Fourier Transform Infrared Resonance Research Articles

Effect of fly ash on properties and hydration of calcium sulphoaluminate cement-based materials with high water content

Abstract In this study, the effects of fly ash (FA) on the setting time, compressive strength, and hydration evolution of calcium sulphoaluminate (CSA) cement-based materials with high water content were investigated, targeting the design of a modified high-water material to delay excessively rapid setting time and enhance later-age strength. This was investigated using a combination of X-ray diffraction (XRD), Fourier transform infrared resonance (FTIR) spectroscopy, and Thermogravimetric Analysis (TGA). The results showed that the setting time of the high-water materials was delayed by increasing the FA content, with 15% being the optimal dosage for the setting time. A 5–10% content of FA is conducive to the development of later-age compressive strength and has a slight adverse effect on the early-age compressive strength of high-water materials. The microscopic test results show that FA mainly acts as a microaggregate in the early-age hydration process, whereas in the later-age hydration process, it promotes gypsum consumption and C2S hydration to form ettringite. The incorporation of FA effectively promotes ettringite formation in CSA cement-based materials with high water content. Therefore, the addition of FA can enhance the overall performance of high-water materials to a certain extent, and the long-term strength development of the material can satisfy engineering requirements.

Antibacterial Agent of Echinochloa esculenta-Mediated ZnO Nanoparticles on Urinary Infection-Causing Bacteria

Background: Echinochloa esculenta is the Indian Barnyard millet which is a grass type of species. This study focused on the evaluation of the antibacterial activity of Echinochloa esculenta-mediated zinc oxide nanoparticles (ZnONPs) against urinary tract infection (UTI) microbes, such as Escherichia coli (E. coli), Enterobacter aerogenes, Pseudomonas aeruginosa, Staphylococcus aureus, and Proteus vulgaris. Methods: The millet Echinochloa esculenta-mediated ZnONPs are synthesized using a green method. Synthesized ZnONPs are characterized by ultraviolet (UV), Fourier transform-infrared resonance spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX) to determine the functional groups, crystalline size, shape, and elemental composition of the synthesized NPs. Results: The UV and FTIR results of Echinochloa esculenta-mediated ZnONPs preliminarily confirmed the formation of ZnONPs. The XRD and SEM results also confirmed that the synthesized ZnONPs are well-crystalline in nature, and the average size was observed to be 23.38 nm with a spherical shape. Echinochloa esculenta-mediated ZnONPs contained 73.33% of zinc and 26.77% of oxygen, which was examined by EDX. Synthesized ZnONPs were tested against the five UTI pathogens, and they exhibited a greater zone of inhibitions than zinc acetate and plant extract. Especially against S. aureus, Echinochloa esculenta-mediated ZnONPs performed well with an inhibitory effect. Conclusions: Therefore, this study had the potential value of developing new eco-friendly, low-cost, and less toxic nanomaterials that can be used as a bio-control for diseases.

Synthesis, vibrational spectroscopic investigation, molecular docking, antibacterial and antimicrobial studies of a new anthraquinone derivative compound

A new anthraquinone derivative, 1-(2,5-dimethylpiperazin-1-yl)anthracene-9,10-dione, was synthesized and characterized by Fourier Transform-Infrared, Raman and nuclear magnetic resonance analysis. The optimized molecular geometry was obtained using Density Functional Theory, B3LYP method with a 6-311++G(d,p) basis set. The fundamental vibrational wavenumbers, IR and Raman intensities were calculated for the optimized structure and simulated spectra were compared with the experimental vibrational spectra. The calculated highest occupied molecular orbital and lowest occupied molecular orbital energies indicated the presence of charge transfer within the molecule. The antibacterial activities of the new amino anthraquinone derivate against gram-positive and gram-negative bacteria were determined. Molecular docking simulations were performed with the new anthraquinone derivative and DNA to reveal its anticancer property. It was found that the anthraquinone derivate was bound to DNA with a high binding affinity (ΔG = −31.8 kJ/mol) and interacted with the DG10, DC11 and DG16 residues via the intermolecular hydrogen bonds. Moreover, to investigate the antiviral activity of the compound and to expose its action mechanism as an antiCOVID-19 agent, in silico molecular docking studies were performed on the Angiotensin-Converting Enzyme-2, and SARS-CoV-2 targets (holo and apo forms of main proteases Mpro and spike glycoprotein).

