using Fourier transform
infrared spectroscopy and differential scanning calorimetry, respectively. PVA and PVP are found to form a thermodynamically
miscible pair. The physical properties such as gel fraction and water absorption performance of the prepared hydrogels were
measured, it was found that the gel fraction increases with increasing irradiation dose while the swelling of PVA/PVP blended
hydrogels nearly tends to increase with increasing PVP content and reduced with enhanced irradiation doses. The hydrogel pore
structure of various PVA/PVP compositions were tested with SEM. Ability of PVA/PVP hydrogels to absorb and release antimicrobial
compounds was tested using amoxicillin as an antibacterial and ketoconazole as an antifungal. Antimicrobial activity of PVA/PVP
hydrogels was examined using four bacteria, and four fungi. No antibacterial or antifungal activities of non-loaded PVA/PVP
of various compositions were detected while the loading ones found to have antimicrobial activity. Results showed resistance
of Pseudomonas aeruginosa and Candida albicans to PVA/PVP, while Bacillus subtilis was very sensitive. Biodegradation of PVA/PVP hydrogels was investigated by burial method in two types of local soils (clay
and sandy soils). The highest degradation rate was found to be achieved using clay soil. Also, effect of irradiation dose
on its biodegradability was tested. The results showed that the radiation prepared PVA/PVP hydrogels can be use as biomaterials.

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    ABSTRACT: Poly(N-vinyl-2-pyrrolidone)/(acrylic acid-co-styrene) [PVP/(AAc-co-Sty)] hydrogels were prepared by γ-irradiation to design as adsorptive systems. The adsorption of agricultural pesticides Fluometuron (FH), Thiophanate Methyl (TF) and Trifluralin (TI) on radiation-induced graft copolymeric adsorbents has been studied. The prepared hydrogels were characterized by FT-IR spectroscopy, scanning electron microscopy (SEM), and the thermal properties were studied by using thermal gravimetric analysis (TGA) and Differential scanning calorimetry (DSC). The ionic character of the prepared hydrogel was improved by treatment with alkaline (NaOH), sulfonation (Sf) and alkaline/sulfonation (NaOH/Sf). The swelling as a function of PVP concentration, AAc/Sty composition, irradiation dose, temperature and pH were studies. The adsorption of pesticides on the hydrogel matrix under different conditions was studied to determine which factors have the most affect and control the adsorption capacity of hydrogel. AAc/Sty composition, type of pesticide, temperature, concentration and pH of pesticide feed solution are greatly affect the pesticide uptake. It was found that the prepared hydrogels have a great efficiency to recover the pesticides from their solutions, the maximum pesticide uptake was found to be in the sequence: TI > TF > FH. The results concluded that the alkaline/sulfonation- treated PVP/(AAc-co-Sty) hydrogels possess high efficiency for removal of pesticides.
    Journal of Macromolecular Science Part A 10/2012; 49(10):814-827. DOI:10.1080/10601325.2012.714325 · 0.74 Impact Factor
  • Ecological Chemistry and Engineering. S = Chemia i Inżynieria Ekologiczna. S 01/2013; 20(1). DOI:10.2478/eces-2013-0015 · 0.56 Impact Factor
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    ABSTRACT: Surface active compounds may act as effective additives modifying water lubricity. Their action mechanism consists in the formation of a lubricating film enriched with an active compound. The reasons for the choice of polyvinylpyrrolidones as additives were their physiological inertness and a lack of harmful environmental effects. The tests were carried out on the solutions of two polyvinylpyrrolidones with degrees of polymerization of 450 (PVP 450) and 14400 (PVP 14400). A significant effect of the polymer chain length on physicochemical (viscosity, surface tension, wettability of steel) and tribological properties (resistance to motion, wear, scuffing) has been found. PVP 14400 showed a considerably greater ability to thicken solutions. Over 10 times higher coefficients of viscosity relative to an analogous PVP 450 solution were observed already at a concentration of 5%. A slightly higher ability of PVP 14400 to reduce surface tension was observed. In the case of wettability of steel, a more effective decrease in the wetting angle was observed for PVP 450. However, the differences obtained were not large and usually did not exceed 20%. The measurements of resistance to motion and wear at three constant loads (2000, 3000, 4000 N) as well as tests on antiseizure abilities under a constant velocity increment of load (409 N/s) were carried out using a four-ball tester (T-02 tester). All friction pairs were made of bearing steel. Introducing additives to water significantly affects a decrease in resistance to motion and wear as well as an increase in the ability of a tribological system to prevent seizure. The system did not undergo seizure even at a load of 4 kN. A 2-fold decrease in the coefficient of friction (μ) and an over 30% decrease in the value of wear scar diameters (d) relative to water were observed for PVP 450 and PVP 14400 solutions at 2.0 kN. The use of water as a lubricant led to seizure of the tribological system already at above 2 kN. Addition of the polymers to water also results in a significant improvement in its antiseizure properties. The values of scuffing load (Pt) and limiting pressure of seizure (poz) for individual solutions were even 5 and 15 times higher, respectively, than the values for water. Seizure load (Poz) was also relatively high, and its level was almost two times higher than that for water. The results obtained indicate that polyvinylpyrrolidone used as an additive considerably improves the tribological characteristics of water as a lubricant base.
    Industrial & Engineering Chemistry Research 10/2012; 51(45):14700–14707. DOI:10.1021/ie301431v · 2.24 Impact Factor