Lídia K. Lazzari^*, Vitória B. Zampieri, Ademir J. Zattera, Camila Baldasso

Journal of Renewable Materials, Vol.7, No.3, pp. 227-234, 2019, DOI:10.32604/jrm.2019.00024

Abstract This work aimed at analyzing the petroleum adsorption capacity and the compressive strength of cellulose cryogels produced with the addition of 4 and 8% (w/w) sodium hydroxide (NaOH). Cryogels were produced from a 1.5% (m/m) suspension of cellulose microfibers, which originated from Pinus elliotti, in distilled water. The addition of NaOH increased the compression strength of cryogel by 30% when compared to cryogel without the reagent. Due to the 50% decrease in volume, the cryogel FLNB-8h (8% NaOH) has its petroleum adsorption capacity decreased in average by 58%, whereas the FLNB-4 (4% NaOH) cryogel had it only by 14%. The… More >

Yasemin Kaptan, M.Sc.^1,*, Yüksel Avcıbaşı-Güvenilir¹

Journal of Renewable Materials, Vol.6, No.6, pp. 619-629, 2018, DOI:10.32604/JRM.2018.00142

Abstract Surface-modified rice husk ash was used as an inorganic support material for immobilization of Candida antarctica lipase B. (3-aminopropyl) trimethoxysilane was used for surface modification. Immobilization of CALB was performed via both physical adsorption and cross-linking. PCL synthesis was carried out by using these immobilized enzymes, free enzyme and Novozyme 435®. Molecular weight distribution of polymer samples was obtained by gel permeation chromatography (GPC) and chain structures of the polymer samples were observed by hydrogen nuclear magnetic resonance (1H-NMR). The highest monomer conversion is generally obtained by using cross-linked enzyme, around 90%. PDI values for all polymer samples were approximately… More >

Lars Helmlinger¹, Yejun Zhu¹, Julia Gensel¹, Thomas Neumeyer¹, Stefan Thäter², Franziska Strube², Christoph Bauer², Bernd Rosemann², Volker Altstädt^1*

Journal of Renewable Materials, Vol.6, No.3, pp. 219-225, 2018, DOI:10.7569/JRM.2017.634161

Abstract Due to a lack of technology, smaller breweries simply dump excess CO2 into the atmosphere, fueling the greenhouse effect and global warming. State-of-the-art CO2 capture technologies using nanofibrillated cellulose are expensive and require laborious freeze-drying. Consequently, there is a high demand for affordable alternatives in order to reduce the environmental impact in this industry sector. This work describes a novel route for a quick and cost-efficient synthesis of amine-functionalized cellulose pellets by a surfactant-assisted steam explosion process. Typical values with this method were porosity of 92% and density of 67 g/cm³. Investigations on polyethylenimine (PEI) content and distribution revealed a… More >

Sijing Zhang^1*, Fengjiao Ao¹, Yongping Wang², Junxue Zhao³, Yongliang Ji¹, Shuangli Chen¹

Journal of Renewable Materials, Vol.6, No.1, pp. 102-116, 2018, DOI:10.7569/JRM.2017.634154

Abstract A novel biosorbent was synthesized by grafting bisthiourea (BTU) on a silk sericin (SS) matrix. This biosorbent was denoted as BTU-SS and characterized by Fourier transform infrared spectroscopy (FTIR), zeta potential measurements, elemental analysis, and X-ray photoelectron spectroscopy (XPS). As revealed by the adsorption experiments, both BTU-SS and SS showed low affinity towards coexisting base metallic ions in Ag(I)-Cu(II)-Zn(II)-Ni(II)-Pb(II) electronic waste leachate mixtures, while their adsorption capacities towards Ag(I) reached 30.5 and 10.4 mg·g–1 at a pH of 5.0, respectively. BTU-SS showed higher selectivity towards Ag(I) than SS, as revealed by the Ag(I) partition coefficients between the biosorbents and the… More >

Purnendu, Soumitra Satapathi^*

Journal of Renewable Materials, Vol.5, No.2, pp. 96-102, 2017, DOI:10.7569/JRM.2016.634134

Abstract Graphene-based 3D porous xerogel was designed through molecular self-assembly of graphene oxide on chitosan matrix and its application in removal of different heavy metal ions from wastewater was investigated. The synthesized xerogel was characterized through FTIR, SEM, XRD and BET surface area analysis. Heavy metal ions, including Pb(II), Cd(II), and Hg(II), were removed from wastewater using this graphene-chitosan (GO-Cs) xerogel and the removal efficiency was monitored through inductively coupled plasma mass spectrometry (ICP-MS). The effect of GO-Cs composition and pH on adsorption efficiency as well as the kinetics of adsorption was studied in detail. The study exhibited that this xerogel… More >

Kentaro Doi^1,2, Ikumi Onishi¹, Satoyuki Kawano^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.2, pp. 113-136, 2011, DOI:10.3970/cmes.2011.077.113

Abstract Hydrogen technologies are currently one of the most actively researched topics. A lot of researches have tied to enhance their energy conversion efficiencies. In the present study, numerical analyses have been carried out focusing on hydrogen-storage carbon materials which are expected to realize high gravimetric and volumetric capacities. In particular, dissociative adsorption processes of H₂ molecules above graphene surfaces have been investigated by ab initio molecular dynamics. The present results indicate that a steric graphene surface plays an important role in enhancing the charge transfer which induces dissociation of H₂ and adsorption of H atoms on the surface. The dissociation… More >

Zhen Yang¹, Xingsheng Gu², Xiaoyi Liang^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.74, No.3&4, pp. 161-182, 2011, DOI:10.3970/cmes.2011.074.161

Abstract Mesoporous carbons are synthesized by organic-organic self-assembly of triblock copolymer F127 and a new type of carbon precursor as resorcinol-furfural oligomers. Some factors will impact the mesoporous carbons pore structure and properties were studied. The main factors, such as the ratio of triblock copolymer F127 and oligomers, degree of polymerizstry of resorcinol-furfural oligomers, the ratio of resorcinol-furfural oligomers - F/R, and their mutual relations were identified. Aimed at balancing the complex characteristic of mesoporous structure and adsorption properties, a classification and optimization model based on support vector machine is developed. The optimal operation conditions of Barret-Joyner-Halenda (BJH) adsorption cumulative volume… More >

Yan Zhang¹, Shengping Shen¹

CMC-Computers, Materials & Continua, Vol.8, No.1, pp. 17-22, 2008, DOI:10.3970/cmc.2008.008.017

Abstract In this paper, an existed model for adsorption-induced surface stress is modified with physical clarity, based on the equilibrium of force. In the proposed multiscale model, a four-atom system is used, instead of the existed three-atom system which did not consider the force equilibrium. By analyzing the force state of an atom, the thickness of the first layer atoms can be determined. Thus, the proposed model does not need to determine the layer-thickness by experiments or artificially. The results obtained from the proposed model agree very well with the experimental data. This paper is helpful to investigate the atomistic theory… More >