Showing papers in "Industrial & Engineering Chemistry Research in 2011"
TL;DR: In this article, the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst were reported.
Abstract: Biodiesel is produced by the transesterification of oil triglycerides with methanol or ethanol, in the presence of a homogeneous or heterogeneous catalyst. This study aims to report the results of the transesterification of sunflower oil with methanol to produce biodiesel using CaO nanoparticles supported on NaX zeolite as catalyst. The effect of the CaO nanoparticles concentration on the NaX zeolite surface was studied in the range of 5−25 wt %. The transesterification reaction was carried out at reflux temperature of methanol, atmospheric pressure, a reaction time of 6 h, and with a 6:1 molar ratio of methanol to sunflower oil. Catalyst characterization was carried out by X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. It was concluded that methyl esters content is highly influenced by basicity and that the best catalyst was the one holding 16 wt % CaO nanoparticles. The produced biodiesel was 93.5% methyl esters and was found to fulfill the specifications of Europ...
1,687 citations
TL;DR: A review of nonsolvent induced phase separation membrane preparation and characterization for many commonly used membrane polymers is presented in this article, which includes membrane porosity and pore size distribution characterization, membrane physical and chemical properties characterization, and thermodynamic and kinetic evaluation of phase inversion process.
Abstract: The methods and mechanisms of nonsolvent induced phase separation have been studied for more than fifty years. Today, phase inversion membranes are widely used in numerous chemical industries, biotechnology, and environmental separation processes. The body of knowledge has grown exponentially in the past fifty years, which suggests the need for a critical review of the literature. Here we present a review of nonsolvent induced phase separation membrane preparation and characterization for many commonly used membrane polymers. The key factors in membrane preparation discussed include the solvent type, polymer type and concentration, nonsolvent system type and composition, additives to the polymer solution, and film casting conditions. A brief introduction to membrane characterization is also given, which includes membrane porosity and pore size distribution characterization, membrane physical and chemical properties characterization, and thermodynamic and kinetic evaluation of the phase inversion process. ...
1,063 citations
TL;DR: In this article, the role of rice husk and its ash in the removal of various pollutants from wastewater was reviewed and the adsorption mechanism, influencing factors, favorable conditions, etc., discussed.
Abstract: Rice husk, which is a relatively abundant and inexpensive material, is currently being investigated as an adsorbent for the removal of various pollutants from water and wastewaters. Various pollutants, such as dyes, phenols, organic compounds, pesticides, inorganic anions, and heavy metals can be removed very effectively with rice husk as an adsorbent. This article presents a brief review on the role of rice husk and rice husk ash in the removal of various pollutants from wastewater. Studies on the adsorption of various pollutants by rice husk materials are reviewed and the adsorption mechanism, influencing factors, favorable conditions, etc., discussed in this article. It is evident from the review that rice husk and its ash can be potentially utilized for the removal of various pollutants from water and wastewaters.
717 citations
TL;DR: In this article, the first application of common hydrocarbon processing catalysts to microalgae liquefaction in water was reported, in which six different heterogeneous catalysts were tested under inert (helium) and high-pressure reducing (hydrogen) conditions.
Abstract: We produced crude bio-oils from the microalga Nannochloropsis sp. via reactions in liquid water at 350 °C in the presence of six different heterogeneous catalysts (Pd/C, Pt/C, Ru/C, Ni/SiO2−Al2O3, CoMo/γ-Al2O3 (sulfided), and zeolite) under inert (helium) and high-pressure reducing (hydrogen) conditions. To our knowledge, this is the first application of common hydrocarbon processing catalysts to microalgae liquefaction in water. In the absence of added H2, all of the catalysts tested produced higher yields of crude bio-oil from the liquefaction of Nannochloropsis sp., but the elemental compositions and heating values of the crude oil (about 38 MJ/kg) were largely insensitive to the catalyst used. The gaseous products were mainly H2, CO2, and CH4, with lesser amounts of C2H4 and C2H6. The Ru and Ni catalysts produced the highest methane yields. Only the zeolite catalyst produced significant amounts of N2. Typical H/C and O/C atomic ratios for the crude bio-oil are 1.7 and 0.09, respectively. In the presen...
