Wyniki wyszukiwania dla: CELLULOSE ACETATE
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Statistical evaluation of the changes in cellulose properties caused by the stepwise solvent exchange and esterification
PublikacjaThe objective of the research was to empirically confirm the changes in cellulose reactivity caused by the pre-treatment with solvents of different polarity. Therefore, 5 solvents varying in their polar component of surface tension from 0 to 4.6 mN/m were chosen. Their impact on the biopolymer properties was carefully analysed concerning chemical structure, crystallinity and surface characteristics. It was revealed that the length...
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Synthesis of bimetallic Co–Pt/cellulose nanocomposites for catalytic reduction of p-nitrophenol
PublikacjaIn this study, bimetallic nanoparticles (NPs) of Co–Pt anchored on cellulose nanofibers (CNFs) for catalytic applications were synthesized via a sonochemical approach. The electro-spinning technique was employed for the synthesis of CNFs from cellulose acetate. The thorough characterization of synthesised Co–Pt/CNF nanocomposites was performed with the help of scanning electron microscopy (SEM), Fourier transform infra-red (FT-IR)...
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Bio‐polyols synthesized by liquefaction of cellulose: Influence of liquefaction solvent molecular weight
PublikacjaCurrently, the plastics industry including polyurethanes is based on the use of petrochemicals. For this reason, scientists are looking for new types of renewable resources for the substitution of petrochemical substances. This work aims to evaluate the effect of polyethylene glycols (PEG) with different molecular mass impact on properties of bio-based polyols synthesized via biomass liquefaction of cellulose. To date, research...
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<i>N,N</i>'-diphenylthiourea acetone monosolvate
PublikacjaIn the title compound, C13H12N2S·C3H6O, the phenyl rings of the thiourea molecule are in syn and anti positions in relation to the C=S bond. Two molecules are connected by N-HS=C hydrogen bonds into a centrosymmetric dimer. An additional N-HO=C hydrogen bond to the acetone solvent molecule and some weak C-H interactions reinforce the crystal structure.
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Properties of Barium Cerate-Zirconate Thin Films
PublikacjaIn this work, we review several experimental results showing the electrical properties of barium cerate-zirconate thin films and discuss them in view of the possible influence of various factors on their properties. Most of the presented Ba(Ce, Zr, Y)O3 thin films were formed by the pulsed laser deposition (PLD) technique, however thin films prepared using other methods, like RF magnetron sputtering, electron-beam deposition, powder...
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Tetraalkylammonium acetates and tetraalkylammonium tetrafluoroborates as new templates for room-temperature synthesis of mesoporous silica spheres
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Martini 3 Model of Cellulose Microfibrils: On the Route to Capture Large Conformational Changes of Polysaccharides
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Erratum to: Coarse-grained model of the native cellulose Iα and the transformation pathways to the Iβ allomorph
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Elastic moduli of biological fibers in a coarse-grained model: crystalline cellulose and β-amyloids
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Bacterial cellulose as a support for yeast immobilization – Correlation between carrier properties and process efficiency
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Potential of Novel Bacterial Cellulose Dressings Chemisorbed with Antiseptics for the Treatment of Oral Biofilm Infections
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Potato Juice, a Starch Industry Waste, as a Cost-Effective Medium for the Biosynthesis of Bacterial Cellulose
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Structure, morphology and mechanical behaviour of novel bio-based polyurethane composites with microcrystalline cellulose
PublikacjaThe aim of this work was to obtain bio-based polyurethane composites using biocomponents such as, bio-glycol, modified natural oil-based polyol, and microcrystalline cellulose (MCC). The prepolymer method was used to prepare the bio-based polyurethane matrix. Prepolymer synthesised from 4,4’-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 75% wt. commercial polyether and 25% wt. hydroxylated soybean oils (H3)...
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A mixture of cellulose production waste with municipal sewage as new material for an ecological management of wastes
PublikacjaChemical contaminants present in cellulose production waste and municipal sewage sludge condition the necessity to treat these wastes before they are introduced into the environment. Environmental use of the these wastes appears to be justified owing to the content of organic substances as well as the considerable fertilising value. The aim of the study was to assess chemical composition and ecotoxicity of cellulose production...
