Fourier Transmission Infrared Spectroscopy Research Articles

Isolation of bioactive compounds from lichen Parmelia sulcata and evaluation of antimicrobial property

BackgroundLichens were used as an ailment in the traditional medicine for treating various disorders for centuries. Since there is less evidence in the literature about the medicinal property of Parmelia sulcata (P. sulcata), we made a pioneer attempt to explore the antioxidant and antimicrobial properties of lichens. MethodsIn the present study, the three Samples were collected by using the column chromatography by elucidating the ethyl acetate extract of P. sulcata, and the samples were subjected to DPPH and ABTS assays to find the free radical scavenging activity, total phenols and flavonoids were estimated. The minimum inhibitory concentration was evaluated against the bacterial species (Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Klebsiella pneumoniae) and fungal species (Candida albicans and Aspergillus fumigatus) by the microdilution method. The best activity sample was analyzed using the Gas Chromatography–Mass Spectrometry (GC–MS), Fourier Transmission Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR). ResultsThe results shown that all the samples contain phenols and flavonoids which are responsible for antioxidants, antibacterial and antifungal activities. Among that sample-3 shown best antimicrobial activity and it was analyzed and identified as 7-hydroxy-3-(2-methylbut-3-en2-yl)-chromen-2-one. ConclusionThe outcome of the study suggests that sample-3 shown good antimicrobial activity and identified as 7-hydroxy-3-(2-methylbut-3-en2-yl)-chromen-2-one. It can be a resource for further studies.

Design and development of flexible humidity sensor for baby diaper alarm: Experimental and theoretical study

Solvent-free synthesis of nanocomposite for flexible humidity sensor is gaining immense interest to fulfill the criteria for its practical application. Herein, present paper reports the development of cadmium sulfide/polyacrylamide nanocomposite as a flexible humidity sensor, which was fabricated by the facile spin-coating technique on PET (polyethylene terephthalate) substrate. Morphological, optical and crystalline nature of CdS/polyacrylamide nanocomposite were investigated using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), differential scanning calorimetric (DSC), Fourier transmission infrared spectroscopy (FTIR), UV–Visible, and Particle size analysis. Characteristic surface area and pore volume were estimated using BET analysis whereas the hydrophilicity of the sample was investigated using contact angle measurement. As fabricated sensor showed an outstanding humidity sensing response with good linearity in the humidity ranging from 11% to 95%RH. The sensitivity of nanocomposite at high humidity range (50–95%RH) was calculated as 306.47 nF/%RH and is utilized for moisture detection of commonly used baby diapers with alarm. The simulated & optimized computer model of the synthesized composite (Cd-S & Polyacrylamide) using density functional theory and performed several analyses. HOMO-LUMO and correspondingly obtained other electronic parameters were evaluated, which revealed that band gap of the synthesized composite material tends to decrease upon increasing the level of water molecules owing to be better humidity sensing mechanism, and therefore, can be used as humidity sensor.

On synergistic effect of BaTiO3 and graphene reinforcement in polyvinyl diene fluoride matrix for four dimensional applications

This work presents the synergistic effect of BaTiO3 and graphene (Gr) reinforcement in polyvinyl diene fluoride (PVDF) matrix by chemical-assisted mechanical blending (CAMB) for possible 4D applications. The PVDF matrix was prepared (in form of filament) by solvent casting followed by twin-screw extrusion (TSE) as CAMB process. The filament was used on fused deposition modelling (FDM) setup for preparing standard flexural and pull-out specimens. The mechanical testing revealed that the parts printed with 100% in-fill density (ID), 70 mm/s infill speed (IS), and 45° in-fill angle (IA) has shown better flexural strength (FS). For pull-out properties, part printed at IS 90 mm/s, 0° IA, and 100% ID have shown better results. Further optimized settings of FS were used to 3D print thin cylindrical discs followed by electric poling (for possible piezoelectric properties). The results of X-ray diffraction (XRD) and Fourier transmission infrared spectroscopy (FTIR) analysis show more β-phase formation in the electrically poled sample as compared to non-poled specimen. Moreover, XRD spectra show the homogenous dispersion of doped material in the PVDF matrix. The piezoelectric coefficient (d33) 30.2pC/N was observed on 3D printed specimen (prepared from filament processed with CAMB), suitable for 4D applications.

