Green and Sustainable Chemistry

Journal Information
ISSN / EISSN : 2160-6951 / 2160-696X
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 204
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SHERPA/ROMEO
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Latest articles in this journal

Hiromu Okada, Chao Zhao, Yusuke Mizuta, Katsumi Yoshino, Ryuichi Sugimoto
Green and Sustainable Chemistry, Volume 11, pp 9-22; doi:10.4236/gsc.2021.111002

Abstract:
Methyl methacrylate (MMA) was successfully grafted onto cellulose nanofibers (CNFs) at room temperature in an emulsion system using a diethyl(1,10-phenanthroline N1,N10)zinc(II) complex (Phen-DEZ) with oxygen as the radical initiator. The effects of reaction temperature, initiator concentration, and monomer content on the grafting reaction were investigated. The molecular weight of the non-grafted PMMA, which was produced during graft polymerization, was more than 1 million, as determined by size exclusion chromatography. The PMMA-grafted CNFs were analyzed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, which confirmed the grafting of PMMA on the nanofiber surface. The study presents a strategy for the grafting of high-molecular weight PMMA onto CNFs in an emulsion system using Phen-DEZ and O2.
Yutaka Okada, Ryuichi Maeda
Green and Sustainable Chemistry, Volume 11, pp 1-8; doi:10.4236/gsc.2021.111001

Abstract:
Microwave-assisted reactions are an environmentally friendly approach for synthesizing organic compounds. In this study, oximation of acetylferrocene and acetophenone was conducted under both microwave irradiation and conventional heating conditions. Acetylferrocene and acetophenone were subjected to oximation under the two conditions in various solvent mixtures, and the extent of conversion was determined by 1H nuclear magnetic resonance spectroscopy. Microwave irradiation was found to accelerate the rate of oximation of both acetylferrocene and acetophenone. Acceleration of the reaction under microwave irradiation was attributed to the efficient absorption of microwaves by the ferrocene nucleus.
Nurudeen Ishola Mohammed, Nassereldeen Ahmed Kabbashi, Zahangir Alam, Mohamed Elwathig S. Mirghani
Green and Sustainable Chemistry, Volume 11, pp 23-37; doi:10.4236/gsc.2021.111003

Abstract:
Cost of biodiesel is primarily because of factors such as the feedstock, production process and materials. Apparently, the final biodiesel product is a bit expensive compared to fossil diesel fuel. While non-food feedstock of high oil content such as Jatropha curcas has been proposed to reduce the cost due to the feedstock, a promising two-step approach of hydro-esterification can possibly offset the production cost for oil resource with high free fatty acids. Most importantly, optimization of the materials and process is expected to reduce wastage, enhance product purity and generate less wastewater. However, optimizing product generation has been dauntingly elusive because several parameters are needed to be considered holistically. In this study, Response Surface Methodology (RSM) was employed to optimize the yield and conversion of Jatropha biodiesel from J. curcas hydrolysate. An optimum Yield and conversion of 96% was achieved for both responses with an optimum temperature value of 60°C, 4 wt% for catalyst loading for 6 hrs reaction time. Findings imply that optimization study of Jatropha curcas hydrolysate for yield and conversion of fatty acid methyl esters using face centered central composite design of Design Expert 6.0.8 can ensure purity of product, conserve energy and reduce waste generation providing a significant frontier in biodiesel pricing.
Sujata Mandal, Sreekar B. Marpu, Roxana Hughes, Mohammad A. Omary, Sheldon Q. Shi
Green and Sustainable Chemistry, Volume 11, pp 28-38; doi:10.4236/gsc.2021.111004

Abstract:
A procedure for the green synthesis of silver nanoparticles (AgNPs) using Cannabis sativa (hemp plant) as a stabilizing media was developed and antibacterial activity was tested. Within 30 minutes of heating the mixture of silver nitrate and hemp extract, the formation of silver nanoparticles took place under the complete absence of a chemical reducing or an additional stabilizing agent. The so-formed AgNPs were characterized using different optical spectroscopy and electron microscopy techniques. The initial formation of AgNPs was established from UV-Vis data based on surface plasmon resonance (SPR) of AgNPs at ~417 nm. The exact size, shape, and elemental composition of AgNPs were established from ESEM images and EDS data. The antibacterial activity of these nanoparticles was studied on Gram-positive Staphylococcus aureus, and Gram-negative Escherichia coli following Disk diffusion and Minimum Inhibitory Concentration (MIC) tests. Results showed that the biosynthesis of silver nanoparticles using hemp extract could be a simple,inexpensive, and biocompatible method.
Katenta Joseph, Nakiguli Caroline, Mukasa Paul, Ntambi Emmanuel, Joseph Katenta, Caroline Nakiguli, Paul Mukasa, Emmanuel Ntambi
Green and Sustainable Chemistry, Volume 10, pp 91-107; doi:10.4236/gsc.2020.103007