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Assessment of the usefulness of bacterial cellulose produced by Gluconacetobacter xylinus E25 as a new biological implant
PublikacjaBionanocellulose (BNC) is a clear polymer produced by the bacterium Gluconacetobacter xylinus. In our current study, “Research on the use of bacterial nanocellulose (BNC) in regenerative medicine as a function of the biological implants in cardiac and vascular surgery”, we carried out material analysis, biochemical analysis, in vitro tests and in vivo animal model testing. In stage 1 of the project, we carried out physical and...
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Enzymatic and Chemical Cross-Linking of Bacterial Cellulose/Fish Collagen Composites—A Comparative Study
PublikacjaThis article compares the properties of bacterial cellulose/fish collagen composites (BC/Col) after enzymatic and chemical cross-linking. In our methodology, two transglutaminases are used for enzymatic cross-linking—one recommended for the meat and the other proposed for the fish industry—and pre-oxidated BC (oxBC) is used for chemical cross-linking. The structure of the obtained composites is characterized by scanning electron...
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Insights into Compatibilization of Poly(ε-caprolactone)-based Biocomposites with Diisocyanates as Modifiers of Cellulose Fillers
PublikacjaThis study aimed to analyze the impact of cellulose fillers’ modification with diisocyanates on the performance of composites based on the poly(ε-caprolactone) (PCL) matrix. Four most commonly used diisocyantes (isophorone, hexamethylene, toluene, and methylene diphenyl) were applied as modifiers of cellulose fillers (5 and 15 wt% per mass of filler). Modified fillers were introduced in the amount of 30 wt% into the PCL matrix....
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Cellulose Nanofibers Isolated from the Cuscuta Reflexa Plant as a Green Reinforcement of Natural Rubber
PublikacjaIn the present work, we used the steam explosion method for the isolation of cellulose nanofiber (CNF) from Cuscuta reflexa, a parasitic plant commonly seen in Kerala and we evaluated its reinforcing efficiency in natural rubber (NR). Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Thermogravimetric analysis (TGA) techniques...
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Electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations of ethyl acetate
PublikacjaThe high-resolution vacuum ultraviolet photoabsorption spectrum of ethyl acetate, C4H8O2, is presented over the energy range 4.5−10.7 eV (275.5−116.0 nm). Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Also, the photoabsorption cross sections...
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Isobutyl acetate: electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations
PublikacjaThe high-resolution vacuum ultraviolet photoabsorption spectrum of isobutyl acetate, C6H12O2, is presented here and was measured over the energy range 4.3–10.8 eV (290–115 nm). Valence and Rydberg transitions with their associated vibronic series have been observed in the photoabsorption spectrum and are assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. The measured...
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Results of nanoindentation, XRD and microscopic studies of bacterial cellulose
Dane BadawczeThe archive contains the results of research on BNC bacterial biocellulose, which was modified in two ways. When BNC was synthesized, it was subjected to in situ modification involving the addition of hyuloronic acid to the bacterial medium. The second way of ex situ modification consisted of soaking the BNC in water and then convectionally drying it...
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Optimization of microstructure and properties of acceptor-doped barium cerate
PublikacjaThe presented research concerns acceptor doped barium cerate and the attempts of improvement of its production method that would allow obtaining the solid electrolyte characterized by the particular properties. The authors suggest combining two production methods, molten salt synthesis and self-combustion, in order to achieve the compound material that has some of the advantages of both of the initial methods. An impact of nickel...