DOPA-melanin, component and tolerance factor to heat and UV-B radiation in the conidia of two species of Cordyceps

ABSTRACT Melanins are heterogeneous pigments present in all biological kingdoms with many biological roles, mainly related to coping with environmental stress. In some species of fungi, melanin is involved in higher virulence against plants and animals; however, little is known about the presence and type of melanin found in entomopathogenic fungi (EF), used for biological pest control. In this work, we explore the presence of melanin in conidia from Cordyceps fumosorosea CHE-CNRCB 303 and Cordyceps javanica ARSEF 3302. Melanin from both species was purified and characterised by UV, Fourier transformed infrared resonance (FT-IR) and electron paramagnetic resonance (EPR). The DOPA-melanin pathway was established as the route used by the Cordyceps genus to synthesise the pigment, which presented the ability to reduce 2,2-diphenyl-1-picrylhydrazyl (DPPH), confirming its antioxidant capacity; furthermore, the melanised conidia of both Cordyceps species were more thermotolerant and resistant to UV-B radiation than non-melanised conidia. This is the first time that melanin has been characterised and its influence on conidia quality has been verified in two Cordyceps species, which are used extensively for pest control. This knowledge could improve both the persistence of conidia in the field and the effectivity in biological control.

Chemical and Mineralogical Composition Analysis of Different Nigerian Metakaolins

In this work, four different metakaolin samples (C01, A6060, B6075, and C12090) were investigated to determine their constituent elements and the relative quantities of the oxide contents associated with each of the elements. Kaolin samples were collected from different sites at Okpella, a village in the Edo state of Nigeria, West Africa. The metakaolin was produced by calcination at 750℃, which was followed by the dealumination process. The prepared samples were characterized by Field Emission Scanning Electron Microscope (FE-SEM), Energy Dispersive X-ray Spectroscopy (EDS), Fourier Transform Infrared Resonance (FTIR) spectroscopy, and X-ray diffraction (XRD) technique. Digital images were obtained and analyzed to determine the texture and porosity of the samples. FE-SEM images showed a slight difference in the morphology of the samples. Differing percentages of metal oxides were determined from the samples using EDS analysis. The major oxides present in all the samples were Silica (Silicon oxide) and Alumina (Aluminium dioxide). Aluminium was completely absent in C12090 but had a large percentage of silicon (36%).

Structure characteristics and immunomodulatory activities of a polysaccharide RGRP-1b from radix ginseng Rubra

The present study was undertaken to explore the structure characteristics, immune regulation, and anti-cancer abilities of polysaccharides in radix ginseng Rubra (RGR). For this purpose, RGR polysaccharides (RGRP) were purified through DEAE and S-300 chromatography. Monosaccharide composition, methylation, and GC–MS analyses, as well as field emission scanning electron microscope (FESEM), atomic force microscope (AFM), Fourier-transformed infrared resonance (FT-IR), and nuclear magnetic resonance (NMR) spectra, were used to establish the structure of RGRP-1b. Our results revealed that RGRP-1a and RGRP-1b possess different molecular weights (21.3 kDa and 10.2 kDa, respectively). RGRP-1a was found to be composed of glucose, while RGRP-1b was composed of glucose, galactose, and arabinose. The main chain structure of RGRP-1b was composed of 1,4-α-Glcp, with a 1,4,6-α-Glcp branch unit. Its side chains were branched at the O-4 position of 1,4,6-α-Glcp, namely 1)-β-Galp-(4 → 1)-α-Araf-(5 → α-Araf and 1)-β-Galp-(6 → α-Glcp. The changes in the nitric oxide (NO) levels and cytotoxicity revealed that macrophages probably get activated by RGRP-1b. The expressions of IL-6, IL-12, and TNF-α were found to be upregulated after treatment with RGRP-1b. RGRP-1b thus possesses the potential to arrest the growth of Huh7 through immunoregulation. Our cumulative findings indicate that RGRP-1b obtained from radix ginseng Rubra can function as a strong immune modulator.

