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1

Sustained Release of Drug Facilitated Through Chemically Crosslinked Polyvinyl Alcohol-Gelatin (PVA-GE) Hydrogels. A sustainable biomedical approach

Ali Shaukat, Ranjha Nazar Muhammad, Ahmad Bashir, Khan Ayaz Ali, Hassan Fakhr Ul, Aziz Tariq, Alharb Metab, Alshammari Abdulrahman, Alasmari Abdullah F., Alharbi Mousa Esa

Polish Journal of Chemical Technology

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2023

|

Vol. 25, nr 2

56--65

EN

The present study aimed to prepare hydrogel based on polyvinyl alcohol (PVA) and gelatin (Ge) and characterization of PVA/Ge hydrogel for their potential use as a sustained drug delivery system. Polyvinyl Alcohol (PVA) and-Gelatin (Ge) were cross-linked using glutaraldehyde (GA) as a crosslinking agent and hydrochloric acid (HCl) as a catalyst. Different feed polymer ratio and crosslinking agent concentration were used to prepare a series of PVA/Ge hydrogels. The obtained PVA/Ge hydrogels were investigated for dynamic and equilibrium swelling studies. The effect of polymers ratio, degree of crosslinking and pH of the medium on swelling of PVA/Ge hydrogels was investigated. Furthermore, the values of diffusion coeficient (D), volume fraction, polymer-solvent interaction parameter, molecular weight between crosslink and crosslink density were calculated. For swelling studies, 0.05M USP phosphate buffer solutions of different pH (1.2, 5.5, 6.5 and 7.5) were used. For the drug release study, ciprofloxacin HCl was loaded into selected samples as a model drug. The release of drug from these samples was performed for 12 hours in USP phosphate buffers of pH 1.2, 5.5 and 7.5. The release data from these samples were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models to investigate the release mechanism. It was found that by varying the composition of PVA/Ge hydrogel and GA concentration, a significant difference was observed in drug release kinetics. FTIR spectroscopy and X-ray diffraction were used for the characterization of hydrogels. PVA/Ge hydrogel showed sustained release of the model drug at various pH values suggesting its potential use as a sustained drug delivery system.

2

Production of Superabsorbent Biopolymer from Modified Cellulose-Based Polivinyl Alcohol with Variation of the Number of Initiator and Crosslink Agent

Susmanto Prahady, Putri Aulia Rahmani, Nugraha Mohamad Zaky

Journal of Ecological Engineering

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2023

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Vol. 24, nr 6

98--108

EN

The problems that are often encountered in the results of the development of material modification of super absorbent polymers include water absorption ability and ability swelling which is low, limited solubility in water and organic compounds, in addition to the condition of the material that is hard and brittle and not environmentally friendly, also being difficult to decompose. These conditions can be minimized and improved through modification of monomer compounds, crosslinker, and initiator in the polymerization process. The polymerization process is carried out by the method of chemical crosslinker with crosslink agent i.e. formaldehyde in the main chain (backbone), namely polyvinyl alcohol, and daughter chains, i.e. bagasse cellulose, with the help of an initiator in the form of potassium persulfate. The results of the study showed that formation of a new functional group (C-OH stretch) at 1143.30 cm-1; (-OH) at 3461.03 cm-1; (C-O-C) at 1200.55 cm-1; (C=O) at 1529.86 cm-1. The highest absorption capacity reached 746.49% in the sample with 0.8 gram of initiator and crosslink 0.8 mL. Mark Swelling the highest was obtained under acidic conditions, namely pH 6 with a value of 358.30. The surface morphology of the superabsorbent, which is a dense, strong and elastic surface, is formed with pores ±11.75 nm. The surface change proves that the grafting process and interfacial interactions of two materials are going well.

