Vol.9, No.8, 2021-Table of Contents

On the Cover

The work presented shows for the first time that at a higher temperature such as 80°C, on top of the known interactions tannin/collagen in leather, there are also a number of covalent linkages and cross-linking of the collagen protein by reaction of the vegetable tannin with the side chains of amino acids carrying –NH2 and –COOH groups most likely contributing to both leather stability and leather shrinkage.
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  • Covalent and Ionic Bonding between Tannin and Collagen in Leather Making and Shrinking: A MALDI-ToF Study
  • Abstract Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract. The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions, if any, did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin. The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight (MALDI ToF) mass spectrometry. Reactions between the two materials did appear to occur, with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the… More
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  • The Preparation and Properties of Starch Based Shape Memory Hydrogel
  • Abstract In this work, the –catechol and –thiol modified starch was prepared by the esterification and amino condensation reaction, then a fully starch based hydrogel was prepared via the thiol-catechol Michael addition reaction. The starch hydrogel gained shape memory behaviors by coordinate with Fe3+ ions at alkaline condition. 1 H-NMR had been used to character the structure of the starch derivatives and its character peaks. The hydrogel’s modulus had also been measured before and after coordinating with Fe3+ ions in linear area and the result showed that both the hydrogel’s storage modulus and loss modulus kept constant in linear area from… More
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  • Green Synthesis of Silver Nanoparticles Using Plectranthus Amboinicus Leaf Extract for Preparation of CMC/PVA Nanocomposite Film
  • Abstract In the present study, the biogenic silver nanoparticles have been synthesized using aqueous leaf extract of Plectranthus amboinicus (PA), which acted as both reducing and stabilizing agents. The PA synthesized silver nanoparticles were blended with carboxymethyl cellulose/polyvinyl alcohol (CMC/PVA) biocomposite. The prepared AgNPs as well as the biogenic AgNPs incorporated CMC/PVA films were investigated using UV-visible spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), scanning electron microscope (SEM), and X–ray diffraction (XRD). The DLS results showed that biogenic AgNPs had the average particle size of 65.70 nm with polydispersity index of 0.44. The surface plasmon resonance of AgNPs, which… More
  • Graphical Abstract

    Green Synthesis of Silver Nanoparticles Using <i>Plectranthus Amboinicus</i> Leaf Extract for Preparation of CMC/PVA Nanocomposite Film
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  • Study on Carbonation Damage Constitutive Curve and Microscopic Damage Mechanism of Tailing Recycled Concrete
  • Abstract To improve the resource utilization of recycled aggregate concrete (RAC) and make use of the unique pozzolanic activation characteristics of iron ore tailing (IOT), the constitutive curves of tailing recycled concrete (TRC) before and after carbonization were analyzed theoretically, experimentally and microscopically. Firstly, according to the experimental data, the damage constitutive and related damage parameters of TRC were theoretically established by Weibull probability distribution function. Secondly, the comprehensive damage parameter b under different working conditions was studied. Finally, the damage mechanism was formed by EDS and SEM. The results showed that the damage constitutive model based on Weibull probability distribution… More
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  • Structure Design and Properties of Three-Layer Particleboard Based on High Voltage Electrostatic Field (HVEF)
  • Abstract In this study, the effects of three different particle sizes of wood wastes (A = –8 + 12 mesh; B = –12 + 20 mesh; C = –20 + 30 mesh) and factory shavings (D) on the properties of particleboard were investigated. According to the test results, three-layer particleboard was designed. Particleboard face layers made with mixture of A, B, and C. The core layer made with D. The ratio of core layer to face layers is 50:50. Three-layer particleboard were fabricated with 12% urea-formaldehyde (UF) resins and three different high voltage electrostatic field intensities (0 kv, 30 kv, 60… More
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  • Preparation and Properties of Polyacrylamide/Sodium Alginate Hydrogel and the Effect of Fe Adsorption on Its Mechanical Performance
  • Abstract

    The preparation and application of functional hydrogels based on natural polysaccharides have always been a hot research topic. In this study, using acrylamide (AM) monomer, N, N'-methylene bisacrylamide (MBA) as cross-linking agent, potassium persulfate (K2S2O8) as initiator, in the presence of natural polysaccharide sodium alginate (SA), the PAM/SA hydrogel was prepared by free radical polymerization. Fourier transform infrared spectroscopy (FT-IR), swelling performance tests, scanning electron microscope (SEM), thermogravimetric analysis (TGA), UV-visible spectrophotometer, mechanical property measurements were carried out to analyze the composition, morphology, and performance of the hydrogels. The swelling behavior, dye adsorption performance, and the mechanical properties of PAM/SA… More

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  • Life Cycle Assessment of Recycling High-Density Polyethylene Plastic Waste
  • Abstract Increasing production and use of various novel plastics products, a low recycling rate, and lack of effective recycling/disposal methods have resulted in an exponential growth in plastic waste accumulation in landfills and in the environment. To better understand the effects of plastic waste, Life Cycle Analysis (LCA) was done to compare the effects of various production and disposal methods. LCA shows the specific effects of the cradle-to-grave or cradle-to-cradle scenarios for landfill, incineration, and mechanical recycling. The analysis clearly indicates that increasing recycling of plastics can significantly save energy and eliminate harmful emissions of various carcinogens and GHGs into the… More
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  • Improving the Unconfined Compressive Strength of Red Clay by Combining Biopolymers with Fibers
  • Abstract To explore an environmentally friendly improvement measure for red clay, the function and mechanism of xanthan gum biopolymer and polypropylene fibers on the strength properties of red clay were investigated by unconfined compressive strength and scanning electron microscopy tests. The test results demonstrated that the contents and curing ages of xanthan gum had significant influences on the unconfined compressive strength of red clay. Compared with untreated soil, 1.5% xanthan gum content was the optimal ratio in which the strength increment was between 41.52 kPa and 64.73 kPa. On the other hand, the strength of xanthan gum-treated red clay increased, whereas… More
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