Changes in the biochemical, hematological and histopathological parameters in STZ-Induced diabetic rats and the ameliorative effect of Kigelia africana fruit extract

BackgroundBiochemical, hematological and histological changes are major observable clinical and pathological factors associated with Diabetes mellitus. Derangement in the levels of these parameters increases the risk of the development of complications. In another hand, gastrointestinal intolerance due to the development of lactic acidosis on the gastrointestinal tract and the intestinal microbiome is the toxic side effect of various synthetic antidiabetic agents. The use of Kigelia africana fruit extract for the treatment of diabetes has been scientifically validated. This study therefore aimed at investigating changes in the biochemical, hematological and histological parameters as well as the determination of the functional groups present in the hexane fraction of the fruit. MethodsThe fruits were extracted with ethanol and partitioned with n-hexane to obtain the hexane fraction. Diabetic rats induced with streptozotocin (STZ) were divided into 5 groups of 5 animals each and treated with 100, 200 and 400 mg/kg body weight (BW) hexane fraction alongside reference standard; glibenclamide. Fasting blood glucose levels and their body weights were monitored weekly. Animals were sacrificed at the end of 28-day treatment. Blood, liver, and kidney were collected for biochemical, hematological and histopathological analyses. Fourier transform infrared resonance (FTIR) spectroscopic analysis was carried out on the hexane fraction for functional group determination. ResultsThe hexane fraction of K. africana fruit extract decreased fasting blood glucose (FBG) levels significantly with ameliorative effects on the hematological parameters such as packed cell volume (PCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red blood cells (RBC) etc. There were significant regenerative differences in the biochemical activities as well as the renal cortex and midzone sections of the rat's kidney and liver when compared with untreated diabetic rats. The presence of polyphenolic functional groups via FTIR analysis suggested high antioxidant activities of the fruit extract. ConclusionThe use of Kigelia africana fruit extracts protects against biochemical, hematological and histological changes that are injurious to diabetic patients. Therefore, Kigelia africana fruit is a good hepatic- and nephroprotective agent and has a hemato-protective ability.

A PRELIMINARY STUDY ON DETECTION OF CADMIUM (II) ION USING BENZOYL PHENYLTHIOUREA

Two benzoyl phenylthiourea derivatives namely: 1-benzoyl-3-(4-bromophenyl)-2- thiourea (M) and 1-(4-chlorobenzoyl)-3-(4-methylphenyl)-2-thiourea (MI) were successfully synthesized and characterized by using Carbon, Hydrogen and Nitrogen (CHN) micro elemental analysis, Fourier Transform Infra-Red (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy methods. Elemental analysis for M (C14H11N2SOBr) and MI (C15H13N2SOCl) were compatible with the expected theoretical calculation. The FTIR spectrum obtained for M and MI compounds show the presence of four important functional groups; ʋ(N-H), ʋ(C=O), ʋ(C-N) and ʋ(C=S) that appeared at 3380-3367 cm-1, 1666-1681 cm-1, 1342-1268 cm-1 and 1146-1152 cm-1, respectively. The NMR spectrum data for MI shows the chemical shift at 6.63-7.85 ppm for Ar-H group, 2.26-2.40 ppm for methyl group, 7.44 ppm for N1H and 3.09 ppm for N2H. For the application, M and MI were used as probes in detecting Cd2+ in methanol solution. UV-Visible spectrophotometer was used to analyze the absorbance values of the compound before and after Cd2+ was added. It is found that compound M displayed the behavior of ‘turn off’ sensors while compound MI possessed the behavior of ‘turn on’ when detecting 0.5×10-5 M and 1×10- 5 M of Cd2+ ion. The behavior of ‘turn on’ and ‘turn off’ is due to the increasing or decreasing of absorbance when Cd2+ was added to the compounds.

