Field Emission Scanning Electron Microscopy Analysis Research Articles

Biocidal investigation, characterization and preparation of ferrous-cobalt codoped tin dioxide nanoparticles by microwave-assisted green technique using Psidium guajava leaf extract

Ferrous-cobalt (Fe-Co) co-doped tin oxide (SnO2) nanoparticles (NPs) were prepared using Psidium guajava leaf extract by microwave-assisted green synthesis. FeCo:SnO2 NPs was characterized using Fourier transform infrared spectroscopy (FTIR), Powder X-ray diffraction (PXRD), Field emission scanning electron microscopy (FESEM) and Energy dispersive X-ray spectroscopy (EDAX) techniques. PXRD patterns revealed the tetragonal structure of FeCo:SnO2 NPs, with an average crystalline size of 67 nm. The Sn-O stretching bands were detected in the FTIR spectra at 441 cm-1. FESEM analysis showed that FeCo:SnO2 NPs had a spherical structure and chemical composition of the elements such as Fe, Co, Sn and O identified by EDAX spectra. The oxygen vacancy of surface defects was explored using photoluminescence (PL) spectroscopy. The antibacterial activity of prepared NPs was evaluated against Staphylococcus aureus (S.aureus) and Klebsiella pneumonia (K. pneumonia) using well diffusion method. FeCo:SnO2 NPs exhibited better antibacterial activity than amoxicillin. The anticancer activity of FeCo:SnO2 NPs was explored against MCF-7 cell lines (human breast cancer). The biocidal results demonstrate that Psidium guajava leaf extract-derived FeCo:SnO2 NPs showed significant inhibition against tested bacterial strains and enhanced potency against MCF-7 cancer cell lines.

DEEP CRYOGENIC TREATED HIGH CARBON STEEL BLADES: TRIBOLOGICAL, MORPHOLOGICAL, AND ECONOMIC ANALYSIS

Straw combines are intended to process the remaining harvested straw. When cut at high temperatures and in abrasive conditions, the cutting blade of straw combines undergoes substantial surface deterioration. This deterioration shortens the blade’s lifespan and increases the cutting cost of the machine. In recent decades, cryogenic treatments have played a significant role in enhancing material properties. In this paper, cryogenic treatment is utilized to boost the wear resistance of straw combine blades in the current investigation. The performance of cryogenic treatment was tested in the laboratory using the pin-on-disc wear tester with sample type, load, sliding velocity, and time serving as process factors and wear loss as the response parameter. The smoothness of the cryogenically-treated sample’s surface is certified through morphological examination. Specific wear rate and field emission scanning electron microscope (FE-SEM) indicated that cryogenic treatment enhances the grain structure and intermolecular interaction of the specimen, resulting in an increase in wear resistance. As opposed to the untreated specimen, the wear on the treated surface is uniform over the entire surface, as demonstrated by FE-SEM analysis. The grain structure and intermolecular bonding of the specimen were improved as a result of the cryogenic treatment. The cryogenic treatment increased the cost of the cutter bar and chopping cylinder blades by 9.38% and 13.61%, respectively, compared to untreated blades, but the increased cost was fully offset by the longer blade life.

Elliptically birefringent chemically tuned liquid crystalline nanocellulose composites for photonic applications

Cellulose nanocrystals (CNCs) based photonic materials are one of the promising materials in the recent trends. The liquid crystalline behavior of the CNCs can be tailored to different advanced applications. The proposed research investigates the potential of CNCs as an optically active material. CNCs were tuned to hydroxypropyl nano cellulose (HPNC) with the degree of substitution 1.39. The prepared liquid crystalline HPNC were dispersed in various concentrations of monomethyl ether of polyethylene glycol to get waterborne materials with specific optical anisotropy. The extraction, modification, and morphology of the CNCs were investigated using NMR (Nuclear Magnetic Resonance), TEM (Transmission Electron Microscopy), XRD (X-ray Powder Diffraction), and FESEM (Field Emission Scanning Electron Microscopy) analysis. The prepared HPNC was analyzed using a hot stage POM (Polarized Optical Microscope) for optical anisotropy. The thermal stability of prepared CNCs and HPNC was also investigated. Upon optimization using rheology and POM, it was found that at the ratio of 1:1, HPNC (5 wt%) and mPEG (40 wt%) had the most distinct optical properties. The potential of the prepared materials can be further explored in sensing, smart coating, and security materials.

