Fourier Transform Infrared Spectroscopy Peak Research Articles

Impact of rare-earth ions on the physical properties of hexaferrites Ba0.5Sr0.5RE0.6Fe11.4O19, (RE = La, Yb, Sm, Gd, Er, Eu, and Dy)

Rare-earth ions RE3+ doped Sr/Ba-hexaferrite nanoparticles were prepared via the sol-gel auto-combustion method. The effect of replacing Fe3+ by RE3+ ions on the structural and morphological properties have been investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The functional groups were detected by Fourier Transform infrared spectroscopy (FTIR). Hysteresis loops were formed by applying a magnetic field of ± 20 kOe, using vibrating sample magnetometer (VSM). The electric and dielectric parameters; conductivity (σ), dielectric constant (ε′), dielectric loss (ε"), tangent loss (tan δ) were obtained using LCR Meter at frequencies up to 5 MHz and temperature up to 620 K. The XRD analysis showed a pure M-type hexagonal phase with a space group P63/mmc. The Bragg's angle 2θ has been shifted toward lower values by RE3+ addition. Sedimentation of RE3+ ions on the grain boundaries makes barriers for the grain growth, where the size of nanoparticles varies in the range (35.22−51.9 nm). The characteristic FTIR peaks of hexaferrites are obtained between 430 and 595 cm−1. The hexagonal shape shown in the (SEM) images reflects the quality of preparation and uniform distribution of RE3+ ions. (EDX) results showed that there is no significant difference between the theoretical and experimental data for the weight percent of each element. The hysteresis loops give rise to the ferromagnetic nature of the materials at 300 K. Substitution of RE3+ ions with different properties changes the hopping rate of electrons between cations of the same element, which affect the dielectric parameters.

Geographical variations and correlation among some chemical and thermal properties of Almaciga (Agathis philippinensis Warb.) resins from selected commercial sites in the Philippines

Almaciga (Agathis philippinensis Warb.), a tropical conifer that is tapped for its resin commercially known as Manila copal, grows in many parts of the Philippines, but resin buyers prefer and pay a better price for resin from southern Palawan. The study was done to characterize almaciga resins obtained from commercial sites in Davao Oriental and Palawan (Brooke's Point and Marufinas) to explain the quality and price differences. Fresh and aged resin samples were subjected to wet chemical, thermal, and spectral analyses. Generally, the resin samples were found to be soluble in the more polar solvents although significant variations were observed for resins from various sites. Titrimetric determination revealed no significant variation in acid and saponification values, although the Brooke's Point resin had significantly lower unsaponifiable components. Predominant Fourier transform infrared spectroscopy (FTIR) absorption peaks for fresh resin include strong C=O stretch and weak = C–H stretch. Aged Palawan resins, which showed increased solubility in polar solvents, exhibited increased intensity of prominent FTIR peaks such as O–H stretch and C=O stretch. The weak peak at 1719 cm−1 seen in fresh Palawan resins was no longer observed in aged resins. DSC revealed the semi-crystalline nature of almaciga resin and melting temperatures similar to diterpenoid resin acids. This is attributed to the presence of increasing amounts of oxidized abietic acids as shown by gas chromatography-mass spectrometry (GCMS). For the Davao Oriental resins, significant amount of agatholic acid was shown, while resin acids of the abietane and pimarane type were conspicuously absent in the GC-MS spectrograms. The study found evidence that almaciga resins from Davao and Palawan differ in chemical composition and physical properties, which could explain the quality and price differences.

MICROBIAL ENZYMATIC REDUCTION OF IRON NANOPARTICLES FOR THE CONTROL OF HUMAN PATHOGENS, STAPHYLOCOCCUS AUREUS, AND SALMONELLA TYPHI