3

Development and Characterization of Polyvinyl Alcohol/Bacterial Cellulose Composite for Environmentally Friendly Film

Singhaboot Pakjirat, Kraisuwan Wilaiporn, Chatkumpjunjalearn Tanwalai, Kroeksakul Patarapong, Chongkolnee Boonsong

Journal of Ecological Engineering

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2023

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Vol. 24, nr 6

226--238

EN

This research aimed to develop and characterize polyvinyl alcohol (PVA)/bacterial cellulose (BC) composite for environmentally friendly films. BC was produced from a high-performance strain of Komagataeibacter intermedius BE073 isolated from a bio-extract sample. The film was prepared by varying the ratio between PVA and BC content, and treatments consisted of 100:0, 90:10, 80:20, 70:30, and 60:40. The characterization of PVA/BC film in terms of mechanical properties, film structure, water and oxygen resistances, thermal stability, and biodegradation were investigated. Results revealed that PVA/BC film had properties superior to that of pure PVA film, and it has a high biodegradation rate. The mechanical properties changed little with the addition of BC, but the tensile strength and Young’s modulus increased with the addition of BC. Water absorption and moisture content were also reduced. However, adding BC improved oxygen transmission rates and thermal stability properties. Most importantly, the addition of BC helped the film to degrade. The higher the amount added, the higher the natural decomposition rate.

4

Characterization of Nanocomposite Mixture Polyvinyl Alcohol and Rice Husk Ash

Sirait Makmur, Sinulingga Karya, Siregar Nurdin

Journal of Ecological Engineering

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2023

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Vol. 24, nr 11

268–-273

EN

Rice husk ash (RHA) nanoparticles were prepared to be applied as a filler in the formation of Polyvinyl Alcohol (PVA) nanocomposites. The manufacture of rice husk ash nanoparticles involved the Ball Mill method and the coprecipitation method, while the manufacture of Polyvinyl Alcohol nanocomposite membranes and rice husk ash was carried out by the sol-gel method. The results of XRD analysis using Match software indicated that the crystal structure of rice husk ash is monoclinic with a particle size of 16.55 nm. The mechanical test results obtained the largest elastic modulus of 29.28 MPa in 3% rice husk ash mixture, the largest tensile test of 8.83 MPa in 1% rice husk ash mixture, and the largest elongation at break of 82.08% in 4% rice husk ash mixture. The addition of rice husk ash as a filler can improve the mechanical properties of PVA/rice husk ash nanocomposites.

5

Biopolishing of Domestic Wastewater Using Polyvinyl Alcohol – Supported Biofilm of Bacterial Strain Bacillus velezensis Isolate JB7

Othman Muhammad Faidsyafiq, Hasan Hassimi Abu, Muhamad Mohd Hafizuddin, Babaqi Badiea S.

Journal of Ecological Engineering

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2023

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Vol. 24, nr 8

33--42

EN

Water pollution occurs due to the discharge of domestic waste mixed with residential, industrial, commercial, and agricultural wastewater. Conventional water treatment methods using aerobic/anaerobic methods can cause problems with the production of high green gases and result in the greenhouse effect. Microbial-based domestic sewage treatment technology using polyvinyl alcohol biofilm supporting media was introduced as an alternative measure to overcome this problem. The objective of the study was to determine the performance of polyvinyl alcohol beads in polishing domestic wastewater. In this study, the bacterium Bacillus velezensis isolate JB7 was used together with PVA as a raw material to treat domestic sewage wastewater more efficiently and stably. The results of the study show the effectiveness of domestic wastewater treatment in several factors such as pH value, chemical oxygen demand, phosphorus, nitrate, nitrite, ammonia, and total suspended solids. As conclusion, domestic wastewater treatment methods using polyvinyl alcohol beads are seen to be effective, reducing the use of sewage waste plant construction sites and able to avoid the use of non-recyclable materials such as plastics and synthetics.