Microbially induced sedimentary structures and the preservation of vertebrate tracks on the Colorado River delta in Lake Powell, Hite, Utah

Microbially induced sedimentary structures (MISS) increase the preservation potential of vertebrate and invertebrate ichnofossils. The Colorado River forms a delta in Lake Powell at Hite, Utah, and the deltaic shoreline provides a natural laboratory to examine the development of MISS and their influence on vertebrate track preservation. Two types of MISS were identified: pustular and blister. Pustular MISS occur in proximity to the June 2020 high water line. The pustular morphology is characterized by mm-scale small mounds, or pimple-like shapes. Field emission scanning electron microscopy (FESEM) examination identified preserved filamentous cyanobacteria intertwined with fine silt- and clay-sized sediment and well-preserved freshwater diatoms. Branta canadensis (Canada goose) tracks are well developed and they vary from single tridactyl tracks to trampled horizons. Blister MISS, in contrast to pustular MISS, are present in lower elevations, forming in deeper water, greater than 0.5 m. Blisters are mm- to cm-scale irregular mounds that consist of arching mats that are detached from the underlying sediment creating a pore space. Through time the blister mat mounds are destroyed by fragmentation due to desiccation combined with wind processes. FESEM and energy-dispersive spectroscopy system (EDS) analyses indicate the presence of filamentous cyanobacteria on the exterior and palisade Bacillus-type bacteria are in the interior of the blister arch, and gypsum crystals within the mat arch. Freshwater diatoms are present in both mat types. A single human track and multiple trackways of Canis latrans (coyote) were identified on the blister mats. Weakly impressed Canada goose tracks are present. Tracks cross cutting or modifying the pustular MISS have preserved MISS surface textures except in the heavily trampled areas, whereas tracks linked to the blister mat typically do not have reserved mat texture, and usually contain fragmented mat within the impression. Because of fluctuating lake levels and desiccation, these track types had a limited temporal window where they may be produced when moisture conditions permitted MISS development, about two months. Any vertebrates through the area out of the “track window” were not recorded in sediment and mat modification. Tracks imprinted on pustular MISS in lacustrine environments will have a high preservation potential if there are annual fluctuations in lake levels.

Evaluation of adsorption efficiency of activated carbon functionalized with methyl diethanolamine in carbon dioxide gas

Background: Adsorption is a process in which some of the components in the fluid phase, are selectively transferred to the surface of the porous solid particles in the filled bed, which is called the adsorbent. The aim of this study was to examine the adsorption effectiveness of CO2 by activated carbon functionalized with methyl diethanolamine (MDEA), as well as the effects of adsorption temperature, the total pressure of adsorption, and mass of adsorbent. Methods: Activated carbon was first produced using the desired biomasses and suitable activated carbon was chosen. The activated carbon was then functionalized with MDEA amination method. The crystal structure of adsorbents was studied using X-ray diffraction (XRD) methods. In addition, the porosity, specific surface area and structure of prepared activated carbon were measured using BET techniques. Finally, the morphology and strength of the functional groups were measured using Field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FTIR) analyses. Results: The findings of the FESEM and BET analyses for functionalized activated carbon revealed that the specific surface area of the adsorbent increased throughout the chemical and physical modification process, resulting in a BET amount of 725/84 m2 /g. The results showed that the selectivity of the functionalized activated carbon is greater than that of the non-functionalized adsorbent. Conclusion: The adsorption capacity of functionalized activated carbon was 3.98 mmol CO2 g-1 sorbent, compared to 2.587 mmol CO2 g-1 sorbent in the non-functionalized carbon, indicating a 35% improvement in the efficiency of the functionalized sample. According to the findings of the desorption experiments, functionalized carbon shows a 25% decrease in CO2 adsorption efficiency after 20 desorption steps.