Objective: The objective of this study was to synthesis, characterize, and evaluation of antimicrobial potential of iron nanoparticles (Fe NPs) using Serratia marcescens.
 Methods: Fe NPs were fabricated by microbial enzyme using ferric chloride as an agent of reduction and stabilization. Fe NPs formation and their elemental nature were confirmed by ultraviolet (UV)-absorption spectroscopy and energy dispersive X-ray spectroscopy, respectively. The morphology of Fe NPs was characterized by a scanning electron microscope (SEM). Functional groups of biomolecules associated with Fe NPs were inferred from characteristic Fourier transform infrared (FTIR) spectroscopy peaks. The antibacterial activity is determined by the disc diffusion method.
 Results: Synthesized Fe NPs exhibited characteristic UV-absorption spectrum peaks at 263nm. FTIR spectroscopy peaks of Fe NPs, 3411.66, 1629.16, 1039.63, and 601.90 cm−1 corresponds to carbonyl, disulfides, and ethers groups. SEM study demonstrated that the average size was from 200nm with interparticle distances. The crystalline nature of Fe NPs was confirmed from the X-ray diffraction peaks analysis. The intense diffraction peaks due to Fe NPs at 16.32, 22.56, 35.54, 41.08, 52.36, 61.42, 66.42, 78.1, and 85.08. Corresponding to the 110, 150, 200, 430, 550, and 950 facets of the face-centered cubic crystal structure conformed to the Joint Committee on Powder Diffraction Standards: 89-3722 of iron. Antimicrobial activity of Fe NPs against tested Gram-positive and negative bacterial strains showed significant inhibitory zones.
 Conclusion: The inhibitory zones obtained in the present study reveal that the Fe NPs can act as a good antibacterial agent.

Qualitative and Quantitative Analysis of Sorghum Grain Composition Including Protein and Tannins Using ATR-FTIR Spectroscopy

Chemical composition and grain quality traits are important factors related to the end-use quality of sorghum. Thus, rapid and non-destructive analytical methods for screening sorghum for desirable grain quality traits benefit the industries using sorghum for food, feed, and biofuels as well as sorghum breeders and seed companies working to improve the grain quality of sorghum. In the present study, a method based on Fourier-transform infrared spectroscopy (FTIR) was developed to characterize the major chemical components in sorghum flour. Sorghum flour had three major FTIR active regions from 1800 to 800 cm−1. As expected, FTIR spectra revealed that starch was the primary compound in sorghum flour, followed by protein with only minor amounts of lipids and phenolic acids. Phenolic acids were characterized by a peak at 1709 cm−1, which varied in intensity across sorghum varieties. Tannin sorghum could be discriminated from non-tannin sorghum by a shift in O–H stretch band around 3300 cm−1 and their C=C absorption peaks at 1608 and 1522 cm−1. Flour from the outer part of the kernel (corneous endosperm) had greater protein and lipid absorbance while the inner kernel (floury endosperm) had stronger starch absorbance. Pearson’s correlation analyses between FTIR peak intensities and protein/starch content showed that starch content did not have a significant correlation with infrared peaks, whereas the amide I peak at 1652 cm−1 (C=O stretching group), highly correlated with protein content (P ≤ 0.05). A calibration curve (Y = 127.79X-14.345, R2 = 0.9454) was built using peak height at 1652 cm−1 to predict protein content and this was applied to determining protein digestibility.

Green synthesis of silver nanoparticles and its potential effect on phytopathogens

Nanotechnology provides environmentally friendly green technique for synthesizing silver nanoparticles using various parts of the plant. Here we used aqueous leaf extract of Symplocos racemosa for synthesis of silver nanoparticles (AgNPs) by adding 1 mM AgNO3 as reducing agent. Silver nanoparticles (AgNPs) from aqueous leaf extract and 1 mM AgNO3 are successfully synthesized here. The characterization of the silver nanoparticles were carried out by UV–visible spectroscopy, XRD (X-Ray Diffraction), FTIR (Fourier Transform Infrared Spectroscopy) and Transmission Electron Microscopy (TEM), FE-SEM (Field Emission Scanning Electron Microscope), EDX (Energy Dispersive X Ray Spectroscopy) and Transmission Electron Microscopy (TEM). The limit of UV–visible spectroscopy at 422 nm supported the reduction AgNO3 to AgNPs. FTIR peaks were observed in the frequencies near 3270, 1640, 1408, 1080 cm−1 implying that O–H stretch, C–C, –CH3, and C–O–C groups respectively from the extracts, which were capped with silver nanoparticles (AgNPs). Antimicrobial activity of synthesized silver nanoparticles have been studied on Pseudomonas aeruginosa.