Abstract:
The potential of the Senegal date palm (Phoenix reclinata) seed bio-char to remove chromium (VI) ions from aqueous solutions by adsorption was investigated. Adsorption experiments were performed on the tannery effluent and standard aqueous solutions of chromium (VI) for varying adsorbent doses, contact times, pH, temperatures, and interfering anionic ions by batch mode. Phoenix reclinata seeds (PRS) bio-char was used in the investigation and the residual chromium (VI) was determined using the atomic absorption spectrophotometer (AAS). Results showed that the bio-char removed up to 86% of chromium (VI) ions in the effluent at pH 2. The highest percentage adsorption registered was 97% in an aqueous solution of chromium (VI) at pH 1 and this dropped to less than 10% at pH greater than 2. A general increase in adsorption with the increase in temperature was observed but reduced when the temperature was raised beyond 60°C. The presence of interfering anions caused a reduction in the adsorption of chromium (VI) ions. The adsorption process fitted both Langmuir and Freundlich adsorption models and the maximum adsorption capacity, Qo, was 0.6593 mg/g. Thus, PRS bio-char can therefore be used by industries and institutions like secondary schools to treat effluents that contain chromium (VI).
Kshama Parajuli, Aravind Kumar Sah, Hari Paudyal
Green and Sustainable Chemistry, Volume 10, pp 117-132; doi:10.4236/gsc.2020.104009

Abstract:
Because of various disadvantages of chemical synthesis processes, these days people are attracting towards green synthesis processes as it is devoid of toxic by-products, cost-effective and eco-friendly. In this study, a simple green synthesis method is applied for the synthesis of magnetite (Fe3O4) nanoparticles (MNPs) by co-precipitation of FeCl3·6H2O and FeSO4·7H2O in the molar ratio of 2:1 using Azadirachta indica leaves extract under nitrogen environment. FTIR, XRD, SEM etc. were used to characterize the synthesized MNPs. Batch adsorption experiments were carried out to determine adsorption equilibrium of As(V) as a function of pH, adsorbent dose, contact time and different initial concentrations. Kinetics results were best described by pseudo-second order model with rate constant value 0.0052 g/(mg·min). The equilibrium adsorption isotherm was best fitted with Langmuir adsorption isotherm model. The maximum adsorption capacity was found to be 62.89 mg/g at pH 2. MNPs showed a high affinity for As(V) and avoids filtration for solid-liquid separation, thus it would be employed as a promising material for the removal of As(V) from water.
A. Matin Mohammad, Bhattacharjee Samiran, Aftab Ali Shaikh, Debnath Tapas, Abdul Aziz Mohammed, Mohammad A. Matin, Samiran Bhattacharjee, Tapas Debnath, Mohammed Abdul Aziz
Green and Sustainable Chemistry, Volume 10, pp 39-55; doi:10.4236/gsc.2020.102004

Abstract:
As a substitute for lithium ion batteries, Na chemistry for ion battery systems is promising materials for energy storage applications for the next generation. Herein, the structures, IR and UV-visible spectra of 2-aminoterephthalic acid (H2ATA), disodium 2-aminoterephthalate (Na2ATA), trisodium 2-aminotere-phthalate (Na3ATA) and tetrasodium 2-aminoterephthalate (Na4ATA) have been studied using density functional theory (DFT/B3LYP/6-311++G(d,p)). The theoretical geometric parameters and FTIR results showed very good agreement with the experimental results. Different conformers of Na2ATA, Na3ATA and Na4ATA showed that the binding energy per sodium in Na2ATA, Na3ATA and Na4ATA is -694.94, -543.44 and -407.46 kJ/mol, respectively. The Na3ATA and Na4ATA salts are higher in energy (151.46 and 287.48 kJ/mol, respectively) than Na2ATA, indicating the higher stability of the Na2ATA complex. The calculated binding energy, enthalpy and Gibbs free energy of Na2ATA, Na3ATA and Na4ATA revealed that the compounds are thermodynamically stable. Natural bond orbital (NBO) analysis of Na2ATA, Na3ATA and Na4ATA indicated that the major interaction occurs between the lone pair electrons of the oxygen atom and anti-bonding orbitals of carbon atoms of the two carboxylate ions. UV-visible spectrum of the free H2ATA and its sodium salts Na2ATA, Na3ATA and Na4ATA were performed using the time-dependent density functional theory (TD-DFT) method at the level of B3LYP/6-311++G(d,p). The frontier molecular orbital energetic parameters and global reactivity descriptors revealed that the Na4ATA and Na3ATA complexes exhibited a higher band gap (ΔEgap) and electronegativity (χeV) than Na2ATA.
Baktygul Abylaeva, Tilebaldy Abdulazizov, Zamira Sandybaeva, Zhypargul Abdullaeva, Ernis Bepiev, Zakhro Akhmedova
Green and Sustainable Chemistry, Volume 10, pp 109-116; doi:10.4236/gsc.2020.104008