Synthesis, characterization, and preliminary in vitro antibacterial evaluation of ZnO nanoparticles derived from soursop (Annona muricata L.) leaf extract as a green reducing agent

Synthesis of zinc oxide nanoparticles (ZnO NPs) was performed using microwave irradiation technique in the presence of Annona muricata L (soursop) leaf extract as a green reducing agent and Zn(NO3)2.6H2O. X-ray diffraction (XRD) characterization verified the structural identity of the ZnO NPs to be hexagonal wurtzite structure. Similarly, Raman spectrum revealed peaks at 109, 447 and 577 cm−1, verifying formation of pristine ZnO NPs. Based on field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) results, the plant extract was found to assist the formation of quasi-spherical nanoparticles with an average size of 37 nm. UV–vis Absorption spectrum indicates that the green-synthesized ZnO NPs absorb at the wavelength centered at 365 nm, corresponding to band gap of 3.39 eV. The Fourier transform infrared (FTIR) spectroscopic findings demonstrate that phytochemicals in the soursop leaf extract are responsible for the formation of ZnO NPs with a sharp and intense characteristic peak at 466 cm−1. The ZnO NPs demonstrated antibacterial activity against two Gram-positive (Bacillus subtilis and Staphylococcus aureus) and two Gram-negative (Klebsiella pneumoniae and Pseudomonas aeruginosa) bacteria with the inhibition zone between 8–15 mm. For all the bacterial strains, the optimal inhibitory concentration of ZnO NPs was determined to be 50 mg/mL. FESEM analysis of S. aureus depicted partial damage and shape distortion of the cells upon treatment with ZnO NPs at 10 mg/mL, thus proving successful antibacterial activity by the green synthesized ZnO NPs. The microwave irradiated, A. muricata L. extract-mediated green synthesis proposed in this work is a fast, economical and effective technique to synthesize ZnO NPs with promising antibacterial activity.

Resourceful and characteristic evaluation of kish graphite in steel mill desulfurization slag

ABSTRACT As steelmakers scale up production to meet the rising demand for steel worldwide, waste generated from steelmaking continues to increase as well. This study adopted sieve analysis and microwave digestion to explore the kish graphite content in the desulfurization slag at a steel mill in southern Taiwan. Moreover, it also explored the physical properties of desulfurization slag through various physical and chemical approaches, such as observing the surface and structure of desulfurization slag using a field emission scanning electron microscope (FE-SEM). First, the results of the sieve analysis indicated that there was 8.51% of kish graphite in the desulfurization slag, which increased substantially to 28.7% after the slag underwent acid digestion. Second, a proximate analysis showed that the desulfurization slag mainly consisted of noncombustible elements, with only a smattering of combustible content. Apart from some kish graphite, the slag was mostly composed of iron-containing materials. Finally, an FE-SEM analysis revealed that the kish graphite’s surface was covered by many impurities, mostly iron oxides, meaning that the amount of carbon content should be slightly lower if an FE-SEM analysis is conducted on kish graphite with cleaner surfaces.

Use of Saponinosomes from Ziziphus spina-christi as Anticancer Drug Carriers.

Saponins are plant glycosides with different structures and biological activities, such as anticancer effects. Ziziphus spina-christi is a plant rich in saponin, and this compound is used to treat malignant melanoma in the present study. Nanophytosomes can be used as an advantageous nanodrug delivery system for plant extracts. The aim of this work is to use the saponin-rich fraction (SRF) from Z. spina-christi and prepare SRF-loaded nanophytosomes (saponinosomes) and observe the in vitro and in vivo effects of these carriers. First, the SRF was obtained from Z. spina-christi by a solvent–solvent fractionation method. Then, Fourier transform infrared (FTIR) analyses were performed to confirm the presence of saponins in the extracted material. Subsequently, the saponinosomes were prepared by the solvent injection method (ether injection method) using a 1:1:1 ratio of lecithin/cholesterol/SRF in the mixture. Characterization of the prepared saponinosomes was performed by FTIR, dynamic light scattering (DLS), field-emission scanning electron microscopy (FE-SEM), and atomic force microscopy (AFM) analyses. In addition, a UV–vis spectrophotometer was used to determine the entrapment efficiency (EE) and in vitro release of the SRF. Finally, cell cytotoxicity of the different formulations was evaluated using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay on both mouse melanoma cells (B16F10) and fibroblasts (L929). Using DLS, AFM, and FE-SEM analyses, the particle size was determined to be 58 ± 6 nm with a zeta potential of −32 ± 2 mV. The calculated EE was 85 ± 3%. The results of the in vitro release profile showed that 68.2% of the SRF was released from the saponinosome after 48 h. The results of the MTT assay showed that the SRF and saponinosomes have high toxicity on B16F10 melanoma cells, but saponinosomes showed a significant decrease in cytotoxicity on L929 fibroblast cells compared with that of the SRF. Our results indicate that the SRF from Z. spina-christi has anticancer activity, and the saponinosomes prepared in this work can control tumor growth, improve therapeutic efficacy, and reduce the side effects of saponins.