Green synthesis of zero-valent iron nanoparticles and loading effect on activated carbon for furfural adsorption

The adsorption techniques are extensively used in dyes, metronidazole, aniline, wastewater treatment methods to remove certain pollutants. Furfural is organic in nature, considered a pollutant having a toxic effect on humans and their environment and especially aquatic species. Due to distinct characteristics of the adsorption technique, this technique can be utilized to adsorb furfural efficiently. As an environmentally friendly technique, the pomegranate peel was used to synthesized activated carbon and nanostructure of zerovalent iron impregnated on the synthesized activated carbon. The physicochemical and crystallinity characterization was done using Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), and Field emission scanning electron microscopy (FESEM). The nanoparticles are porous in structure having 821.74 m2/g specified surface area. The maximum amount of the adsorbent pores in the range of 3.08 nm shows the microporous structure and enhancement in adsorption capacity. The effects of increment in concentration of adsorbent, pH, reaction contact time and adsorbent dose, isothermal and kinetic behaviour were investigated. At the UV wavelength of 227 nm furfural adsorption was detected. The separation of the furfural from the aqueous solution was calculated at the 1 h reaction time at the composite dosage of 4 g/L, 250 mg/L adsorbent concentration and pH kept at 7. The 81.87% is the maximum removal attained by the nanocomposite in comparison to the activated carbon is 62.06%. Furfural adsorption was also analyzed by using the equations of isothermal and kinetics models. The adsorption process analysis depends on the Freundlich isotherm and Intra-particle diffusion than the other models. The maximum adsorbent of the composite was determined by the Langmuir model which is 222.22 mg/g. The furfural removal enhances as the adsorbent dose enhances. The developed zerovalent iron nanoparticles incorporated on activated carbon (AC/nZVI) from pomegranate peel extract are feasible as an efficient and inexpensive adsorbent to eliminate furfural from a liquid solution.

Bio-mimetic synthesis of catalytically active nano-silver using Bos taurus (A-2) urine

Herein we have synthesized silver nanoparticles (Ag NPs) using liquid metabolic waste of Bos taurus (A-2 type) urine. Various bio-molecules present in cow urine, are effectively used to reduce silver (Ag) ions into silver nanoparticles in one step. This is bio-inspired electron transfer to Ag ion for the formation of base Ag metal and is fairly prompt and facile. These nanoparticles act as a positive catalyst for various organic transformation reactions. The structural, morphological, and optical properties of the as-synthesized Ag NPs are widely characterized by X-ray diffraction spectroscopy, ultraviolet–visible spectroscopy, scanning electron microscope, Fourier transmission infra-red spectroscopy, and atomic force microscopy. The as-synthesized bio-mimetic Ag NPs show potential activity for several reduction reactions of nitro groups. The Ag NPs were also used for degradation of hazardous dyes such as Methylene blue and Crystal violet with good degradation rate constant.

Removal of a reactive dye from simulated textile wastewater by environmentally friendly oxidant calcium peroxide

Abstract In the present study, calcium peroxide (CaO2) was used separately for potential application as an environmentally friendly and low-cost oxidant for the removal of a textile dye ‘Reactive Black 5’ (RB5) from simulated textile wastewater containing auxiliary chemicals of textile production. The specific morphology, elemental analysis, particle size distribution, specific surface area, identification of crystalline phases and surface functional groups of the synthesized CaO2 were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), laser diffraction (LD), Brunaure–Emmett–Teller method (BET), X-ray diffraction (XRD) and Fourier transmission infrared (FTIR), respectively. X-ray Diffraction analysis confirmed the synthesized oxidant as CaO2 with the tetragonal crystalline structure. The signal corresponded to a bending vibration of O–Ca–O was detected in the fingerprint region of the FTIR spectroscopy. The effects of various independent parameters such as contact time, pH, initial RB5 concentration and CaO2 dosage on decolorization were investigated. The results of the study showed that pH, initial dye concentration and the CaO2 amounts have significant effects on removal of the RB5. The optimum pH was determined 7 for the removal of RB5 by CaO2. 2.0 g CaO2 was found to be sufficient for the removal of 300 mg/L RB5 with 96.93% removal efficiency. Also 82.8% chemical oxygen demand (COD) removal efficiency from simulated textile wastewater (STW) was obtained by 2.0 g CaO2. The results of the present study showed that the CaO2 can be used as an environmentally friendly and low-cost oxidant for effective removal of reactive textile dyes.