6

Comparative assessment of intranasal dressings made of various types of biomaterials, applied after functional endoscopic sinus surgery

Maou Azad, Likus Wirginia, Długosz-Karbowska Anna, Pilch Jan, Markowski Jarosław

Engineering of Biomaterials

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2023

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vol. 26, no. 171

18--22

EN

The aim of the study was to make a comparative evaluation of four different types of intranasal dressings made from various types of biomaterials (three original dressings manufactured by various commercial suppliers, and the fourth one, in the form of nasal tamponage by means of a seton in a latex glove finger cot), concerning their efficacy as regards haemostatic action, assessment of postoperative pain, as well as proneness to the occurrence of postoperative adhesions. All patients who were qualified for the study were operated on in the ENT Department, Medical University of Silesia in Katowice, Poland, due to chronic bilateral inflammation of the para-nasal sinuses, confirmed by computer tomography of the sinuses. A total of 180 patients were qualified for the study. After surgery, 4 different kinds of intranasal haemostatic dressings were applied. The results were analyzed in three categories: effectiveness in the field of haemostatic activity, postoperative pain assessment (Visual Analog Scale, VAS), and assessment of the tendency to develop postoperative adhesions. Statistical analysis revealed no statistically significant differences between the 4 types of dressings in both haemostatic efficacy (p = 0.97) and the occurrence of postoperative adhesions (p = 0.84). Analysis of the intensity of pain according to the VAS scale indicated that it did not differ between the analyzed groups, both during the application of dressing (mild pain) and on the second day after the operation (medium intensity pain) – p = 0.30 and p = 0.39, respectively. No advantage has been demonstrated for any of the 4 analysed types of intranasal haemostatic dressings over any other. Their properties turn out to be comparable.

7

Hydro-cracked light gas oil biodesulphurisation by immobilised Pseudomonas aeruginosa cells on polyvinyl alcohol

Khosh Ravesh Hussein, Sadeghi Soroor, Sharifi Sara

Ecological Chemistry and Engineering. S

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2023

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Vol. 30, nr 4

567--580

EN

Refining petroleum fractions containing heterocyclic sulphur compounds to produce sulphur-free fuels, requires efficient desulphurisation methods. A new biocatalyst has been synthesised by immobilising Pseudomonas aeruginosa cells on polyvinyl alcohol by adsorption for hydro-cracked light gas oil bio-desulphurisation. The surface functional groups and biocatalyst morphology have been investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. The bio-desulphurisation of dibenzothiophene as a heterocyclic sulphur model compound of gas oil was achieved with an aqueous-oil ratio (v/v) of 50 %, where the removed mass was 0.3826 mg per gram of biocatalyst at equilibrium condition, bio-desulphurisation rate of 0.375 h–1 and removal percentage was 95.65 %. The biodegradation of dibenzothiophene and its derivatives in hydro-cracked light gas oil has been determined after a batch process using 0.5 g of the biocatalyst after 5 h of contact time at 37 °C. According to gas chromatography - mass spectrometry, ethyl and trimethyl derivatives of dibenzothiophene have been degraded by higher efficiencies in comparison with other derivatives. Also, thiophenes and mercaptans of the gasoil sample have been degraded simultaneously to some extent. Equilibrium data have been observed to obey the pseudo-first-order kinetic model. The cell immobilisation facilitates the interaction of surface functional groups with sulphur compounds. The synergistic effect of cell immobilisation on the bio-activity of bacterial cells was due to the maintenance of the heterotrophic, bacillus morphology of the cells after immobilisation. This approach provides a simple, economical method with mild operating conditions to produce low-sulphur light gas oil through the biodegradation of heterocyclic sulphur compounds.

8

Experimental investigation on the interactions of PVA and quicklime in the soil for earthen sites