Compressive and Shear Strengths of Coir Fibre Reinforced Activated Carbon Stabilised Lateritic Soil

Constructing structures on lateritic soil is challenging in geotechnical engineering due to the various physical and geotechnical characteristics. Many studies investigated different stabiliser materials to strengthen the geotechnical parameters of lateritic soil. This study used activated carbon and coir fibre (ACF) to stabilise lateritic soils as an environmentally friendly binder. Experiments including the unconfined compressive strength (UCS) test and the direct shear test (DST) are performed to investigate the mechanical properties of ACF-stabilised soil for different percentages of activated carbon (AC). Before and after ACF stabilisation, microstructural characterisations of soil samples were performed using field emission scanning electron microscopy (FESEM) and surface-area analysis (BET). The experimental results demonstrate that 3% ACF can considerably enhance the compressive strength, while 2% ACF significantly improves the shear strength, of lateritic soil. Accordant to the UCS results, using fibre in AC-stabilised soil improves post-peak behaviour and residual strength. Moreover, 2% ACF can significantly improve shear strength by creating an interlocking matrix among AC, soil particles, and fibre. The microstructural characterisation based on the findings obtained by FESEM and BET analysis confirms that AC particles fill soil voids. AC restrains the soil movement when exposed to external stresses. In addition, the formation of gel in the stabilised soil matrix binds the soil particles, increasing the strength of the ACF-stabilised soil in comparison with untreated soil.

Biodegradation of Gramineous Lignocellulose by Locusta migratoria manilensis (Orthoptera: Acridoidea)

Exploring an efficient and green pretreatment method is an important prerequisite for the development of biorefinery. It is well known that locusts can degrade gramineous lignocellulose efficiently. Locusts can be used as a potential resource for studying plant cell wall degradation, but there are few relative studies about locusts so far. Herein, some new discoveries were revealed about elucidating the process of biodegradation of gramineous lignocellulose in Locusta migratoria manilensis. The enzyme activity related to lignocellulose degradation and the content of cellulose, hemicellulose, and lignin in the different gut segments of locusts fed corn leaves were measured in this study. A series of characterization analyses were conducted on corn leaves and locust feces, which included field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction pattern (XRD), and thermogravimetric (TG) analysis. These results showed that the highest activities of carboxymethyl cellulase (CMCase), filter paper cellulase (FPA), and xylanase were obtained in the foregut of locusts, which strongly indicated that the foregut was the main lignocellulose degradation segment in locusts; furthermore, the majority of nutritional components were absorbed in the midgut of locusts. The activity of CMCase was significantly higher than that of xylanase, and manganese peroxidase (MnPase) activity was lowest, which might be due to the basic nutrition of locusts being cellulose and hemicellulose and not lignin based on the results of FE-SEM, FTIR, XRD, and TG analysis. Overall, these results provided a valuable insight into lignocellulosic degradation mechanisms for understanding gramineous plant cell wall deconstruction and recalcitrance in locusts, which could be useful in the development of new enzymatic pretreatment processes mimicking the locust digestive system for the biochemical conversion of lignocellulosic biomass to fuels and chemicals.

Experimental Insights into Mesoporous Polyaniline-Based Nanocomposites for Anionic and Cationic Dye Removal.