Metal‐Free g‐C3N4/Graphite Composite Based Carbocatalyst for Epoxidation of Styrene

AbstractTuning graphitic surface with nitrogen functionalities renders potential carbocatalysts for a wide range of reactions. Herein, g‐C3N4/graphite composite material (g‐C3N4@G) is reported for oxidation of styrene to styrene oxide. The detailed physiochemical properties of g‐C3N4@G are investigated by X‐ray photoelectron spectroscopy (XPS), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), X‐ray diffraction (XRD) and Fourier transmission infrared spectroscopy (FTIR) analysis. The TEM and SEM micrographs indicate the formation of g‐C3N4 sheets and N1s XPS results confirm the formation of g‐C3N4 on the graphitic surface. The role of specific catalytic sites is experimentally studied by the use of model catalysts those mimic the functional groups on the surface of g‐C3N4@G. It is suggested that the catalytic sites on the surface showcase a synergeistic effect, with sp2 hybridized N site being most selective for styrene oxide.

Synthesis and characterization of multi functional nickel ferrite nano-particles for X-ray/gamma radiation shielding, display and antimicrobial applications

In the present communication, NiFe2O4 (NFO) nanoparticles (NPs) are synthesized by using solution combustion method. To know the phase purity, functional group, surface morphology, structural analysis and energy band gap, the synthesized sample was characterized by using the techniques such as powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR) and UV–Visible spectrophotometer. The Bragg's reflection of PXRD confirms the formation of cubic NFO NPs with Fd − 3 m space group. The SEM morphology shows the distribution of irregular shaped agglomerated NFO NPs and EDAX confirms the presence of Ni, Fe and O elements and absence of other impurities. The concentric circles observed in SAED pattern confirms the high crystallinity nature and the estimated crystallite size matches well with that of the crystallite size calculated from Scherrer's equation. The direct energy band gap calculated using Tauc's relation is found to be 5.2 eV. Further, the X-ray/gamma ray shielding properties of NFO NPs in the energy range 0.081–1.332 MeV using NaI (Tl) detector and multi channel analyzer (MCA) were measured. The measured shielding parameters are compared with the theory. Above 356 keV energy of X-ray/gamma ray, the measured shielding parameters agrees well with the theory, whereas slight deviation is observed below 356 keV. This deviation is mainly due to the influence of atomic size of the target medium. Hence, we can conclude that an accurate theory is necessary to explain the interaction of X-ray/gamma with the nano size atoms. The photoluminescence emission spectra consists of peaks at 448, 540 and 628 nm. The CIE and CCT coordinates clearly confirms that the present nanophosphor might find applications in display/cool white light LEDs. Furthermore, antimicrobial activity of synthesized NFO NPs are also studied. Viability test was conducted on two food borne pathogens such as Bacilluscereus and Pseudomonasaeruginosa. The material showed fairly good antimicrobial activity compared to streptomycin which was used treat a number of bacterial infections. Thus NFO material may unfold new prospects in the fields like shielding of X-ray/gamma ray, display and biomedical applications.

Potential Application of Peppermint (Mentha piperita L.), German Chamomile (Matricaria chamomilla L.) and Yarrow (Achillea millefolium L.) as Active Fillers in Natural Rubber Biocomposites

In this study, peppermint (Mentha piperita L.), German chamomile (Matricaria chamomilla L.) and yarrow (Achillea millefolium L.) were applied as natural fibrous fillers to create biocomposites containing substances of plant origin. The purpose of the work was to investigate the activity and effectiveness of selected plants as a material for the modification of natural rubber composites. This research was the first approach to examine the usefulness of peppermint, German chamomile and yarrow in the field of polymer technology. Dried and ground plant particles were subjected to Fourier transmission infrared spectroscopy (FTIR) and UV–Vis spectroscopy, thermogravimetric analysis (TGA), goniometric measurements (contact angle) and scanning electron microscopy (SEM). The characterization of natural rubber composites filled with bio-additives was performed including rheometric measurements, FTIR, TGA, cross-linking density, mechanical properties and colour change after simulated aging processes. Composites filled with natural fillers showed improved barrier properties and mechanical strength. Moreover, an increase in the cross-linking density of the materials before and after the simulated aging processes, compared to the reference sample, was observed.

A strategy for mitigating avian colibacillosis disease using plant growth promoting rhizobacteria and green synthesized zinc oxide nanoparticles.

