Elizabeth J. Jacobo^1,#,*, Adriana M. Rodríguez^2,#

Phyton-International Journal of Experimental Botany, Vol.93, No.6, pp. 1179-1202, 2024, DOI:10.32604/phyton.2024.050928

Abstract The Flooding Pampa grasslands are the last remnant of the Rio de la Plata grasslands in Argentina. Anthropogenic interventions have led to severe degradation and, as a result, the ecosystem services provided by the grasslands are declining, in terms of provisioning, regulating, and supporting services. We synthesized the existing literature on the ecosystem goods and services provided by these grasslands under grazing in different conditions and conservation status. We found that plant and animal diversity and primary production are the most studied ecosystem services, while climate regulation, water supply, nutrient cycling, meat production and erosion… More >

Yang Xiong^1,2, Jianxin Liu^1,2,*, Xianhao Yi², Bangyan Xiao², Dan Wu², Biao Wu², Chunyu Gao²

Energy Engineering, Vol.121, No.7, pp. 1759-1780, 2024, DOI:10.32604/ee.2024.048536

Abstract In the heterogeneous reservoirs, CO₂ flooding easily leads to CO₂ gas channeling, which can seriously affect sweeping efficiency and reduce oil recovery. After thoroughly investigating the advantages and shortcomings of various CO₂ plugging technologies, this paper focuses on the feasibility of improving conventional water-alternating gas (WAG) through CO₂-responsive gel materials. Based on the different chemical reaction mechanisms between the unique chemical structure and CO₂, changes in the material’s physical and chemical properties can respond to CO₂. The feasibility of utilizing these property changes for CO₂-responsive plugging is explored. Various CO₂-responsive gels and gel nanoparticles have been extensively researched in More >

Xiaoyu Chen^*

Journal of Renewable Materials, Vol.12, No.4, pp. 815-826, 2024, DOI:10.32604/jrm.2024.048470

Abstract A novel core-shell hydrogel bead was fabricated for effective removal of methylene blue dye from aqueous solutions. The core, made of sodium alginate-g-polyacrylamide and attapulgite nanofibers, was cross-linked by Calcium ions (Ca). The shell, composed of a chitosan/activated carbon mixture, was then coated onto the core. Fourier transform infrared spectroscopy confirmed the grafting polymerization of acrylamide onto sodium alginate. Scanning electron microscopy images showed the core-shell structure. The core exhibited a high water uptake ratio, facilitating the diffusion of methylene blue into the core. During the diffusion process, the methylene blue was first adsorbed by More > Graphic Abstract

Susi Susi^1,2,*, Makhmudun Ainuri^3,*, Wagiman Wagiman³, Mohammad Affan Fajar Falah³

Journal of Renewable Materials, Vol.12, No.3, pp. 513-537, 2024, DOI:10.32604/jrm.2024.045586

Abstract Microcrystalline cellulose (MCC) is one of the cellulose derivatives produced as a result of the depolymerization of a part of cellulose to achieve high crystallinity. When implemented in other polymers, high crystallinity correlates with greater strength and stiffnes, but it can reduce the water-holding capacity. The acid concentration and hydrolysis time will affect the acquisition of crystallinity and water absorption capacity, both of which have significance as properties of hydrogel filler. The study aimed to evaluate the properties and select the MCC generated from varying the proportion of hydrochloric acid (HCl) and the appropriate hydrolysis… More > Graphic Abstract

AYÇA BAL ÖZTÜRK^1,2,*, ZEHRA ÖZBA޳, BENGİ ÖZKAHRAMAN⁴, SERKAN EMİK⁵

Journal of Polymer Materials, Vol.36, No.2, pp. 161-173, 2019, DOI:10.32381/JPM.2019.36.02.5

Abstract A functionalized hydrogel composed of 2-(hydroxyethyl) methacrylate (HEMA) and acrylamide (AAm) was synthesized by amination and saponification reactions, respectively, and its functionality was examined for the elimination of copper(II) ions. The maximum adsorption capacity for copper(II) ions was 0.617 mmol g^-1 before saponification, whereas it was 1.2225 mmol g^-1 after saponification. The adsorption data was analyzed with pseudo-first-order (r² =0.8867), intra-particle diffusion (r² =0.9453), Elovich (r²=0.9489) and pseudo-secondorder(r² =0.9999) kinetic models. Based on the adsorption equilibrium experimental data Freundlich(r² =0.9964), Langmuir(r²=0.998) and Dubinin–Radushkevich (D-R) (r² =0.9960) adsorption isotherms provided good fits for all of experimental results. Finally, the datas of More >