This work presents the preparation of inorganic-organic hybrid nanocomposites, namely three-dimensional polyaniline (Pani)/activated silica gel (ASG) (3D Pani@ASG), their characterization, and in removing application as a potential adsorbent for cationic brilliant green (BG), crystal violet (CV), and anionic Congo red (CR), and methyl orange (MO) dyes. Pani@ASG nanocomposites have been prepared by the in situ polymerization method and characterized using various techniques such as Fourier transform infrared (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) with selected area electron diffraction, thermogravimetric analysis with derivative thermogravimetry, zeta potential analyses, and Brunauer-Emmett-Teller (BET). The scanning electron microscopy (SEM) study confirms the average particle size of the Pani@ASG nanocomposite is in the range of 5 nm. FESEM, TEM, FTIR, and XRD analysis proved the successful decoration of ASG over Pani. The BET result of Pani@ASG shows a mesoporous nature with a pore diameter of less than 3 nm and a surface area of 423.90 m2 g-1. Both SEM and TEM analyses show the proportional distribution of ASG over Pani's surface. The adsorption trend of BG and MO on the studied materials at pH 7 was found as follows: Pani@ASG > Pani > ASG. The highest sorption capacities of MO and BG on Pani@ASG were 161.29 and 136.98 mg/g (T = 298.15 K, and Pani@ASG dose: 0.04 g for MO and 0.06 g for BG), which were greater compared with bare Pani and bare ASG, respectively. The interaction mechanism behind the adsorption of BG and MO dyes onto the Pani@ASG nanocomposite includes electrostatic interaction, π-π interaction, and hydrogen bonding. The mechanistic pathway and the interactions between the targeted dyes and Pani@ASG were further studied using adsorption isotherm, adsorption kinetics, and thermodynamics.

Synthesis and Characterization of Zinc Oxide Nanoparticles Using Thermophilic Bacteria Isolated from Arid Region of Rajasthan

AbstractFour bacterial strains were used for biosynthesis of zinc oxide (ZnO) nanoparticles (NPs), namely Bacillus tropicus SHJP5, Bacillus tropicus LKJP6, Aeribacillus composti SJP25, and Aeribacillus pallidus SJP28. The synthesized nanoparticles were characterized using UV‐Visible spectroscopy (UV‐Vis), Fourier transform infrared spectroscopy (FTIR), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence spectroscopy (PL), Thermogravimetric analysis (TGA), and X‐ray diffraction (XRD). The XRD pattern of NPs (bio‐synthesized) shows the polycrystalline hexagonal wurtzite structure with the three major planes (100), (002), and (001). The average crystallite size determined by the Debye‐Scherrer equation is between 8–54 nm. A reduction in crystallite size of as‐prepared nanoparticles was observed in the presence of bacterial strains. The FTIR analysis reveals the amide, carboxyl, and hydroxyl groups found on the surface of biosynthesized ZnO NPs. These groups behave as reducing and stabilizing agents. The UV‐Vis spectra reveal the absorption bands for control, SHJP5, LKJP6, SJP25, and SJP28 at 373, 363, 382, 358, and 380 nm respectively. The corresponding energy band gap was found to be 3.324, 3.415, 3.246, 3.463, and 3.263 eV respectively, with the decreasing size of the nanoparticles produced by bacterial strains. The FESEM analysis confirms the hexagonal structure of bio‐synthesized ZnO NPs. The nanoparticles have a uniform distribution of spherical shape except for the strain Aeribacillus pallidus LKJP6 which exhibits uniform and thin nanorods. Minimum inhibitory concentration (MIC) tests against E. coli (7.1 mg/ml) and S. aureus (3.2 mg/ml) verified the antibacterial activity of produced ZnO NPs. The use of isolated strains for the extracellular manufacture of ZnO NPs is encouraged in this work. To the best of our knowledge, this might be the first study that has been presented that shows the structural, optical, and surface morphology of a thermophilic bacterium, Bacillus tropicus SHJP5, Bacillus tropicus LKJP6, Aeribacillus composti SJP25, and Aeribacillus pallidus SJP28 for the biosynthesis of ZnO NPs in particular.