Avian colibacillosis caused by the zoonotic pathogen Escherichia coli is a common bacterial infectionthat causes major losses in the poultry sector. Extracts of different medicinal plants and antibiotics have been used against poultry bacterial pathogens. However, overuse of antibiotics and extracts against pathogenic strains leads to the proliferation of multi-drug resistant bacteria. Due to their environmentally friendly nature, nanotechnology and beneficial bacterial strains can be used as effective strategies against poultry infections. Green synthesis of zinc oxide nanoparticles (ZnO-NPs) from Eucalyptus globulus leaves was carried out in this study. Their characterization was done by UV-vis spectroscopy, X-ray diffraction (XRD), and Fourier transmission infrared spectroscopy (FT-IR) which confirmed their synthesis, structure, and size. In vitro, antimicrobial activities of plant leaf extract, ZnO-NPs, and plant growth-promoting rhizobacteria (PGPR) were checked against E. coli using well diffusion as well as disc diffusion method. Results proved that the antimicrobialactivity of ZnO-NPs and PGPR strains was more enhancedwhen compared to eucalyptus leaf extract at 36 h. The maximum relative inhibition shown by ZnO-NPs, PGPR strains and eucalyptus leaf extracts was 88%, 67% and 58%, respectively. The effectiveness of ZnO-NPs was also increased with an increase in particle dose and treatment time. The 90 mg/ml of ZnO-NPs was more effective. PGPR strains from all over the tested strains, Pseudomonas sp. (HY8N) exhibited a strong antagonism against the E. coli strain as compared to other PGPR strains used in this study. However, combined application of PGPR (Pseudomonas sp. (HY8N)) and ZnO-NPs augment antagonistic effects and showed maximum 69% antagonism. The study intends to investigate the binding affinity of ZnO-NPs with the suitable receptor of the bacterial pathogen by in silico methods. The binding site conformations showed that the ligand ZnO binds with conserved binding site of penicillin-binding protein 6 (PBP 6) receptor. According to the interactions, ZnO-NPs form the same interaction pattern with respect to other reported ligands, hence it can play a significant role in the inhibition of PBP 6. This research also found that combining ZnO-NPs with Pseudomonas sp. (HY8N) was a novel and effective technique for treating pathogenic bacteria, including multidrug-resistant bacteria.

CHARACTERIZATION OF ZINC OXIDE NANOPARTICLES SYNTHESIZED BY OLEA EUROPAEA LEAVES EXTRACT (PART L)

The current study was aimed to synthesized zinc oxide nanoparticles (ZnONPs) using aqueous extract of olive leaves (OLE), which is very simple and eco-friendly method. ZnONPs were formed by dissolving of OLE in zinc oxide solution with adjusted pH to 12. Zinc acetate dehydrate reduced to ZnONPs during mixing with OLE associated with change of the color solution from white to pale yellow color within a few minutes. The synthesized OLEZnONPs were separated by centrifugation (4000rpm/ 5min) , then characterized by Fourier Transmission Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD) and Field emission-Scanning Electron Microscopy (FE-SEM) methods. The results of FT-IR showed that the functional group related to Zn-O at (433.98 to 416.67 cm_1), whereas X-RD at 2 theta diagnose the type of oxide formation as ZnO and determined particle size in range (20 – 30 nm). Besides, SEM image was showed the presence of hexagonal shape of ZnO nanoparticles (42.87nm). Therefore, the biogenic synthesis of zinc oxide nanoparticles using Olea Europaea leaves was simple, low coast, can be an alternative to chemical synthesis and the possibility of using in biomedicine field

Mechanical and Optical Properties of Amorphous SiN-Based Films Prepared By ECR PECVD and CCP PECVD