Antimicrobial and Phytochemical Screening of the Methanolic Stem Bark Extract of Ficus abutilifolia (Miq.) and Some Spectral Studies on One Isolated Component

The stem bark extract of Ficus abutilifolia (Miq.) , an ethnomedicinally important member of the Moraceae family, was analysed with the three-fold aim of identifying its phytochemical components, determining its antimicrobial effects and efficacy, and isolating a component to be structurally elucidated by Fourier-Transform Infrared (FTIR) and Proton Nuclear Magnetic Resonance ( 1 HNMR) studies. Extraction was carried out by maceration method with methanol as the extraction solvent. Qualitative phytochemical analysis of the resulting methanolic extract gave positive results for carbohydrates, cardiac glycosides, saponins, steroid, triterpenes and alkaloids, while the antimicrobial screening revealed bioactivity against Staphylococcus aureus , Escherichia coli , and Pseudomonas aeruginosa . The extract was found to be bacteriostatic (growth-inhibitory) to S. aureus , E. coli and P. aeruginosa with respective Minimum Inhibitory Concentration (MIC) values of 25-, 50- and 25 mg/ml, but was bactericidal (lethal) only to S. aureus and P. aeruginosa with a common Minimum Bactericidal Concentration (MBC) value of 50 mg/ml. Column separation led to the successful isolation of a white crystalline substance with R f value of 0.25 using solvent ratio 1:4 of EtOAc:n-hexane solvent system. Studies on the FTIR and 1 HNMR spectra of the isolated compound revealed that it is a non-aromatic, non-conjugated six-membered lactone. Keywords: Ficus abutilifolia , antimicrobial screening, phytochemical, structural elucidation, isolation, stem bark, chromatography DOI: 10.7176/JNSR/10-6-05 Publication date: March 31 st 2020

Volatile Oil, Phytochemical, and Biological Activities Evaluation of Trachyspermum ammi Seeds by Chromatographic and Spectroscopic Methods

Trachyspermum ammi L. (bishop’s weed), belonging to Apiaceae family, is used as a condiment in curries, and in folk medicine for its antidiarrheal and anthelmintic properties and as a laxative. The current study was designed to extract and analyze the volatile oil of T. ammi by simultaneous-distillation extraction (SDE) and gas chromatography-mass spectrometry (GC-MS), and identify its major constituents by Fourier transform-infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Furthermore, the study evaluated the total phenolic and flavonoid contents, antioxidant, antibacterial, antifungal, and anticholinesterase activities by ultraviolet spectroscopy. Among the 81 prominent peaks observed in GC-MS, the major volatile flavor compounds were thymol (50.04%) > γ-terpinene (19.13%) > ρ-cymene (18.95%) > β-pinene (2.11%) > carvacrol (1.53%). Additionally, ethyl acetate, acetone, and methanol fractions exhibited comparatively high of phenolic and flavonoid contents. These fractions also potently inhibited the DPPH and ABTS free radicals. However, n-hexane, chloroform, and aqueous extracts were shown to provide significant antibacterial, antifungal, and anticholinesterase activities. Hence, T. ammi confirmed to be a rich source of volatiles and phenolics exhibiting significant antioxidant and anticholinesterase activities, and thus, may provide positive health impacts.

Polymerization of graphene oxide with polystyrene: Non-linear isotherms and kinetics studies of anionic dyes

This study describes the preparation of graphene oxide modified with polystyrene (GO-PS) and its application to Reactive Blue 19 (RB 19), Direct Red 81 (DR 81) and Acid Blue 92 (AB 92) adsorption from aqueous media. The adsorbents were characterized by Brunauer-Emmett-Teller (BET) technique, Fourier transform-infrared resonance (FTIR) spectroscopy, Energy-dispersive X-ray (EDX) spectroscopy and scanning electron microscopy (SEM) analysis. The average pore diameter of graphene oxide (GO) increased from 4.853 nm to 7.051 nm after polymerization. Adsorption capacities of GO-PS for dyes removal were evaluated through batch studies. For Reactive Blue 19, Direct Red 81 and Acid Blue 92 dyes (with an initial dye concentration of 20 mg/L), the adsorption capacities of final adsorbent were found to be 13.13, 19.84 and 15.44 mg/g, respectively. The adsorption equilibrium, isotherm and kinetic non-linear models were tested for the adsorption process and the experimental data were best fitted by the Freundlich isotherm with the high correlation coefficient (R2) of 0.999. The maximum adsorption capacities of dyes were achieved 43.280, 40.663 and 39.067 mg/g for Direct Red 81, Acid Blue 92 and Reactive Blue 19, respectively, by using the Langmuir isotherm model. Moreover, the adsorption kinetics of the dyes on GO-PS was well-described by Elovich (for Reactive Blue 19) and intraparticle diffusion models (for Direct Red 81 and Acid Blue 92). The results of this research revealed that GO-PS is a promising adsorbent for removal of anionic dyes in aqueous solution.