Zhang Qiyong, Yu Xiaoniu, Chen Wenwu

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e153, 2023

EN

Earthen sites (i.e., ancient earthen buildings) with important historical, cultural, artistic, social, and scientific value have been seriously damaged. Soil treatment with chemical additives can decrease the degradation rate of earthen sites. In the past, polyvinyl alcohol (PVA) and quicklime as chemical additives were studied separately for the protection of earthen sites. In arid and semi-arid northwest China, the early strength of the lime-treated soil may be insufficient due to an inappropriate reaction environment, and the PVA as the additive can quickly increase the soil strength. However, calcium carbonate has been proven to not be decomposed for hundreds of years, while there is still a lack of experimental evidence to show that the PVA cannot be decomposed in decades. The PVA and lime as the additives show the potential to make up for the defects each other. Therefore, the physical and mechanical properties of the PVA and lime composite soil are analysed, and the microscopic properties of the composite soil are discussed in this study. The results show that the addition of the PVA decreases water vapour permeability and pore size, which causes a delay in the carbonization reaction of lime, but it acts as a cementing agent to improve soil strength before the lime appropriately reacts. The addition of quicklime can decrease the hydrophobicity of the PVA-treated soil. The mixing of these two materials is conducive to the colour control of the sample. For the composite soil applied to earthen sites in northwest China, the optimal ratio is 10% lime and 1.0% PVA.

9

Innovative NPK Fertilizers based on Polyacrylamide and Polyvinyl Alcohol with Controlled Release of Nutrients

Białkowska Anita, Borycka Bożena, Bakar Mohamed, Rzany Agnieszka

Polish Journal of Chemical Technology

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2022

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Vol. 24, nr 3

14--18

EN

The aim of the present work was the preparation and properties evaluation of two innovative fertilizers based on multicomponent polymers characterized by a controlled release of nutrients. One method was based on a multi-component liquid containing different amounts of microelements NPK 12-5-6 fertilizers with polyacrylamide hydrogel beads. The second method concerned the cross-linking of biodegradable polyvinyl alcohol with multi-component NPK fertilizers. Polyacrylamide-based compositions with the highest amount of NPK salts as well as polyvinyl alcohol-based fertilizers in dense gel form, based on 60 phr crosslinking concentrate have shown optimal properties. Regardless of the type of fertilizers used, their components were released slowly. The obtained fertilizers were classifi ed according to the kinetics of nutrient release. Fertilizers made from polyacrylamide based fertilizers have been classifi ed into a group of controlled release fertilizers (CRF), while those made from biodegradable environmentally friendly polyvinyl alcohol have been defi ned as slow released fertilizers (SRF).

10

Composites based on polyvinyl alcohol, chitosan, and curcumin for wound healing applications

Tahir Muhammad, Vicini Silvia, Sionkowska Alina

Engineering of Biomaterials

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2022

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vol. 25, no. 167

10--16

EN

Natural polymers, like chitosan, collagen, and alginate, offer promising solutions for wound healing. Derived from natural sources, they exhibit biocompatibility and bioactivity, promoting tissue regeneration. These polymers can form scaffolds or dressings that accelerate wound closure while reducing infection risks. Their inherent properties make them promising options in the quest for effective wound care materials. In this work, composites based on polyvinyl alcohol (PVA), chitosan (Chi), and curcumin (Cur) were prepared. PVA, a synthetic water-soluble polymer, finds extensive use in biomedical and wound-healing applications. It is approved by the U.S. FDA for cosmetic, medical, and wound healing products. Chi, a polysaccharide, is widely used in biomedicine and possesses antibacterial properties. Both PVA and chitosan are biocompatible and exhibit good filming characteristics. Curcumin (Cur) with antibacterial and antioxidant properties is being explored for regenerative medicine. PVA, chitosan, and curcumin were blended. The structure was studied by FTIR, microscopic observations were done with optical and scanning electron microscopes, and the mechanical properties were assessed. FTIR revealed component interactions, while microscopy showed a flat film surface. The polymeric blend (PVA/Chi/Cur) had a Young’s modulus of 1.49 GPa, tensile strength of 47.69 MPa, stress value of 8.39 N, and 35.34% elongation at break. These properties make the blend suitable for consideration in wound healing applications.

11

Hybrid blend membrane using PVA–g–PMA for direct methanol fuel cell applications

Gajbhiye Pratima, Tiwari A.K., Mann Karan, Kahlon J.S., Upadhyay H.