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A whole-cell immobilization system on bacterial cellulose for the paracetamol-degrading Pseudomonas moorei KB4 strain
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Improving carboxymethyl cellulose edible coating using ZnO nanoparticles from irradiated Alternaria tenuissima
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Carboxymethylated starch and cellulose derivatives-based film as human skin equivalent for adhesive properties testing
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Intensification of bacterial cellulose production process with sequential electromagnetic field exposure aided by dynamic modelling
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An efficient method of Yarrowia lipolytica immobilization using oil- and emulsion-modified bacterial cellulose carriers
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Development and biological evaluation of Ti6Al7Nb scaffold implants coated with gentamycin-saturated bacterial cellulose biomaterial
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Significant enhancement of citric acid production by Yarrowia lipolytica immobilized in bacterial cellulose-based carrier
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Chemical structure, thermal and mechanical characterization of bio-based polyurethane composites filled with microcrystalline cellulose
PublikacjaOver the past several decades, the interest in replacing the synthetic components used in the production of polymers and composites with their natural counteparts has been growing. Biocomposites belong to the group of materials produced with the use of renewable raw materials. There has been a recent surge of interest in the industrial applications of composites containing natural fibres reinforced with biopolymers. Biopolymers...
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Bacterial cellulose in the field of wound healing and regenerative medicine of skin: recent trends and future prospectives
PublikacjaIn this overview, we focused on the bacterial cellulose (BC) applications, described in recently published scientific papers, in the field of skin regenerative medicine and wound care industry. Bacterial cellulose was proven to be biocompatible with living tissues. Moreover, its mechanical properties and porous structure are considered to be suitable for biomedical applications. It is due to the fact that porous structure of bacterial...
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Biopolyols obtained via crude glycerol-based liquefaction of cellulose: their structural, rheological and thermal characterization
PublikacjaIn this work lignocellulose biomass liquefaction was used to produce biopolyols suitable for the manufacturing of rigid polyurethane foams. In order to better evaluate the mechanism of the process, pure cellulose was applied as a raw material. The effect of time and temperature on the effectiveness of liquefaction and the parameters of resulting biopolyols were characterized. The prepared materials were analyzed in terms of their...
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Chitosan and polyvinyl alcohol nanocomposites with cellulose nanofibers from ginger rhizomes and its antimicrobial activities
PublikacjaThe inhibitory effect of 5% GNF bionanocomposites against Bacillus cereus, Escherichia coli, Staphylococcus aureus and Salmonella typhimurium indicated good antibacterial activity of the nanocomposites due to the addition of GNF in the biopolymer matrices. The use of GNF will help to increase the economic values of agricultural waste and the characteristic properties of GNF derived bionanocomposites could be possibly used in medical...
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Compatibility of Sustainable Mater-Bi/poly(ε-caprolactone)/cellulose Biocomposites as a Function of Filler Modification
PublikacjaDespite their popularity and multiplicity of applications, wood–polymer composites (WPCs) still have to overcome particular issues related to their processing and properties. The main aspect is the compatibility with plant-based materials which affects the overall performance of the material. It can be enhanced by strengthening the interfacial adhesion resulting from physical and/or chemical interactions between the matrix and...
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Elucidating the impact of enzymatic modifications on the structure, properties, and applications of cellulose, chitosan, starch and their derivatives: a review
PublikacjaPolysaccharides, as one of the most prominent natural biopolymers, display numerous biological activities and industrial applications. Nevertheless, some polysaccharides lack biological properties or display weak biological activities. Besides, practical usages of polysaccharides still remain challenging because of their poor solubility and inappropriate hydrophilic/hydrophobic balance. Hence, enzymatic or chemical modifications...
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Hydrogen Bonds in Blends of Poly(N-isopropylacrylamide), Poly(N-ethylacrylamide) Homopolymers, and Carboxymethyl Cellulose
PublikacjaRecently, it was reported that the physical crosslinking exhibited by some biopolymers could provide multiple benefits to biomedical applications. In particular, grafting thermoresponsive polymers onto biopolymers may enhance the degradability or offer other features, as thermothickening behavior. Thus, different interactions will affect the different hydrogen bonds and interactions from the physical crosslinking of carboxymethyl...