The deactivation of a ZnO doped ZrO2-SiO2 catalyst in the conversion of ethanol/acetaldehyde to 1,3-butadiene.

A deactivation study on the ethanol/acetaldehyde conversion to 1,3-butadiene over a ZnO promoted ZrO2–SiO2 catalyst prepared by a sol–gel method was performed. The samples were characterized by N2 adsorption–desorption isotherms, scanning electron microscopy (SEM), NH3 temperature programmed desorption (NH3-TPD), X-ray powder diffraction characterization (XRD), thermogravimetric analyses (TGA), Fourier transform infrared resonance (FT-IR), 13C magic-angle spinning nuclear magnetic resonance (13C NMR) and X-ray photoelectron spectroscopy (XPS). The pore structure characteristics and surface acidity of Zn0.5–Zr–Si catalysts were largely decreased with time-on-stream and no crystal structure was formed in the used catalyst, indicating that the deactivation was caused by carbon deposition. Two main types of carbon deposition were formed, namely low-temperature carbon deposition with the oxidation temperature of around 400 °C and high-temperature carbon deposition with the oxidation temperature of 526 °C. The carbon species were mainly composed of graphitized carbon, amorphous carbon, carbon in C–O bonds and carbonyls. The deactivated catalyst could be regenerated by a simple oxidation process in air. Adding a certain amount of water into the feed had a positive effect on reducing the carbon deposition.

Effect of polyhedral oligomeric silsesquioxane nanoreinforcement on the properties of epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) nanocomposites

This article reports the synthesis and characterization of several types of organic–inorganic nanocomposites based on epoxy resin/monoglycidylether-terminated poly(dimethylsiloxane) reinforced with 2, 5, or 10 wt% polyhedral oligomeric silsesquioxanes (POSS) bearing one glycidyl (1GE-POSS) or eight glycidyl(8GE-POSS) groups. The morphological features of the studied samples were established through atomic force microscopy, contact angle measurements, X-ray photoelectron spectroscopy, and scanning electron microscopy/energy-dispersive X-ray spectroscopy, and it was demonstrated that 8GE-POSS is well dispersed within the polymer matrix, while 1GE-POSS exhibits a high tendency to form aggregates. Differential scanning calorimetry (DSC) and Fourier transform infrared resonance (FTIR) measurements are used to follow the curing behavior and to study the polymerization kinetics of epoxy groups. As evidenced by DSC and FTIR results, the inclusion of 8GE-POSS within the polymer matrix leads to a lower epoxy polymerization rate of the resulted nanocomposites than those reinforced with 1GE-POSS. The dynamic mechanical analysis results revealed that the thermomechanical properties are gradually improved with increasing of 8GE-POSS content due to the higher cross-linking density.

Surface oxygen micropatterns on glow discharge polymer targets by photo irradiation

Recent simulations predict surface oxygen may be a significant source of disruptive perturbations in the implosion process of glow-discharge polymers (GDP) ablators at the National Ignition Facility. GDP material held in ambient atmospheric conditions showed an increase in mass when stored in light transparent containers, which suggests that photo exposure is a driving force for oxygen absorption. To investigate if surface oxygen is a contributing factor of disruptive perturbations during implosion, a method to imprint a periodic micropattern of oxygen on the surface of GDP was developed and used to fabricate a flat sample for empirical testing. Photo exposure using collimated blue light was used to generate micropatterns of surface oxygen on the GDP material. The periodic oxygen micropattern was confirmed by secondary ion mass spectrometry (SIMS) and energy dispersive spectroscopy. A SIMS depth profile showed the atomic percent of oxygen ranged from 8 at. % near the surface to 1 at. % at a depth of 2 μm in a sample exposed for 4 min. The molecular interactions formed between the GDP and oxygen molecules were characterized using Fourier transform infrared resonance (FTIR), which showed the formation of hydroxyl (O–H) and carbonyl (C=O) bonds. The FTIR enabled the oxygen mass uptake as a function of photo exposure time to be quantified (resolved to typically 0.05 at. % oxygen). This experimental protocol was then applied to produce a GDP flat part with a periodic 75 μm wavelength micropattern of photo exposed (oxygen rich) and masked (oxygen deficient) regions. The micropatterned GDP ablators developed in this work are being used to assess the effect of surface oxygen on disruptive perturbations during the inertial confinement fusion implosion process.