Fabrication And Characterisation of AA6063-T6/SiC/Waste Bone Powder Using Electromagnetic Stir Casting

Electromagnetic stir casting (EMSC) is a highly effective process to produce the metal matrix composite (MMC) because of the uniform mixing of reinforcement with the matrix. The current research is to investigate AA6063-T6/2wt%SiC/5wt%WBP hybrid composite using Microstructure analysis, Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), Energy dispersive X-ray spectroscopy (EDS), Tensile strength and Hardness. Stirring time and speed is kept as constant parameter. Microstructure analysis reveals that there is uniform distribution of reinforcement in AA6063-T6 hybrid composite and no voids were observed. FESEM analysis shows that reinforcement have a good bonding with a small porosity. XRD analysis indicates that there are no unwanted contaminants found and Al3Ca shows the highest peak followed by Al2(CO3)3 and CaSiO3. It was concluded that mechanical properties are improved on adding the reinforcement, tensile strength by 22.4% and hardness by 31%.

Enrichment of biogas through composite membrane of PEBA-1657/ hierarchical T-type zeolite

Presently, composite membranes emerged as a promising approach to overcome the limitations of polymeric and inorganic membranes particularly in acid gas separation. In the present work, composites membranes were fabricated by combining hierarchical T-Type (h-zeolite T) zeolite and PEBA-1657 at different filler composition that ranging from 5 wt% – 30 wt% for the CO2/CH4 separation. The physicochemical properties of the resultant inorganic filler and membranes were investigated by using Brunauer-Emmett- Teller (BET), field emission scanning electron microscopy (FESEM), Fourier Transform infra-red (FTIR), x-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). FESEM and EDX analysis revealed that the formation of voids and agglomeration of particles is pronounced as the fillers loading was increased up to 30 wt%. The single gas permeation test demonstrated that amalgamation of h-zeolite T particles into PEBA-1657 has resulted in the improvement of CO2 permeability up to 122% and CO2/CH4 selectivity up to 31%. Hybrid membrane encapsulated with 25 wt% of h-zeolite T displayed a maximum separation efficiency with the highest CO2 permeability of 164.83 Barrer and CO2/CH4 selectivity of 19.37. However, further increment of fillers composition up to 30 wt% resulted in a sharp reduction of CO2/CH4 selectivity to 15.80 due to the particles sedimentation and agglomeration. Overall, the favorable gas transport behavior of PEBA-1657/h-zeolite T composite membrane indicates its promising prospect for CO2/CH4 separation especially in biogas and natural gas purification application. Future research efforts are directed on the optimization of the fabrication parameters and performance investigation at different operating condition to further enhance the CO2 separation and extend its operability under various environment.

Effect of Morphology and Concentration of Two Carbon Allotropes on the Enhancement of Specific Heat Capacity of Eutectic Molten Salt

Abstract This study aims at investigating the effect of nanoparticle morphology and concentration on the specific heat capacity of a molten salt used as thermal energy storage material in concentrated solar power plants. Binary carbonate salt eutectic (lithium carbonate and potassium carbonate at a molar ratio of 62:38, respectively) is used as the base material. Two different carbon allotropes, graphite nanoparticles (Gp) and carbon nanotube (CNT) are used as dopants to look into the morphological effect on specific heat (Cp). A series of experiments are carried out to systematically investigate the effect of nanoparticle concentration by varying the mass percentages of carbon allotropes (2 wt.%, 4 wt.%, and 6 wt.%) in the base material. The specific heat capacity of the samples is measured both in solid (250 °C and 400 °C) and liquid phases (520°–560 °C) using a differential scanning calorimeter (DSC). The results show a maximum enhancement of 35% in Cp for 6 wt.% Gp -based salt in the liquid phase. CNT-based nanomaterials exhibit a maximum enhancement of 20% for 4 wt.% CNT inclusion in the liquid phase. The superior performance of Gp compared to CNT and mass concentration-controlled specific heat is explained using field emission scanning electron microscope (FESEM) and energy-dispersive X-ray spectroscopy (EDS) analysis. FESEM and EDS analysis confirm the presence and the composition of the compressed layer, respectively. These layers are considered to be responsible for the anomalous increase in specific heat capacity at different mass concentrations for the carbon allotropes.