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Microcrystalline Cellulose Management in the Production of Poly(ether-urethane)s- Structure, Morphology, and Thermal Characteristic
PublikacjaIn response to the demand of polymer industry for reducing the use of synthetic chemicals, eco-friendly materials are investigated. In the presented study, bio-based poly(ether-urethane)s were prepared by using microcrystalline cellulose (MCC) and polyether polyol and 1,3-propanediol derived from corn sugar. A step towards sustainability was taken by incorporating bio-based compounds and cellulose, consequently, bio-waste are utilized...
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Ground Tire Rubber Modified by Ethylene-Vinyl Acetate Copolymer: Processing, Physico-Mechanical Properties, Volatile Organic Compounds Emission and Recycling Possibility
PublikacjaGround tire rubber (GTR) was reclaimed and modified with 10 phr of ethylene-vinyl acetate copolymer via low-temperature extrusion process. Processing, physico-mechanical properties, volatile organic compounds emission, and recycling possibility were investigated. In order to better understand the impact of used modifiers, their efficiency was compared with transpolyoctenamer, which is an additive that is commercially dedicated...
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Experimental investigation of two-phase thermosyphon heat exchanger charged with acetone
PublikacjaThis paper presents thermal characteristics of prototype of a two-phase thermosyphon heat exchanger (TPTHEx) charged with acetone as a working fluid. The TPTHEx consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. The tested TPTHEx operates in a vacuum. Therefore, the working liquid is boiled...
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Proton affinity and proton transfer energy for selected organic molecules
PublikacjaThe Hartree-Fock method in 6-311G** molecular orbitals basis set has been applied to calculations of proton affinities and proton transfer reaction energies for water, methanol, acetaldehyde, ethanol, acetone, acetic acid, methyl acetate and ethyl acetate.
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Attraction of Moths of Two Noctuidae Species to Field Traps Baited With a Mixture of two to three Homologous Acetates in Poland
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Effect of Soybean or Linseed Oil With RRR-D-α-Tocopherol or Dl-α-Tocopherol Acetate on Quality Characteristics and Fatty Acid Profile of Turkey Meat
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Glycoside hydrolase (PelAh) immobilization prevents Pseudomonas aeruginosa biofilm formation on cellulose-based wound dressing
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Application of bacterial cellulose experimental dressings saturated with gentamycin for management of bone biofilm in vitro and ex vivo
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Correlation between type of alkali rinsing, cytotoxicity of bio-nanocellulose and presence of metabolites within cellulose membranes
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The cellulose fibers functionalized with star-like zinc oxide nanoparticles with boosted antibacterial performance for hygienic products
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Chlorine-free extraction and structural characterization of cellulose nanofibers from waste husk of millet (Pennisetum glaucum)
PublikacjaThis study aims to extract cellulose nanofibers (CNFs) from a sustainable source, i.e. millet husk, which is an agro-waste worthy of consideration. Pre-treatments such as mercerisation, steam explosion, and peroxide bleaching (chlorine-free) were applied for the removal of non-cellulosic components. The bleached millet husk pulp was subjected to acid hydrolysis (5% oxalic acid) followed by homogenization to extract CNFs. The extracted...
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Structural changes of bacterial cellulose due to incubation in conditions simulating human plasma in the presence of selected pathogens
PublikacjaBacterial nanocellulose (BNC) is a natural biomaterial with a wide range of medical applications. However, it cannot be used as a biological implant of the circulatory system without checking whether it is biodegradable under human plasma conditions. This work aimed to investigate the BNC biodegradation by selected pathogens under conditions simulating human plasma. The BNC was incubated in simulated biological fluids with or...
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Influence of ligno-cellulosic particles on tribological properties of boards
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OBSERVATION OF THE THERMOSIPHON EFFECT IN THE CIRCULATION OF ACETONE AS WORKING FLUID IN MODERN COOLING SYSTEM
Publikacjaplants or computer server rooms has led to the demand for new and reliable methods for electronic cooling. Because of bigger and bigger power levels and miniaturization of the electronic devices, lack of free space in such a high heat flux. The increasing integration of electronic logy that supposed to be designed for high thermal performance, low mass, and able to work in harsh environments. In this paper presented a prototype...