Chemical and Process Engineering

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2022

|

Vol. 43, nr 2

251--254

EN

In the present study, a novel PVA–g–PMA hybrid membrane was developed for application in direct methanol fuel cell (DMFC). Maleic anhydride (MA) was grafted on polyvinyl alcohol (PVA) both ionically and chemically using potassium persulfate (KPS), for the first time. The PVA–g–PMA thus synthesized was then blended with 3–Amino–4–[3–(triethylammonium sulfonato)phenyl amino]phenylene hydrochloride. The prepared membranes were characterized by FT–IR, TGA. 0.0104 S/cm of proton conductivity was found for the membrane. The ion exchange capacity was found to be 2.175 meq/g and the water uptake capacity as 14.9%. The single-chamber fuel cell power density was higher (34.72 mW/cm2) and current density (62.11 mA/cm2) when compared to Nafion 117 membrane.

12

Improved Reduction of COD, BOD, TSS and Oil & Grease from Sugarcane Industry Effluent by Ferric Chloride and Polyaluminum Chloride Coupled with Polyvinyl Alcohol

Panhwar Aijaz, Bhutto Shahid

Ecological Engineering & Environmental Technology

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2021

|

Vol. 22, iss. 2

8--14

EN

Rapid industrialization and urbanization severely affect our environment and water resources. Disposal of untreated wastewater to environment is a great threat to water bodies and environment. Sugarcane industry is an important industrial sector; globally it is also largest source of pollution of surface water and groundwater resources. It comprises a huge amount of chemicals and inorganic pollutants. Many treatment methods have been employed for the treatment of the sugarcane industry wastewater, such as chemical treatment, physical treatment, ion exchange, electrocoagulation and biological treatment. It is a fact that not a single treatment technique is effective for industrial effluent treatment. In this study, the physicochemical technique was used to remove the major pollutants as per Sindh Environmental Protection Agency (SEPA) effluent standards that include Chemical Oxygen Demand (COD), Biological Oxygen Demand (BOD), Total Suspended Solid (TSS) and Oil & Grease content. In these techniques e.g. chemical coagulation ferric chloride (FC) and poly aluminum chloride (PAC) coupled with polyvinyl alcohol (PVA), with different doses were used for achieving the optimum results. The best results were observed for COD, BOD, TSS and Oil & Grease reduction by FC and PAC dosing 180 mg/300 ml coupled with 45 mg/300 ml PVA. Further, it was also observed that the FC removal efficiency in slightly acidic to neutral medium (pH = 6–7) for COD (97.5%) and BOD (97.5%) is higher than PAC. However, PAC does perform well in slightly neutral to basic medium (pH = 7.5–8) than FC for the removal of Oil & Grease (95.3%) and TSS (97.4%) from the sugarcane effluent.

13

Physico-mechanical and thermal properties of thermoplastic poly(vinyl alcohol) modified thermosetting urea formaldehyde resin

Sultana Shahin, Mannan Mehedi, Abedin Md. Jaynal, Islam Zahidul, Nur Husna Parvin, Samaddar Purabi Rani

Advances in Materials Science

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2021

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Vol. 21, nr 4(70)

53--66

EN

Urea formaldehyde (UF) resins are brittle and to improve their tensile properties poly(vinyl alcohol) (PVA) has been used to modify the UF resin. An easy improved procedure was developed to make PVA modified UF resin on the basis of conventional synthesis of UF resin. Prepolymer of UF was mixed with different weight percentages of PVA (1-5%) to synthesize modified UF resin which can be used to make adhesive for forest products. Both UF and modified UF resins were characterized by FTIR, physico-mechanical and thermal properties analyses. Modified UF resin containing 2 wt. % PVA exhibited better results than the UF.

14

Otrzymywanie polimerowych kompozycji hydrożelowych modyfikowanych kwasem cytrynowym oraz badanie ich wybranych właściwości

Okulska-Bożek M., Płachta B., Jabłońska E., Szczerba J., Pyrka S.