520 citations
TL;DR: A magnetically separable ZnFe2O4-graphene nanocomposite photocatalyst with different graphene content was prepared by a facile one-step hydrothermal method as discussed by the authors.
Abstract: A magnetically separable ZnFe2O4–graphene nanocomposite photocatalyst with different graphene content was prepared by a facile one-step hydrothermal method. The graphene sheets in this nanocomposite photocatalyst are exfoliated and decorated with ZnFe2O4 nanocrystals. It was found that in the presence of H2O2, the photodegradation rate of methylene blue (MB) was 88% after visible light irradiation for only 5 min and reached up to 99% after irradiation for 90 min. In comparison with pure ZnFe2O4 catalyst, ZnFe2O4–graphene serves a dual function as the catalyst for photoelectrochemical degradation of MB and the generator of a strong oxidant hydroxyl radical (·OH) via photoelectrochemical decomposition of H2O2 under visible light irradiation. ZnFe2O4 nanoparticles themselves have a magnetic property, which makes the ZnFe2O4–graphene composite magnetically separable in a suspension system, and therefore it does not require additional magnetic components as is the usual case.
509 citations
TL;DR: This review outlines the recent progress of using MOFs as a promising platform in biomedical applications due to their high drug loading capacity, biodegradability, and versatile functionality and demonstrates the potential of MOFs for continuous development and implementation inomedical applications.
Abstract: We have witnessed a rapid growth in the field of a new nanoporous material group, metal organic frameworks (MOFs), over the past decade. MOFs possess a wide array of potential applications in chemical engineering, chemistry, and materials science, including gas storage, gas separation, and catalysis. One of the areas MOFs started to appear recently is biomedical applications. The unique physical and chemical characteristics of MOFs make them promising candidates for drug storage and drug delivery, nitric oxide storage and delivery, imaging, and sensing. In this review, we outline the recent progress of using MOFs as a promising platform in biomedical applications due to their high drug loading capacity, biodegradability, and versatile functionality. We also demonstrate the potential of MOFs for continuous development and implementation in biomedical applications by discussing issues including stability, toxicology, and biocompatibility. Although significant progress has been made in utilizing MOFs for bio...
506 citations
TL;DR: In this article, the authors compared the capital, operating, and overall costs of a dedicated continuous manufacturing process to synthesize an active pharmaceutical ingredient (API) and formulate it into tablets for a production scale of 2000 t of tablets per year.
Abstract: The capital, operating, and overall costs of a dedicated continuous manufacturing process to synthesize an active pharmaceutical ingredient (API) and formulate it into tablets are estimated for a production scale of 2000 t of tablets per year, with raw material cost, production yield, and API loading varied over broad ranges. Costs are compared to batch production in a dedicated facility. Synthesis begins with a key organic intermediate three synthetic steps before the final API; results are given for key intermediate (KI) costs of $100 to $3000/kg, with drug loadings in the tablet of 10 and 50 wt %. The novel continuous process described here is being developed by an interdisciplinary team of 20 researchers. Since yields are not yet well-known, and continuous processes typically have better yields than batch ones, the overall yields of the continuous processes with recycling were set equal to that of the batch process. Without recycling, yields are 10% lower, but less equipment is required. The continuou...
373 citations
TL;DR: A multiobjective, multiperiod, mixed-integer linear programming model is proposed that takes into account diverse conversion pathways and technologies, feedstock seasonality, geographical diversity, biomass degradation, infrastructure compatibility, demand distribution, and government incentives.