Hydrogenated amorphous silicon nitride (a-SiN:H) and silicon carbonitride (a-SiCN:H) films grown by plasma enhanced chemical vapor deposition (PECVD) are widely investigated for their interesting optical and electrical properties [1]. In this work, we discuss the effect of the deposition power on SiN-based films during plasma deposition. The influence on the optical and mechanical properties of the films was investigated. In order to study this issue on a broader basis, two types of plasmas were applied to deposit 0.5 to 1.5 μm a-SiN:H and a-SiCN:H films. First, a-SiN:H and a-SiCN:H films were deposited by electron cyclotron resonance (ECR) PECVD using the same deposition parameters for all films. During the deposition process, the carbon content in the a-SiCN:H thin films was introduced into the chamber through a pure CH4 gas source to avoid any perturbation on the deposition pressure. Second, a-SiN:H films were deposited by a capacitively coupled plasma reactor CCP PECVD using a SiH4/NH3/N2/Ar precursor mixture. In both deposition processes, the ion bombardment energy was tuned only by the deposition power. The mechanical properties of the films were determined ex-situ by profilometry to evaluate the residual stress using the wafer curvature method and by nanoindentation to determine Young’s modulus and hardness of the films. The thickness and the refractive index were measured by variable angle spectroscopic ellipsometry (VASE). It was observed that the evolution of the residual stress according to the deposition power in the ECR PECVD was different from the CCP PECVD. Besides, we notice a slight increase in the refractive index when the residual stress becomes more compressive as illustrated in figure 1 for a-SiN:H and a-SiCN:H films. Through this discussion, we try to have a better understanding of the different interactions taking place when the deposition power increases in terms of ion bombardment energy. Then, we will study the effect of ion bombardment on the film structure based on the composition and structure of the films and the hydrogen bond concentration measured by Fourier transmission infrared spectroscopy (FTIR). In addition, we have also investigated the influence of carbon incorporation on a-SiN:H thin film properties. We notice a decrease in the refractive index and an increase in the compressive residual stress caused by the carbon incorporation.[1] A. Abdelal, Z. Khatami, and P. Mascher, “Optical and Electrical Properties of ECR-PECVD Grown SiCN Thin Films,” ECS Meet. Abstr., vol. MA2018-01, no. 17, p. 1189, Apr. 2018, doi: 10.1149/ma2018-01/17/1189. Figure 1

Synthesis of diosgenin conjugated gold nanoparticles using algal extract of Dictyosphaerium sp. and in-vitro application of their antiproliferative activities

In this study, gold nanoparticles (AuNPs) and novel gold nanoformulations loaded with diosgenin (Dio-AuNPs) were synthesized through green approach using algal extract from Dictyosphaerium sp. strain DHM2 (LC159306) as a reducing agent. AuNPs and Dio-AuNPs synthesized were characterized through UV–vis spectroscopy, zeta potential analysis, FT-IR spectroscopy, X-ray diffraction (XRD) analysis and scanning transmission electron miroscopy. An average zeta potential value of -32.4 mV indicated that AuNPs were highly stable. Fourier transmission infrared spectroscopy (FT-IR) of AuNPs showed the presence of hydroxyl groups and carbonyl groups alongwith various other capping and stabilizing functional groups. Also, in FT-IR spectrum of Dio-AuNPs characteristic peaks of both AuNPs and diosgenin were observed. XRD analysis of AuNPs and Dio-AuNPs showed that both nanostuctures exist in the crystalline form. Scanning transmission electron microscopy (STEM) studies revealed that AuNPs and Dio-AuNPs had spherical morphology with average size range of 7.9 ± 2.4 nm and 10.3 ± 2.4 nm, respectively. Moreover, in-vitro antiproliferative activities of AuNPs and Dio-AuNPs were determined on colorectal cancer cell line HCT116 and breast cancer cell line HCC1954 using sulforhodamine B (SRB) proliferation assay. Dio-AuNPs were extremely potent with GI50 values of 1.03 ± 0.27 μg/mL and 1.69 ± 0.18 μg/mL in HCT116 and HCC1954 cell lines, respectively. AuNPs however, were almost 18 fold less potent as compared to Dio-AuNPs in both the cell lines. The current study has demonstrated biological synthesis, characterization and antiproliferative activities of gold nanoparticles and novel diosgenin loaded gold nanoformulations in colorectal and breast cancer cell lines and provided evidence that anticancer activities of both diosgenin and AuNPs can be enhanced many folds when used in conjugation.