Przetwórstwo Tworzyw

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2018

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T. 24, Nr 4 (184)

17--25

PL

Otrzymano szereg biomateriałów hydrożelowych, zawierających w swej strukturze kwas cytrynowy (CA), metodą dwuetapową. W pierwszym etapie przeprowadzano chemiczną modyfikację poli(alkoholu winylowego) (PVA) przy użyciu CA w obecności kwasu p-toluenosulfonowego jako katalizatora. Celem modyfikacji było wprowadzenie do łańcuchów hydrofilowego polimeru sieciujących wiązań i mostków estrowych. W etapie drugim otrzymywano materiały hydrożelowe, bazując m.in. na zmodyfikowanym PVA. Wytwarzano materiały, zawierające przenikające się wzajemnie sieci polimerowe, metodą polimeryzacji rodnikowej kwasu akrylowego i/lub metakrylanu metylu, inicjowanej przy użyciu 2,2'-azobis(izobutyronitrylu) (AIBN), prowadzonej w roztworze wodnym zmodyfikowanego PVA. Zbadano rozpuszczalność sporządzonych materiałów hydrożelowych w wybranych rozpuszczalnikach oraz oceniono ich zdolność do pęcznienia (sorpcji wody) w procesie inkubacji próbek w wodzie destylowanej oraz roztworach NaCI, HCl i mocznika, symulujących płyny fizjologiczne ludzkiego organizmu. Obserwowano szybkość desorpcji wody podczas suszenia próbek w temp. 37°C. Na podstawie uzyskanych wyników oceniono, że materiały tego typu mogłyby znaleźć zastosowanie jako hydrożel owe powłoki w technologii leków lub superabsorbenty w wyrobach higienicznych.

EN

The series of hydrogel materials containing ciric acid (CA) in their structure were prepared by the two-step route. In the first step the chemical modification of poly(vinyl alcohol) was conducted by using appropriate amount of CA in the presence of p-toluenesulphonic acid as the catalyst. The introduction of the crosslinking ester fragments to the hydrophilic polymer chains was the aim of this modification. In the second step hydrogels on the base of modified PVA were obtained. Materials with interpenetrating polymer networks were prepared during radical polymerization of acrylic acid and/or methyl metacrylate initiated by 2,2 '-azobis(isobutyronitrile) (AIBN), conducted in water solution of modified poly(vinyl alcohol). The solubility of prepared hydrogel materials for selected solvents was tested. The swelling ratio ability to sorption of water under soaking the samples of hydrogels in distilled water and NaCl, HCl and urea solutions, simulating physiological liquids of human organism, was examined. The rate of water desorption during the process of hydrogel samples drying at the temperature of 37°C was observed. The obtained results showed that such materials could be used as hydrogel layers in the technology of drugs or as superabsorbents in hygienic products.

15

Grafika artystyczna od ogółu do szczegółu. Teoria/Praktyka/Parametryzacja 2018

Kukawski T. M.

Architecturae et Artibus

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2018

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Vol. 10, no. 4

55--68

PL

Dwa rozdziały artykułu są rozważaniami o sztuce i grafice ostatnich lat w kontekście obrazów artystycznych i medialnych. Dwa następne opisują teoretyczne i praktyczne doświadczenia z realizacji prac artystycznych w roku 2018 (wraz ze wskaźnikami parametryzującymi). Kolografia jako technika graficzna jest metodą nieznaną, mimo swej ponad stuletniej historii występowania w praktyce graficznej i mimo ponad pięćdziesięciu lat od momentu ukucia nazwy przez amerykańskiego artystę Glena Alpsa. Sama nazwa jest różnie zapisywana, etymologicznie poprawna jest kolagrafia, ale występują nazwy: kolografia, kolograf, kolagrafia, kolagraf, czasem grafika strukturalna. Dostępne definicje i opisy techniki zebrane i zestawione ze sobą dają wystarczająco jasny obraz sprzeczności i bałaganu terminologicznego w tym obszarze. Autorska technologia kolografii Tomasza Kukawskiego pozwala określić technikę wedle standardów podręcznikowych pokrewnych opisom i praktyce innych, klasycznych technik graficznych. W tym przypadku najkrótszy opis brzmi: matryca kolograficzna jest matrycą reliefową; jest fizyczną (analogową) formą zapisu informacji obrazowej; drukowana może być jako druk wklęsły lub wypukły lub jako oba jednocześnie; może być stosowana w dowolnych połączeniach druku wklęsłego i wypukłego oraz kompilowana z dowolnymi technikami obydwu ww. rodzajów druku. Materiał matrycy kolograficznej to: tektura i papiery impregnowane i klejone za pomocą polialkoholu winylowego PVA, który w swojej masie jest również podstawowym materiałem tworzącym matrycę.