Abstract: This paper addresses the optimal design and planning of biomass-to-liquids (BTL) supply chains under economic and environmental criteria. The supply chain consists of multisite distributed–centralized processing networks for biomass conversion and liquid transportation fuel production. The economic objective is measured by the total annualized cost, and the measure of environmental performance is the life cycle greenhouse gas emissions. A multiobjective, multiperiod, mixed-integer linear programming model is proposed that takes into account diverse conversion pathways and technologies, feedstock seasonality, geographical diversity, biomass degradation, infrastructure compatibility, demand distribution, and government incentives. The model simultaneously predicts the optimal network design, facility location, technology selection, capital investment, production planning, inventory control, and logistics management decisions. The problem is formulated as a bicriterion optimization model and solved with the ...
340 citations
TL;DR: In this article, four methods, fast titration, salt addition, mass titration and ζ potentiometry, were employed to determine the point of zero charge (PZC) and isoelectric point (IEP) of NiO.
Abstract: Four methods, fast titration, salt addition, mass titration, and ζ potentiometry, were employed to determine the point of zero charge (PZC) and isoelectric point (IEP) of NiO. However, this work ma...
305 citations
TL;DR: This review summarizes efforts to develop cost-effective ecologically benign scale inhibitors, and the most promising green scale inhibitors are based on poly(aspartic acid), however, field operation data are very limited, and widespread use of poly( aspartic Acid) scale inhibitors awaits field operation use.
Abstract: Scale deposition is a difficulty encountered with water containing ions of sparingly soluble salts. A widely used technique for controlling scale deposition is by dosage of an antiscalant. Large quantities of polymeric scale inhibitors are used for scale control in cooling water systems, water desalination processes, and oil field operations. Like most conventional polymers, scale inhibitors are built for long existence and persist for many years after their disposal. Increasing environmental concern and discharge limitations have caused scale-inhibitor chemistry to move toward “green antiscalants” that readily biodegrade, have low mobility for minimum environmental impact, and are cost-effective. This review summarizes efforts to develop cost-effective ecologically benign scale inhibitors. Currently, the most promising green scale inhibitors are based on poly(aspartic acid). However, field operation data are very limited, and widespread use of poly(aspartic acid) scale inhibitors awaits field operation e...
296 citations
TL;DR: In this article, expandable graphite (EG), graphene, graphite oxide (GO), and organic phosphate functionalized graphite oxides (FGO) were prepared and incorporated into epoxy resin (EP) matrix via in situ polymerization to prepare EP based composites.
Abstract: Starting from expandable graphite (EG), graphene, graphite oxide (GO), and organic phosphate functionalized graphite oxides (FGO) were prepared and incorporated into epoxy resin (EP) matrix via in situ polymerization to prepare EP based composites. The structure of the composites was characterized by transmission electron microscopy to show good dispersion without large aggregates. The thermal behavior investigated by thermogravimetric analysis indicated the EP/graphene composites show the highest onset temperature and maximum weight loss temperature compared with those added with GO and FGO. The flame retardant properties investigated by micro combustion calorimeter illustrate that both EP/graphene and EP/FGO composites perform better than EP/GO composites in flame retardant properties with a maximum reduction of 23.7% in peak-heat release rate when containing 5 wt % FGO and a maximum reduction of 43.9% at 5 wt % loading of graphene. This study represents a new approach to prepare functionalized GO with ...
TL;DR: A comprehensive survey of the currently available literature on NIPU can be found in this paper, where the syntheses of cyclo-carbonates oligomers, the reaction mechanism, and the preparation and application of different kinds of non-isocyanate polyurethane are discussed.
Abstract: Non-isocyanate polyurethane (NIPU) is a novel kind of polyurethane prepared by reaction of cyclo-carbonates and amines without use of toxic isocyanates. NIPU has attracted increasing attention because of its improvements in porosity, water absorption, and thermal and chemical resistance over conventional polyurethanes. Their potential technological applications include chemical-resistant coating, sealants, foam, etc. In this paper, on the basis of a comprehensive survey of the currently available literature on NIPU, we summarize recent progress in NIPU, and mainly discuss the syntheses of cyclo-carbonates oligomers, the reaction mechanism, and the preparation and application of different kinds of NIPU.