Study on Gelatin/Hydroxyapatite/Chitosan Material Modified with Osteoblast for Bone Bioengineering

Designing of a suitable ‘cell-material’ construct has enabled the regeneration of bone. It was in accordance with the increasing demand for the repair of defective and/or diseased bone tissue. In this research, the relative behavior of the osteoblast-seeded materials was demonstrated. It enabled the selection of the cell-material system for rabbit bone bioengineering studies. Significant role of polypeptide-polymer-ceramic-cell material in bone tissue engineering was shown. The properties of natural polymer-based scaffold were attributed to their origin and chemical modifications. In this study, the lyophilized osteoblast-material conjugate was designed and characterized extensively. The same was done by physicochemical measurement, for surface and core morphology analysis. The atomic force microscopy (AFM) and transmission electron microscopy (TEM) data from these conjugates have shown surface parameters. The surface suitable for cell attachment and proliferation along with uniform interconnected porous morphology was selected. The calcium to phosphate proportion-based energy-dispersive X-ray was done. It defines the inorganic content in these composites. The crystal spots were found from the selected area electron diffraction pattern. It had supported the insights from the physicochemical measurements. AFM and TEM micrographs have shown surface and core morphology with median surface roughness of 14.96 nm and uniform porous architecture, respectively. Fourier transmission Infra-red spectroscopy and X-ray diffraction had confirmed the formation of mineral deposits within the scaffolds. The subsequent in vitro study has revealed that among the biomaterials, ‘gelatin in hydroxyapatite-coated chitosan matrix’ has prominence over ‘gelatin-hydroxyapatite.’ It was confirmed only after seeding them with the rabbit ‘iliac crest-derived’ osteoblast. Two types of rabbit osteoblast derivatives were used. They are the osteoblast from the bone tissue (rT) and osteoblast obtained after Mesenchymal stem cell (MSCs) differentiation. Bone marrow was the source of MSCs. This ‘rT-seeded’ biomaterial was found appropriate for bone bioengineering applications.

Common Nettle (Urtica dioica L.) as an Active Filler of Natural Rubber Biocomposites.

Common nettle (Urtíca Dióica L.), as a natural fibrous filler, may be part of the global trend of producing biocomposites with the addition of substances of plant origin. The aim of the work was to investigate and explain the effectiveness of common nettle as a source of active functional compounds for the modification of elastomer composites based on natural rubber. The conducted studies constitute a scientific novelty in the field of polymer technology, as there is no research on the physico-chemical characteristics of nettle bio-components and vulcanizates filled with them. Separation and mechanical modification of seeds, leaves, branches and roots of dried nettle were carried out. Characterization of the ground plant particles was performed using goniometric measurements (contact angle), Fourier transmission infrared spectroscopy (FTIR), themogravimetric analysis (TGA) and scanning electron microscopy (SEM). The obtained natural rubber composites with different bio-filler content were also tested in terms of rheological, static and dynamic mechanical properties, cross-linking density, color change and resistance to simulated aging processes. Composites with the addition of a filler obtained from nettle roots and stems showed the highest mechanical strength. For the sample containing leaves and branches, an increase in resistance to simulated ultraviolet and thermo-oxidative aging processes was observed. This phenomenon can be attributed to the activity of ingredients with high antioxidant potential contained in the plant.

Formation and Phase Selection of CaCO3 in the Intervention of Lignin Monomer Model Compounds

AbstractThe single crystal form and uncontrollable topography of CaCO3 in nature severely restrict its product grade and application. Meanwhile, lignin is still not utilized efficiently. In order to improve this, three types of lignin monomer model compounds as p‐coumaric acid (PCA), ferulic acid (FA), and sinapic acid (SA) are employed to induce the growth of CaCO3 to investigate the relationship between lignin structure and CaCO3 crystallization. The synthesized PCA and CaCO3 composite crystals (PC‐ACCs), FA and CaCO3 composite crystals (F‐ACCs), and SA and CaCO3 composite crystals (S‐ACCs) are characterized by field emission scanning electron microscope (FESEM), X‐ray diffraction (XRD), and Fourier transmission infrared spectroscopy (FTIR) to ascertain their molecular structures and crystal information. The growth rule of the acid and CaCO3 composite crystals (ACCs) induced by the three units is also explored. The results show that the vaterite and calcite of ACCs can be formed selectively. In the presence of PCA, FA, and SA, pH is the key factor on the phase selection of ACCs. The temperature and organic acid type also play important roles on the formation of CaCO3. The ACCs present distinguishing surface topographies at different temperatures. The number of methoxyl in the PCA, FA, and SA decides the phase ratio of vaterite and calcite in the ACCs.