EN

Two chapters of the article are reflections on the condition ofart and printmaking of recent years in the context of art and media.. The next two describe the theoretical and practical experience of the implementation of artistic works in 2018 (along with parameterization indicators). Colography (as a graphic technique) is still a unknown method , despite its: more than century-old history of practice, and 58 years after giviing the name by Glen Alps. The term is variously using: colography, colograph , colagraphy , colagraph , sometimes structural graphics. Available definitions and descriptions of techniques only enlarge a terminological mess. Colography Thomas Kukawski’s method allows to specify the technique according to standard descriptions and practice similar to other classic graphic techniques. In this case, the shortest description is: colographic matrix is a relief matrix; is the physical ( analog ) form of notation; can be printed as intaglio or relief printing, or both at the same time; can be used in many combinations and compiled with any techniques of both print types . Matrix material is: cardboard and paper glued impregnated with polyvinyl alcohol PVA, which in its mass is also an essential matrix-forming material.

16

Rheological properties of compositions based on modified polyvinyl alcohol

Krasinskyi V., Suberlyak O., Antonuk V., Jachowicz T.

Advances in Science and Technology. Research Journal

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2017

|

Vol. 11, no 3

304--309

EN

The paper is dedicated to development of a method for producing structured waterproof films based on polyvinyl alcohol (PVA) and montmorillonite-polyvinylpyrrolidone mixture (MPM) to research the impact of borax, pH-environment and MPM content on the rheological properties PVA solutions and water absorption capacity of films based on them. In the experimental studies it has been established that the montmorillonite- polyvinylpyrrolidone mixture significantly effects on viscosity the characteristics of the solution polyvinyl alcohol provided their mixing in the ultrasonic field. Composition of traces of sodium tetraborate in the aqueous solution eminent by the highest rates of viscosity. Also, designed compositions have a considerable influence on pH at the viscosity, particularly compositions obtained in weakly alkaline environment with higher values of relative viscosity than compositions obtained in neutral and acidic environments. Simultaneously, the best water resistance and mechanical properties of films is obtained in an acidic environment. The optimum from the standpoint of durability and water resistance is a composition of PVA:MPM = 12:1 and because, depending on the contents of the MPM and pH characteristics films based on PVA can be adjusted over a wide range, which would expand the scope.

17

Natural modified starch and synthetic sizes in function of characteristics of sized yarn

Kovačević S., Dorđević S., Dorđević D.

Fibres & Textiles in Eastern Europe

|

2016

|

Vol. 24, no. 1 (115)

56--66

EN

The aim of this study was to investigate the changes in properties of yarn made by sizing with synthetic and natural modified corn starch. Different procedures for obtaining modified natural (corn) starch and various combinations of natural and synthetic sizes were used to explore the differences in the properties of sized yarn. The sizing process was carried out under with constant conditions in a newly developed laboratory sizing machine on twisted cotton yarns of 20×2 tex and 30×2 tex. According to the results obtained, yarn sized with synthetic sizes has substantially better properties than those which are naturally sized with modified starch. However, sometimes these differences are not significant or they do not exist at all. Twisted yarn is not always necessary in sizing in order to increased its strength but rather to protect the surface from wear and refine projecting fibers; in this case natural modified starch from corn can meet the requirements. The significance of this research is the application of natural sizes, improvement of the sizing process with natural modified sizes using new achievements in the development of the sizing process, and thus creating a positive environmental and economic impact.