Abstract:
This article is investigating the preparation of essential oil from the ether-containing plants of Juniper (Juniperus) and spruce (Picea) leaves by using the simple water distillation equipment. This water distillation method forms an essential oil with water vapor from plants of Juniper (Juniperus) and spruce (Picea) leaves based on Dalton’s law of partial pressure, applicable for plants containing a large amount of ether oil where distillation temperature is not affecting product quality. Obtained essential oils are widely used in medicine, perfumery, cosmetics, and food industry. In addition, these essential oils possess different activities including antimicrobial, antiviral, and anti-inflammatory, which have different effects such as adaptogenic, antidepressive, disinfection, and wound healing, diuretic, and antipyretic.
Shoko Suzuki, Hiroyuki Ito, Motoyoshi Noike, Shinji Ishizuka, Risehiro Nonaka, Kenji Funaki, Takeshi Kodama, Shujiro Sakaki, Tomomichi Nishino, Mina Ito, et al.
Green and Sustainable Chemistry, Volume 10, pp 1-17; doi:10.4236/gsc.2020.101001

Abstract:
Recently, the development of environmentally friendly syntheses of imine derivatives, which were attracting great attention for their reactivity and structure in various fields, progressed rapidly because the concept of green chemistry had deeply penetrated into society. In our previous work, we had reported new synthetic methods of imine derivatives using some active amines under solvent- and catalyst-free reaction conditions. This synthetic reaction proceeded smoothly and target compounds were obtained in excellent yields. In this system, when less reactive amines were used as substrates, the synthetic reaction was not finished in the short reaction time, and the corresponding compounds were given in moderate yields. In order to solve this point, we tried to improve the reaction conditions of this method. Through this improvement, it was found that pure target compounds could be obtained in excellent yields by using 1.1 equivalents of less reactive amines to aldehydes and extending the reaction time compared with our previous work. In this paper, we will introduce the detail of this study, and also report the result of the investigation of the reaction property by computational chemistry.
Mohammad A. Aldosari, Sawsan S. Darwish, Mahmoud A. Adam, Nagib A. Elmarzugi, Sayed M. Ahmed
Green and Sustainable Chemistry, Volume 10, pp 24-38; doi:10.4236/gsc.2020.101003

Abstract:
Massive limestones were used in construction of ancient Egyptian tombs, temples, obelisks and other sculptures. These stones are always exposed to physico-mechanical deterioration and destructive forces, leading to partial or total collapse. The task of reassembling this type of artifacts represents a big challenge for the conservators. Recently, the researchers are turning to new technologies to improve the properties of traditional adhesive materials and techniques used in re-assembly of broken massive stones. The epoxy resins are used extensively in stone conservation and re-assembly of broken stones because of their outstanding mechanical properties. The adding of nanoparticles to polymeric adhesives at low percentages may lead to substantial improvements of their mechanical performances in structural joints and massive objects. The aim of this study is to evaluate the effectiveness of montmorillonite clay, calcium carbonate, and silicon dioxide nanoparticles for enhancing the performances of epoxy adhesives used in re-assembly of archaeological massive limestones. Scanning electron microscopy (SEM) was employed in order to investigate the morphology of the prepared nanocomposites, and the distribution of nanoparticles inside the composites. Artificial aging, tensile, compressive, and elongation strength tests were used to evaluate the efficiency of epoxy-nanocomposites. The results showed that the epoxy-clay nanocomposites exhibited superior tensile, compressive, and elongation strength, in addition to improving the mechanical properties of stone joints.
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