Synthesis and Characterization of some Diazotised Resins from Renewable Resource

Cashew phenol, popularly known as Cardanol, is reddish brown liquid prepared from cashew nut shell liquid (CNSL). Cardanol is found to be an important renewable resource and possess unique phenolic group having a 15-carbon aliphatic side chain at meta position with varying degrees of unsaturation. It is immiscible in water but miscible in most of the organic solvents. It's excellent solubility in number of common organic solvents makes it an ideal choice for a large number of surface-coating applications including paints and primers, varnishes and lacquers, etc. The synthesis of resins involves diazotization of p-nitroaniline followed by coupling the diazotized product with cardanol in order to get diazotised p-nitroaniline cardanol dye. The condensation reaction between the resulting dye and furfural in presence of H2SO4 furnished the homopolymer resin. The homopolymer resin is further condensed with urea and thiourea in order to get the desired copolymer resin. All the steps are preceded with good yields and required simple purifications. The products from each step are characterized using Ultra violet-Visible spectroscopy, Fourier Transform-Infrared spectroscopy and 1H-Nuclear Magnetic Resonance spectroscopy. The expected product formation is confirmed by careful analysis of the spectral results and also compared with the previous literature reports. Further, the synthesized product will be subjected to Inter-penetrating polymer network sheet formation and checked its potential applications in the field of coating materials.

Studies on removal of Pb(II) and Cr(III) using graphene oxide based inverse spinel nickel ferrite nano-composite as sorbent

Synthesis of a hybrid graphene oxide based inverse spinel nickel ferrite (GONF) nano-composite material and subsequent utilization in heavy metal removal from aqueous solution is described in the present study. The synthesized GONF was characterized using X-ray diffraction (XRD), Fourier transform-infrared resonance (FT-IR), and X-ray photoelectron (XPS) spectroscopies. The morphology, the surface area and pore volume of GONF were evaluated by scanning electron microscopy (SEM) and BET analysis, respectively. GONF was successfully used for the removal of Pb(II) and Cr(III) by batch adsorption techniques. Batch kinetics studies revealed that the sorption of Pb(II) and Cr(III) onto GONF was well described by a pseudo-second-order equation. The sorption equilibrium data of Pb(II) and Cr(III) was well tuned to the Langmuir isotherm model than the Freundlich and Temkin isotherm models. Hence, the sorption of Pb(II) and Cr(III) onto GONF occurred through monolayer chemisorptions on the homogeneous surface of GONF. The pH sorption results suggest that the sorption occurs through a complexed mechanism. The sorption of metal ions increased with increasing temperature, which is evident for an endothermic chemisorption by inner-sphere surface complexation. The overall obtained results demonstrated the GONF as an effective sorbent for Pb(II) and Cr(III) removal from wastewater.

Rapid octreotide separation from synthetic peptide crude mixtures by chromatography on poly(styrene–co-divinylbenzene)-based reversed phases

Octreotide, a disulfide-cyclized eight amino acids long analogue of somatostatin, has been used to treat the symptoms associated with metastatic carcinoid tumors (flushing and diarrhea), and vasoactive intestinal peptide secreting adenomas (watery diarrhea). As composed by D-amino acids, C-terminal alcohol, and disulfide bond, octreotide can be only prepared using chemistry synthesis method, which increases difficulty of the traditional reversed-phase separation. In this paper, we report a very fast separation of octreotide from synthetic peptide crude mixtures on a poly(styrene co-divinylbenzene) (PSt)-based reversed phases prepared by a quick membrane emulsification process. In general, fourier-transformed infrared resonance (FT-IR) spectroscopy, reversed-phase high performance liquid chromatography (HPLC) combined with electrospray ionisation mass spectrometry (ESI-MS), and nuclear magnetic resonance (NMR) spectroscopy are routinely used for analyses of resultant peptides. Under the optimized conditions, the octreotide is purified from 42.89% to 99.99%. Consequently, the poly(styrene co-divinylbenzene)-based phase can provide more flexibility to improve separation efficiency for the octreotide from the synthetic peptide crude mixtures. (C) 2015 Elsevier B.V. All rights reserved.