FATMA LOUZRI, SADJIA BENNOUR

Journal of Polymer Materials, Vol.37, No.1-2, pp. 55-76, 2020, DOI:10.32381/JPM.2020.37.1-2.5

Abstract Poly(N,N-dimethymethylacrylamide -co-crotonic acid) (P(DMA-CAx)) hydrogels were prepared by free radical polymerization, using N,N- methylenebisacrylamide (NMBA) as cross-linking agent. The synthesized hydrogels were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The effects of comonomer composition and pH of the medium on the swelling behavior of hydrogels were investigated. The obtained results showed that the swelling capabilities of hydrogels increased as crotonic acid content and pH increased. In order to evaluate the controlled release potential of the polymeric matrix, it was loaded with potassium nitrate and ammonium nitrate as fertilizers and the release More >

JALPA V. CHOPDA, DHARMESH B. SANKHAVARA, JIGNESH P. PATEL, P. H. PARSANIA^*

Journal of Polymer Materials, Vol.38, No.1-2, pp. 35-48, 2021, DOI:10.32381/JPM.2021.38.1-2.4

Abstract Conventional curing study of epoxy resin of (2E, 6E)-bis (4-hydroxybenzylidene)-4-methyl cyclohexanone (EMBHBC) was conducted at 140 0 /150 0 C by using 4,4’-diaminodiphenylmethane (DDM),4,4’-diaminodiphenylsulphone (DDS),4-4’-diaminodiphenyl ether (DDE), p-phenylenediamine (PDA), 1,2,3,6-tetrahydrophthalic anhydride(THPA), maleic anhydride (MAH) and pyromellitic dianhydride (PMDA). The gel time for DDS, THPA and DDM hardeners are found considerably longer than those of DDE, PDA, MAH and PMDA systems indicated different reactivity towards curing of EMBHBC. Sol–gel analysis of cured resins was carried out in DMF at room temperature. Diamines cured samples showed 76.3-97.5% gel fractions, while anhydrides cured samples showed 84.6-99.6% gel fractions.… More >

ELIF ANT BURSALI^1,*, DILER ABACI¹, MURAT KIZIL², MURUVVET YURDAKOC¹

Journal of Polymer Materials, Vol.38, No.3-4, pp. 231-245, 2021, DOI:10.32381/JPM.2021.38.3-4.5

Abstract Genipin cross-linked/boron doped starch/polyvinily alcohol (PVA) based hydrogel (SH-GNP-B) was synthesized as a new material having antimicrobial and antioxidant activity. The prepared hydrogel was characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermal Gravimetric Analysis (TGA) and Scanning Electron Microscope (SEM) methods and evaluated for in vitro antimicrobial activities against selected organisms by disc diffusion tests. The antioxidant activity of the prepared hydrogels was evaluated using 2,2-diphenyl-1- picrylhydrazyl radical scavenging assays. Swelling behavior of the hydrogel was also investigated. The synthesized hydrogel was thermally stable and showed pH independent swelling tendency. SH-GNP-B hydrogel More >

PRITI^1,*, RADHA SACHAN², ROLI PURWAR³

Journal of Polymer Materials, Vol.40, No.3-4, pp. 205-214, 2023, DOI:10.32381/JPM.2023.40.3-4.6

Abstract In current research work, we have studied the blending effect of non-mulberry silk fibroin (10% weight/volume basis) and gelatin (20% weight/volume basis) in formic acid. Several blends as SF10G0, SF2G8, SF3G7, SF5G5 and SF0G10 have been made and their rheological behaviour was investigated. The blend solutions were subjected to a steady shear rheological study in the variety of range of shear rates, namely 0.01–500 sec-1 and the viscosities of blend solutions were noticed to decrease in comparison to pure silk solution. The frequency sweep was employed in dynamic rheological tests to determine complex viscosity of More >

Xinyu Zhang¹, Wenjie Xia², Yang Wang^3,4, Liang Wang^1,*, Xiaofeng Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 3047-3061, 2024, DOI:10.32604/cmes.2023.046922

Abstract Graphene aerogel (GA), as a novel solid material, has shown great potential in engineering applications due to its unique mechanical properties. In this study, the mechanical performance of GA under high-velocity projectile impacts is thoroughly investigated using full-atomic molecular dynamics (MD) simulations. The study results show that the porous structure and density are key factors determining the mechanical response of GA under impact loading. Specifically, the impact-induced penetration of the projectile leads to the collapse of the pore structure, causing stretching and subsequent rupture of covalent bonds in graphene sheets. Moreover, the effects of temperature More >