PL

Celem pracy było zbadanie zmian właściwości przędz preparowanych preparacjami syntetycznymi i z naturalnie modyfikowanej skrobi. Proces nanoszenia preparacji przeprowadzono przy zachowaniu stałych warunków nowo zbudowanej laboratoryjnej maszynie. Obrabiano skręcane przędze bawełniane o masie liniowej 20 × 2 tex i 30 × 2 tex. Zgodnie z otrzymanymi wynikami przędze preparowane preparacją syntetyczną miały zdecydowanie lepsze parametry od przędz z preparacją opartą na modyfikowanej skrobi. Jednakże czasami różnice te nie determinują konieczności zastosowania preparacji syntetycznej zwłaszcza w sytuacji kiedy nie jest wymagane uzyskanie maksymalnej wytrzymałości a istotne są elementy ochrony środowiska i koszty produkcji.

18

Determination of material parameters of isotropic and anisotropic hyper-elastic materials using boundary measured data

Hajhashemkhani M., Hematiyan M. R.

Journal of Theoretical and Applied Mechanics

|

2015

|

Vol. 53 nr 4

895—910

EN

Identification of mechanical properties of isotropic and anisotropic materials that demonstrate non-linear elastic behavior, such as rubbers and soft tissues of human body, is critical for many industrial and medical purposes. In this paper, a method is presented to obtain the mechanical constants of Mooney-Rivlin and Holzapfel hyper-elastic material models which are employed to describe the behavior of isotropic and anisotropic hyper-elastic materials, respectively. By using boundary measured data from a sample with non-standard geometry, and by using an iterative inverse analysis technique, the material constants are obtained. The method uses the results of different experiments simultaneously to obtain the material parameters more accurately. The effectiveness of the proposed method is demonstrated through three examples. In the two first examples, the simulated measured data are used, while in the third example, the experimental data obtained from a polyvinyl alcohol sample are used.

19

Studies of the properties of green ceramic proppants obtained by spray drying method

Wiśniewski P., Małek M., Szymańska J., Mizera J., Kurzydłowski K. J.

Journal of Achievements in Materials and Manufacturing Engineering

|

2015

|

Vol. 73, nr 2

124--127

EN

Purpose: The aim of this work was to elaborate composition and preparation method of ceramic granulates. In this paper results of properties studies of obtained proppants are presented. Design/methodology/approach: The properties: bulk density, roundness coefficient, grain size and also structure and morphology of proppants were investigated by Scanning Electron Microscopy (SEM) with Energy Dispersive Spectroscopy (EDS). The results indicate that composition of raw materials and type of binder have an essential effect on proppants properties in green state. Findings: The influence of polymeric binder was examined. Two types of green proppants obtained in spray dryer without binder and with poly(vinyl alcohol) in amount of 5 wt. % with respect to the powder were tested. Research limitations/implications: The main limitations are: proppants compositions and complex process to produce of them in spray dryer. Due to processing requirements and conditions in formations, proppants should be characterized by suitable physico-mechanical properties. Practical implications: Proppants are ceramic materials applied in hydraulic fracturing during extraction of shale gas. Granulates pumped with liquid into the deposit cause destruction of the rock structure. The role of proppants is to avoid closing of formed pores and as result enable gas migration from the deposit. Ceramic proppants have been produced by the spray drying method with the use of naturally occurring raw materials i.e. clay, bauxite and kaolin Originality/value: This is one of first research to preparing ceramic proppants in spray dryer using developed slurries contains Polish raw materials. The presented method for the preparation of ceramic proppants is an alternative technique in relation to the mechanical granulation.

20

Preparation and Study of Some Electrical Properties of PVA-Ni(NO3)2 Composites

Salman S.A., Bakr N. A., Mahmood M.H.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 40

36--42

EN

The aim of this paper is to prepare and study the (D.C.) electrical conductivity of (PVA-Ni(NO₃)₂) composites at different temperatures. For that purpose, PVA films with Ni(NO₃)₂ salt additive were prepared with different concentrations 2, 4, 6, 8 and 10 wt. % and with thickness of 45μm by using casting technique. The experimental results for PVA-Ni(NO₃)₂) films show that the (D.C.) electrical conductivity increased with increasing the filler content and the temperature, and the activation energy was decreased with increasing the filler content.