Biochar-surface oxygenation with hydrogen peroxide

Biochar was produced from pinewood biomass by pyrolysis at a highest treatment temperature (HTT) of 400 °C. This biochar was then treated with varying concentrations of H2O2 solution (1, 3, 10, 20, 30% w/w) for a partial oxygenation study. The biochar samples, both treated and untreated, were then tested with a cation exchange capacity (CEC) assay, Fourier Transformed Infrared Resonance (FT-IR), elemental analysis, field water-retention capacity assay, pH assay, and analyzed for their capacity to remove methylene blue from solution. The results demonstrated that higher H2O2 concentration treatments led to higher CEC due to the addition of acidic oxygen functional groups on the surface of the biochar, which also corresponds to the resultant lowering of the pH of the biochar with respect to the H2O2 treatment. Furthermore, it was shown that the biochar methylene blue adsorption decreased with higher H2O2 concentration treatments. This is believed to be due to the addition of oxygen groups onto the aromatic ring structure of the biochar which in turn weakens the overall dispersive forces of π–π interactions that are mainly responsible for the adsorption of the dye onto the surface of the biochar. Elemental analysis revealed that there was no general augmentation of the elemental composition of the biochar samples through the treatment with H2O2, which suggests that the bulk property of biochar remains unchanged through the treatment.

Simonkolleite-graphene foam composites and their superior electrochemical performance

Simonkolleite-graphene foam (SimonK/GF) composite has been synthesized by a facile solvothermal and environmentally friendly technique with excellent electrochemical properties. The obtained product was initially analyzed by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), Fourier transform infrared resonance (FTIR) spectroscopy and cyclic voltammetry (CV) techniques. The microscopy results reveal hexagonal sheets interlaced with each other and adjacent graphene sheets. The existence of graphene foam in the simonK/GF composite is further confirmed from the structural and the optical characteristics obtained from XRD and FTIR respectively. The BET results obtained indicate an improvement in the surface area due to the addition of graphene foam to a value of 39.58m2g−1. The N2 adsorption/desorption also shows the presence of active mesopores required for charge transport. As a promising electrode material for supercapacitors, the composite shows a high specific capacitance value of 1094F/g at 1A/g with a coulombic efficiency of 100% after 1000 cycles. These results show a potential for adoption of this composite in energy storage applications.

Stabilization Mechanism and Effect Evaluation of Stabilized Silt with Lignin Based on Laboratory Data

The potential of a lignin-based by-product to stabilize silt was evaluated. The physical and mechanical properties of silt in its natural state, as well as when treated with varying proportions of lignin, were analyzed. The parameters tested include the particle size distribution, Atterberg limits, compaction characteristics, unconfined compressed strength, pH value, and electrical resistivity. To understand the stabilization mechanism of lignin-treated silt at a microscopic level, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and Fourier transform infrared resonance (FTIR) spectroscopy were also carried out on lignin and representative samples after 28 days of curing. The results indicate that the engineering properties of silt are improved by the addition of lignin. Particle size distribution is changed and plastic index is reduced from 8.8 to 7.7. After improvement, the maximum dry density increases and the optimum moisture content decreases, while the change of dry density with moisture content is enhanced. The treated silt has greater strength performance than the natural silt in terms of unconfined compressed strength and all of the samples have a pH value lower than 10. Curing time and moisture content have a significant impact on unconfined compressed strength but almost no effect on pH. Micro-chemical analysis reveals that the improvement of performance exhibited by lignin-treated silt may be mainly attributed to the cation exchange and the formation of more stable soil structure by lignin cementing. The stabilization mechanism of lignin-treated silt was proposed according to the results of chemical analysis. It is shown that lignin-based stabilizers have potential to improve the engineering properties of silt.