TL;DR: In this article, the effect of temperature on pyrolysis products (char, non-condensable gas, and bio-oil) was investigated, and the results showed that cellulose is the principal source of carbohydrates and phenols are the basis of the biooil from lignin, while the bio oil from xylan mainly consists of acids, ketones, aldehydes, esters, benzenes, alcohols, alkenes, phenols, alkanels, etc.
Abstract: Fast pyrolysis of cellulose, xylan, and lignin was experimentally conducted between 350 and 650 °C in a tube furnace, and the effect of temperature on pyrolysis products (char, noncondensable gas, and bio-oil) was investigated. The yields of char, noncondensable gas, and bio-oil were quantified using gas chromatography and gas chromatography with mass spectrometry. The noncondensable gas mainly consists of CO, CO2, CH4, and H2. The bio-oil includes acids, ketones, aldehydes, esters, benzenes, alcohols, alkenes, phenols, alkanels, carbohydrates, etc. The results show that cellulose is the principal source of carbohydrates and phenols are the basis of the bio-oil from lignin, while the bio-oil from xylan mainly consists of acids, ketones, aldehydes, and phenols. The char yields for the three components decrease with an increase in temperature, and the gas yields and bio-oil yields increase with an increase in temperature, reach a maximum at a certain temperature, and then decrease after that temperature. Th...
TL;DR: Amine-functionalized anion-tethered ionic liquids (ILs) were synthesized and investigated as potential absorbents for CO2 capture from postcombustion flue gas as discussed by the authors.
Abstract: Amine-functionalized anion-tethered ionic liquids (ILs), trihexyl(tetradecyl)phosphonium glycinate [P66614][Gly], alanate [P66614][Ala], sarcosinate [P66614][Sar], valinate [P66614][Val], leucinate [P66614][Leu], and isoleucinate [P66614][Ile], were synthesized and investigated as potential absorbents for CO2 capture from postcombustion flue gas. Their physical properties, including density, viscosity, glass transition temperature, and thermal decomposition temperature, were determined. The influence of changing the anion and, more specifically, the length of the alkyl chain is discussed. Furthermore, the CO2 absorption isotherms of [P66614][Gly], [P66614][Ile], [P66614][Sar], and [P66614][Ala] were measured using a volumetric method, and the results were modeled with two different Langmuir-type absorption models. All four ILs reached greater than 0.5 mol of CO2 per mole of IL at CO2 pressures of less than 1 bar. This indicates the predominance of the 1:1 mechanism, where the CO2 reacts with one IL to for...
TL;DR: In this article, several SBA-15 silica materials with different pore structures were synthesized and functionalized with poly(ethyleneimine) (PEI), and the as-prepared materials were characterized by XRD, SEM, TG, FT-IR, and N2 physisorption techniques followed by testing for CO2 capture using a N2 stream containing 15.1 v/v% CO2 in the temperature range of 30−75 °C.
Abstract: Several SBA-15 silica materials with different pore structures were synthesized and functionalized with poly(ethyleneimine) (PEI). The as-prepared materials were characterized by XRD, SEM, TG, FT-IR, and N2 physisorption techniques followed by testing for CO2 capture using a N2 stream containing 15.1 v/v% CO2 in the temperature range of 30−75 °C. The results showed that the CO2 adsorption capacity linearly increased with the total pore volume of the SBA-15 phases in the tested temperature range (R2 > 0.94). Temperature also showed a strong influence on CO2 adsorption capacity. SBA-15 material with the largest pore volume (1.14 cm3 g−1) exhibited the largest CO2 adsorption capacity (105.2 mg g−1 adsorbent) with 15.1 v/v% CO2 in N2 at 75 °C and atmospheric pressure. Pore size was found not to be the main factor influencing the CO2 adsorption capacity of these PEI-modified SBA-15 materials. Adsorption−desorption cycles (12) revealed that the adsorbents with PEI loaded inside the pore channels were found to b...