Isolation and characterization of lignin-rich particles as byproducts of bioethanol production from wheat straw to reinforce starch composite films

Bioethanol was produced from wheat straw by a concentrated alkali pretreatment at specific conditions with a yield of 88 g ethanol per 1 kg of dry straw. To economically improve the bioethanol production process and valorize residual waste, the lignin-rich solid waste particles were isolated from the pretreatment waste liquid and characterized, and finally employed to reinforce starch-based biodegradable film. The solid waste particles were characterized by chemical analysis, dynamic light scattering (DLS), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). As bioethanol byproducts, they have mainly contained 88 wt% lignin. The average diameter of the uniform spherical shape extracted particles was determined to be 160 nm by DLS and FESEM. The presence of syringyl and guaiacyl rings were conducted by FTIR. Due to their suitable mechanical performance and thermal resistance, the lignin nanoparticles were employed as reinforcement for green biodegradable starch films. To prepare films, suspensions containing starch, glycerol, and different concentrations of lignin (0–30 wt%) were molded by the solution casting process. The starch-lignin composite films were analyzed by mechanical tensile tests, crystallinity analysis, FESEM, and thermal analysis. From the results, it was found that by adding 20 wt% lignin particles, the tensile strength and modulus of the pure starch film were increased from 4.8 and 0.9–8 and 2.4 MPa which can be partially explained due to crystallinity enhancement of film from 29 % to 48.3 %. In addition, the thermal resistance and the hydrophilic property of the composite films were enhanced due to lignin nanoparticle presence. It can be concluded that the isolation of lignin nanoparticles as waste solid in bioethanol production could be considered as a promising stage in the sustainability of second-generation products from the bioethanol production process.

Improvement of the dual barrier/active corrosion inhibition function of the epoxy composite filled with zinc doped-phytic acid-modified graphene oxide nanosheets

In this research, a smart epoxy coating was designed using GO sheets functionalized (non-covalently) with phytic acid (Ph) molecules and zinc (II) cations. Ultraviolet-visible spectroscopy (UV–Vis), Raman spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and inductively coupled plasma (ICP) were conducted to prove the adsorption of inhibiting species on the GO surface. Alongside the electrochemical impedance spectroscopy (EIS) and polarization methods, grazing incidence XRD (GI-XRD) and FE-SEM analyses were carried out on the plates exposed to the modified GO-containing solutions. The coated samples were subjected to the EIS, salt spray test (SST), pull-off, and cathodic delamination (CD) methods. The characterization analyses confirmed the adsorption of the Zn2+ cations and Ph molecules. The adequate inhibition efficiency of the GOZn400Ph nanosheets in the saline solution was verified by the electrochemical techniques. The GOZnPh/EP coating exhibited the highest low-frequency impedance value after 49 days (~109 Ω cm2). In addition to the superior barrier protection properties, the GOZnPh nanosheets promoted active protection ability. The inclusion of the GOZnPh increased the dry adhesion strength and reduced the adhesion loss.

Effect of praseodymium in cation distribution, and temperature-dependent magnetic response of cobalt spinel ferrite nanoparticles

This work reports cation distribution, magnetic, structural, and morphological studies of rare-earth Pr doped cobalt ferrite nanoparticles CoFe2−x Pr x O4 (x = 0, 0.02, 0.04, 0.06 at%) fabricated by sol-gel auto-combustion method. X-ray diffraction analysis, field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and Fourier-transform infrared (FTIR) microscopy were utilized to study the structural and morphological characteristics of the prepared samples. Rietveld refinement by the Material Analyses Using Diffraction (MAUD) software showed the formation of mono-phase cubic spinel structure with Fd-3m space group; however, there was a trace of impure PrFeO3 phase for the sample CoFe1.96Pr0.04O4 (x = 0.06). Cation distribution was inferred from the XRD patterns using MAUD program. FESEM analysis revealed the spherical-shaped particles with dimensions close to the data extracted from XRD analysis and HRTEM images confirmed it. FTIR measurements revealed the presence of two prominent stretching vibrational modes confirming the successful formation of ferrite spinel structure. Magnetic properties of the nanoparticles were measured at two different temperatures 300 K and 10 K. For the low temperature of 10 K a high sensitive measurement method as Superconducting Quantum Interference Device (SQUID) magnetometry was used and Vibrating Sample Magnetometer (VSM) recorded the magnetic data at 300 K. Comparison of the magnetic results exhibited a significant enhancement with temperature drop due to the reduction in thermal fluctuations. Paramagnetic nature of rare-earth ions may be the main reason for M S decrement from 76 emu g−1 (x = 0.0) to 60 emu g−1 (x = 0.02) at 300 K. At 10 K, the estimated cation distribution played a vital role in justification of obtained magnetic results. All the obtained data showed that the synthesized magnetic nanoparticles can be implemented in permanent magnet industry and information storage fields, especially when it comes to lower temperatures.