Biosynthesis of metallic nanoparticles from waste Passiflora edulis peels for their antibacterial effect and catalytic activity

Recently, the waste agricultural materials have been widely considerable for green synthesis of noble metallic nanoparticles (MNPs) due to cost efficiency and environmental protection. This study has presented a simple method for the preparation of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) utilizing aqueous extract of waste Passiflora edulis peel (PEP) as reducing and stabilizing agents. The formation of MNPs was optimized reaction conditions to obtain the best colloidal solutions. The characterizations of the biosynthesized MNPs were performed by analysis techniques such as Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED). The TEM data confirmed PEP-AgNPs and PEP-AuNPs in the spherical shape with mean size of 25 nm and 7 nm, respectively. The XRD and SAED patterns showed the synthesized nanoparticles existing in crystalline nature. Antibacterial and catalytic activities have been investigated for their applications. The PEP-AgNPs exhibited a strong antibacterial activity against three strains including Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The excellently catalytic activity of both the biosynthesized nanoparticles has been demonstrated for reduction of nitrophenols and degradation of toxic organic dyes via study on their kinetics.

Photocatalytic degradation of malachite green using titanium dioxide immobilised on oil palm empty fruit bunch derived cellulose

Titanium dioxide (TiO2), cellulose and TiO2 immobilised on cellulose at 10–70 wt% were synthesised through hydrothermal method. These samples were characterised by using X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX) and Fourier transmission infra-red spectroscopy (FTIR). The TiO2 produced was in an amorphous phase. TiO2 particles were spherical and composed of titanium (Ti) and oxygen (O) elements only. TiO2 showed O-Ti-O bonds due to the presence of TiO2 precursor. Cellulose possesses peak at 2894 cm−1 due to the vibration of the carbon (C) – hydrogen (H) bond. The effect of various parameters such as amount of TiO2 immobilised on cellulose (10–70 wt%), catalyst concentration (0.3 g/L to 1.1 g/L), dye concentration (20 ppm to 100 ppm), solution pH (pH 1 to 9) and solution temperature (27 °C to 65 °C) for photocatalytic degradation were studied in order to determine the optimum conditions. It was found that the highest photocatalytic degradation efficiency of malachite green (78.27%) after 1 h was achieved in the presence of 50 wt% TiO2 immobilised on cellulose (50 T/C) at the optimum conditions with the catalyst concentration of 0.9 g/L, initial dye concentration of 20 ppm, natural solution pH 5 and solution temperature of 27 °C. In addition, 100% chemical oxygen demand (COD) removal was achieved at the prescribed optimum condition. In the reusability study, it was found that the reused 50 T/C which regenerated through washing by distilled water and 0.1 M of sodium hydroxide maintained high photocatalytic activity (78%) after three catalytic cycles. This study proved that appropriate amount of TiO2 immobilised on cellulose potentially to be used as an effective and efficient photocatalyst to degrade the organic dye in water.

Thermal behavior of Cu-doped TiO2 gels synthesized by the sol-gel method

The thermal behavior of Cu-doped TiO2 gels obtained by the sol-gel method was investigated by thermogravimetric and differential thermal analysis (TG/DTG/DTA) and differential scanning calorimetry (DSC) measurements. The comparative investigation of the structure and morphology of the as-prepared gels and of the nanopowders obtained by annealing them was realized by transmission electron microscopy (TEM), Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Significant differences were noticed depending on the amount of dopant (0.5 or 2.0 mol % CuO). A higher dopant concentration resulted in a more complex decomposition of the sample. This behavior was associated with the formation of various molecular species in the sol-gel solutions before gelation, determined by the different amount of the dopant used.

STRUCTURAL, MORPHOLOGICAL STUDY OF NEODYMIUM SUBSTITUTED COBALT ZINC FERRITES NANOPARTICLES SYNTHESIZED VIA CO-PRECIPITATION METHOD

Neodymium (Nd) doped cobalt, zincferrite nanoparticles, i.e; Co0.5Zn0.5Fe2-xNdxO4, were synthesized using co-precipitation method. The compositional characterization was done by Fourier transmission infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and XRD. To understand the structural and magnetic properties of cation dispersal has been proposed and found to be in agreement with experimental observations. The XRD analysis confirmed that the prepared material is single phase spinel cubic. XRD analysis gave average crystallite size in the range 29.9-31.4 nm. There was a slight increase in crystallite size with the Neodymium substitution. The average value of lattice parameter came as 8.095-8.26 Å. The absorption bands observed through FTIR analysis were in the expected range for the single phase spinel cubic. SEM analysis showed that the irregular grains were formed in the micrometer range.