TL;DR: In this paper, a laboratory study of foams intended to improve immiscible gas flooding in oil production is presented, which is relevant for both continuous and water alternating gas injection.
Abstract: This paper reports a laboratory study of foams intended to improve immiscible gas flooding in oil production. The study is relevant for both continuous and water alternating gas (WAG) injection sch...
TL;DR: Different uncertainty sets, including those studied in literature and new ones, are studied and their geometric relationship is discussed and robust counterpart optimization formulations induced by those different uncertainty sets are derived.
Abstract: Robust counterpart optimization techniques for linear optimization and mixed integer linear optimization problems are studied in this paper. Different uncertainty sets, including those studied in literature (i.e., interval set; combined interval and ellipsoidal set; combined interval and polyhedral set) and new ones (i.e., adjustable box; pure ellipsoidal; pure polyhedral; combined interval, ellipsoidal, and polyhedral set) are studied in this work and their geometric relationship is discussed. For uncertainty in the left hand side, right hand side, and objective function of the optimization problems, robust counterpart optimization formulations induced by those different uncertainty sets are derived. Numerical studies are performed to compare the solutions of the robust counterpart optimization models and applications in refinery production planning and batch process scheduling problem are presented.
TL;DR: In this article, a series of poly(ethylene glycol)diacid-coated (PEG−(COOH)2)-coated magnetic nanoparticles with different size distributions have been synthesized by means of the thermal decomposition method.
Abstract: Forward osmosis (FO) is an emerging technology for desalination and water reuse. However, a big challenge is finding suitable draw solutes. In this work, we have synthesized magnetic nanoparticles (MNPs), investigated their potential as draw solutes in FO systems, and explored their recovery and reusability. A series of poly(ethylene glycol)diacid-coated (PEG−(COOH)2-coated) MNPs with different size distributions have been synthesized by means of the thermal decomposition method. The physical properties and chemical compositions of the resultant MNPs are fully characterized. Transmission electron microscopy (TEM) analyses show the characteristics of spherical morphology with narrow size distribution, and a mean size from 4.2 to 17.5 nm depending on the ratio of the two starting materials of PEG−(COOH)2 to ferric triacetylacetonate (Fe(acac)3). Vibrating sample magnetometer analyses confirm the magnetic behavior of the PEG−(COOH)2 MNPs. The PEG−(COOH)2 layer on the MNPs ascertained from Fourier transform i...
TL;DR: In this paper, the authors studied the performance of three types of bifunctional catalysts: Pt/H-Y, Pt/ZSM-5, and sulfided NiMo/γ-Al2O3.
Abstract: As an alternative way to produce diesel hydrocarbons, the hydrocracking of rapeseed oil was studied on three different types of bifunctional catalysts: Pt/H-Y, Pt/H-ZSM-5, and sulfided NiMo/γ-Al2O3. Experiments were carried out in a batch reactor over a temperature range of 300−400 °C and initial hydrogen pressures from 5 to 11 MPa. The reaction time was limited to 3 h to prevent a high degree of cracking. The Pt-zeolite catalysts had a strong catalytic activity for both cracking and hydrogenation reactions, and therefore a higher severity was required to reach a relatively high oil conversion into liquid hydrocarbons. With dependence on the activity of the acid sites of the catalysts, the results show a trade-off between the yield of green diesel and the degree of isomerization, which had a direct effect on the cold properties of the diesel. Among the three catalysts, hydrocracking on Ni-Mo/γ-Al2O3 gave the highest yield of liquid hydrocarbons in the boiling range of the diesel fraction, i.e., green dies...
TL;DR: In this paper, the UL-94 V0 materials were obtained with a formulation of 18 wt % IFR and 2 Wt % graphene, which significantly enhanced the melt viscosity and restrained the melt dripping.