Elastic properties and pore structure characterization of selected shales in the sungai Perlis beds, Terengganu, Peninsular Malaysia

Studied drill core of the Sungai Perlis Beds in the Terengganu State, Peninsular Malaysia, consists of a diverse suite of organic rich shale lithofacies at various subsurface depths. Lithofacies were delineated on the basis bedding thickness, mineralogy, and organic richness carried out by X-ray diffraction and (XRD) total organic content (TOC) analysis. Field-emission scanning electron microscopy (FE-SEM) analysis was carried out to identify the pore structure, range of pore sizes and mineral arrangement within each lithofacies unit Elastic geomechanical properties (Young’s modulus and Poisson’s ratio) were measured on core samples from each lithofacies unit using static and dynamic approaches. The identified lithofacies include moderate TOC massive argillaceous shale (MTOCMAS), high TOC massive argillaceous shale (HTOCMAS) and high TOC massive siliceous shale (HTOCMSS). FE-SEM analysis shows that pores in all the lithofacies are mostly intergranular, associated with phyllosilicate minerals, and ranges from <1 micrometer to approximately 8 micrometer. Static and dynamic elastic properties measurement shows that shale lithofacies having a high content of phyllosilicate minerals has a lower Young’s modulus and a high Poisson’s ratio value while lithofacies rich in brittle minerals has a higher Young’s modulus and a low Poisson’s ratio value. A good correlation exists between mineralogical brittleness index of the lithofacies and their plane strain modulus. The plane strain modulus is found higher in lithofacies having abundance of brittle minerals in the matrix suggesting that the high TOC massive siliceous shale (HTOCMSS) would preferably allow formation of dense hydraulic fractures, as observed in the CT scan analysis of triaxially fractured specimen, compared to argillaceous shale lithofacies.

Nanoparticle Production of Zingiber officinale Roscoe Rhizome Extracts by ESS (Expansion of Supercritical Solution)

Aims: To propose a modified RESS method of herbal pharmaceutical extracts nanoparticle production. Background: A vast number of methods have been applied to water-insoluble pharmaceuticals to improve their solubility. Nanoparticle production of pharmaceuticals is considered as one of the high-speed ways to improve solubility. Objective: Supercritical CO2 was applied to extract Zingiber officinale Roscoe rhizome pharmaceutical. Then, a modified RESS (Rapid Expansion of Supercritical Solution) method, called ESS (Expansion of Supercritical Solution), was exerted to obtain NPs (nanoparticles) of the extracted pharmaceuticals. Methods: Initially, applying high pressure in supercritical CO2 contributed to the extract dissolution such that supercritical CO2 was saturated with the sample. Then, by decreasing the pressure, an expansion occurred in the saturated medium. This expansion reduced the power of supercritical CO2 solvent and induced the sample nanoparticle nucleation in the needle valve. Results: LC-MS (Liquid Chromatography-Mass Spectrometry) and EDX (energy dispersive X-ray spectroscopy) result provided solid evidence for the presence of anti-cancer pharmaceutical, [6]-Gingerol, in the extract. The medium size of the nanoparticles in FESEM (Field Emission Scanning Electron Microscopy) analysis was 36 nm. The most satisfactory parameters for a 2 mg mL-1 feeding solution were the initial pressure of 350 atm, secondary pressure of 160 atm, equilibrating time of 10 min, precipitating time of 20 min, and temperature of 48 °C. Conclusion: Unlike rapid expansion of supercritical solution methodology, in this technique, the initial and secondary pressures were permanently above the critical pressure to provide a gentle expansion, which contributes to the production of uniform and small particles. The obtained uniform NPs had a narrow size distribution. Consequently, ESS technique can be considered as an efficient technique for improving the solubility of hydrophobic pharmaceuticals, such as [6]-gingerol.