Abstract: Intumescent flame retardant poly(butylene succinate) (IFRPBS) composites with enhanced fire resistance were prepared using graphene as synergist. The morphology of fracture surfaces of the composites was investigated by scanning electron microscopy (SEM). The limiting oxygen index (LOI) values increased from 23.0 for the pure PBS to 31.0 for IFRPBS with 20 wt % IFR loading. The addition of graphene further improved the LOI values of the composites and exhibited excellent antidripping properties. The UL-94 V0 materials were obtained with a formulation of 18 wt % IFR and 2 wt % graphene. MFI measurement indicated that the presence of graphene significantly enhanced the melt viscosity and restrained the melt dripping. The thermal degradation and gas products of IFRPBS/graphene systems were monitored by thermogravimetric analysis (TGA), real time Fourier transform infrared spectrometry (RTFTIR), and thermogravimetric analysis-Fourier transform infrared spectrometry (TG-FTIR). X-ray photoelectron spectroscopy ...
TL;DR: In this paper, the authors investigated the possible use of ILs as solvents for two separation problems frequently encountered in petroleum industry: aromatic sulfur compound + aliphatic hydrocarb.
Abstract: The aim of this study is to investigate the possible use of ILs as solvents for two separation problems frequently encountered in petroleum industry: {aromatic sulfur compound + aliphatic hydrocarb...
TL;DR: In this paper, a systematic approach for the optimal production planning and facility placement of a biorefinery is presented, where a structural representation is developed to include sources of biomass.
Abstract: This paper presents a systematic approach for the optimal production planning and facility placement of a biorefinery. A structural representation is first developed to include sources of biomass f...
TL;DR: In this paper, a new phenanthroline derivative, 2-mesityl-1H-imidazo[4,5-f][1,10]phenanthroine (MEIP), was synthesized and characterized by elemental analysis, FT-IR, 1HNMR, and 13CNMR spectra.
Abstract: A new phenanthroline derivative, 2-mesityl-1H-imidazo[4,5-f][1,10]phenanthroline (MEIP), was synthesized and characterized by elemental analysis, FT-IR, 1HNMR, and 13CNMR spectra. MEIP was evaluated as corrosion inhibitor for carbon steel in 0.5 M H2SO4 solution using gravimetric and UV−visible spectrophotometric methods at 303−333 K. Results obtained show that MEIP is a good inhibitor for mild steel in H2SO4 solution. The inhibition efficiency was found to increase with increase in MEIP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. Activation parameters and Gibbs free energy for the adsorption process using Statistical Physics were calculated and discussed. The UV−visible absorption spectra of the solution containing the inhibitor after the immersion of mild steel specimen indicate the formation of a MEIP-Fe complex. The calculations of global reactivity indices of MEIP such as the localization of frontier molecular orbitals, EHOMO, ELUMO, energy gap ...
TL;DR: A more efficient performance of several basic biochemical tolerance mechanisms provides an advantage to halophytes with respect to several environmental factors including heavy metals as mentioned in this paper, and therefore, they are more tolerant to heavy metals.
Abstract: A more efficient performance of several basic biochemical tolerance mechanisms provides an advantage to halophytes with respect to several environmental factors including heavy metals. Therefore, h...
TL;DR: In this paper, the non-isothermal cold crystallization and isothermal melt crystallization of both linear and long-chain-branched (LCB) polylactide (PLA) were investigated using a differential scan.
Abstract: In this study, the non-isothermal cold crystallization and isothermal melt crystallization of both linear and long-chain-branched (LCB) polylactide (PLA) were investigated using a differential scan...
TL;DR: In this paper, the quantum chemical conductor-like screening model for real solvents (COSMO-RS) method was evaluated as a theoretical framework to computationally investigate the application of room temperature ionic liquids (ILs) in absorptive technologies for capturing CO2 from power plant emissions to efficiently reduce both experimental efforts and time consumption.
Abstract: The quantum chemical Conductor-like Screening Model for Real Solvents (COSMO-RS) method was evaluated as a theoretical framework to computationally investigate the application of room temperature ionic liquids (ILs) in absorptive technologies for capturing CO2 from power plant emissions to efficiently reduce both experimental efforts and time consumption. First, different molecular models to simulate ILs and computational methods in geometry calculations were investigated to optimize the COSMO-RS capability to predict Henry’s Law coefficients using a demanding solubility sample test with 35 gaseous solute-IL systems and 20 CO2−IL systems. The simulation results were in good agreement with experimental data, indicating that using an ion-pair molecular model optimized in a gas-phase environment allows a finer COSMO-RS description of the IL structure influence on the CO2 and other solutes solubilities. Moreover, the COSMO-RS methodology was used for the first time to achieve a deeper insight into the behavio...
TL;DR: A review of surface chemistry concepts is presented in this paper, with the principal objective of identifying interfacial phenomena and surface chemistry interactions involved in gas hydrate formation and agglomeration in oil and gas pipelines.
Abstract: A review of surface chemistry concepts is presented, with the principal objective of identifying interfacial phenomena and surface chemistry interactions involved in gas hydrate formation and agglomeration in oil and gas pipelines. There are five types of interfaces where gas hydrates may form and aggregate: gas/liquid, liquid/liquid, gas/solid, liquid/solid, and solid/solid; where the gas is the hydrocarbon gas, liquid is either oil, water, or condensate, and solid is either gas hydrate or the pipe wall surface. A review of fundamental interfacial concepts can help create a better understanding of phenomena at these interfaces, and can help industry move from hydrate prevention to risk management. Two areas of surface chemistry have been selected to illustrate the concepts and mechanisms associated with these systems: surfactants and emulsions. Examples from the literature pertaining to gas hydrates are presented for each system.
TL;DR: In this article, a low-molecular-weight poly(allylamine) is prepared via free-radical polymerization, and the resulting polymer is impregnated into mesocellular silica foams at different amine loadings.
Abstract: Low-molecular-weight poly(allylamine) is prepared via free-radical polymerization, and the resulting polymer is impregnated into mesocellular silica foams at different amine loadings. The resulting poly(allylamine)–silica composites are demonstrated as effective adsorbents for the extraction of carbon dioxide from dilute (simulated flue gas) and ultradilute (simulated ambient air) gas streams. The composite adsorbents are shown to have comparable adsorption capacities to more-conventional poly(ethyleneimine)–silica adsorbents. Potential advantages of poly(allylamine)-derived adsorbents are discussed.
TL;DR: In this paper, Cacumen Platycladi extract was investigated for the biosynthesis of Ag nanoparticles (AgNPs) and the results showed that increasing the initial AgNO3 concentration at 30 or 60 °C increased the mean size and widened the size distribution of the AgNPs leading to red shift and broadening of the surface plasmon resonance absorption.
Abstract: Biosynthesis of Ag nanoparticles (AgNPs) by Cacumen Platycladi extract was investigated. The AgNPs were characterized by ultraviolet–visible absorption spectroscopy (UV–vis), transmission electron microscopy (TEM), selected-area electron diffraction (SAED), and X-ray diffraction (XRD). The results showed that increasing the initial AgNO3 concentration at 30 or 60 °C increased the mean size and widened the size distribution of the AgNPs leading to red shift and broadening of the Surface Plasmon Resonance absorption. The conversion of silver ions was determined by atomic absorption spectroscopy (AAS) and to discuss the bioreductive mechanism, the reducing sugar, flavonoid, saccharide, protein contents in the extract, and the antioxidant activity were measured using 3,5-dinitrosalicylic acid colorimetric; Coomassie brilliant blue; phenol-sulfuric acid; rutin-based spectrophotometry method; and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay methods. The results showed that the reducing sug...
TL;DR: In this article, the ability of minced banana peel to extract lead and copper ions from water and the parameters involved in this process were investigated, and the kinetics of copper and le...
Abstract: This article reports on an investigation into the ability of minced banana peel to extract lead and copper ions from water and the parameters involved in this process. The kinetics of copper and le...