ION BEAM IRRADIATION EFFECTS ON SURFACE MORPHOLOGY AND OPTICAL PROPERTIES OF ZnO/PVA COMPOSITES

Polymer nanocomposites composed of zinc oxide nanoparticles (ZnO NPs)-doped polyvinyl alcohol (PVA) polymer matrix have been synthesized using solvent casting preparation method. The ZnO/PVA polymer nanocomposite films are irradiated with different argon ion beam fluences using broad-beam ion source. The prepared films are characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and UV–visible spectroscopy. The XRD shows that ZnO NPs are successfully formed on PVA polymer and the mean size of ZnO NPs is 31.2[Formula: see text]nm. The FTIR peaks indicate that ZnO NPs are attached to the polymer chains, whereas the SEM analysis shows that ZnO NPs are homogeneously dispersed into the PVA polymer surface. The optical bandgap, band tail width and number of carbon atoms in cluster are obtained and discussed using UV–visible spectroscopy. The transmittance is shown with low transmittance intensity in the UV region with the addition of ZnO NPs and ion beam irradiation. The optical bandgap [Formula: see text] showed significant decrease from 5.25[Formula: see text]eV for pristine PVA to 3.10[Formula: see text]eV by adding ZnO and from 3.10[Formula: see text]eV for un-irradiated ZnO/PVA to 2.98[Formula: see text]eV after being irradiated by [Formula: see text][Formula: see text]cm[Formula: see text]. The number of carbon atoms in cluster [Formula: see text] is increased by ZnO addition, whereas the Urbach energy [Formula: see text] is decreased. These results confirmed that there are significant modifications in PVA polymer, and the produced flexible ZnO/PVA is a good polymer nanocomposite film for technological applications.

Phytosynthesis of cerium oxide nanoparticles and investigation of their photocatalytic potential for degradation of phenol under visible light

Nowadays, synthesis of cerium oxide nanoparticles (CeO2-NPs) via employing plants as reducing and stabilizing agents has been widely dealt by research community owing to their eco-friendly, simple, cost effective and renewability features. In the same line of action, current study has first time reported the formation of Elaeis guineensis leaves mediated CeO2-NPs. The phytochemicals corresponding to O–H, CO and N–H functional groups displayed their major contribution as reducing and stabilizing agents in the formation of CeO2-NPs, revealed through Fourier transform infrared spectroscopy (FTIR). The formation of uniform agglomerated cubic structured CeO2-NPs containing particle size range 13–16 nm was confirmed through observing FTIR peak at 560 cm−1, FESEM and EDAX results. The XPS and XRD revealed the chemical oxidation states of Ce3d and formation of cubic structured cerium oxide particles containing crystal size 5.2 nm. An excellent photocatalytic degradation potential was exhibited by biofabricated CeO2-NPs through demonstrating 92.24% removal efficiency in 360 min irradiation time under visible light. The kinetic modelling of CeO2-NPs for photocatalytic degradation of phenol was found to be followed by Langmuir Hinshelwood (L-H) model. Moreover, a photocatalytic degradation mechanism was also predicted to explain the removal phenomenon of phenol by employing CeO2-NPs photocatalyst. The experimental results concluded that Elaeis guineensis leaves can be employed as an inexpensive and nonhazardous potential bioresource for the synthesis of other metal oxide nanoparticles, which may have their applications in medical and environmental field.

Structural Characterization of Controlled Decrystallization of Cassava Starch

AbstractNative starch granule has a complex crystalline structure. Controlled decrystallization cassava starch (CDCS) was prepared by the alcohol–alkali method. Polarized microscopy, scanning electron microscopy (SEM), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis of the CDCS are carried out to investigate its structural information. The results show that the relative crystallinity (RC) of the processed cassava starches can be reduced from 25.56% to 17.90% by adjusting the concentration of sodium hydroxide while keeping the integrity of the starch granule. During the decrystallization process, as the sodium hydroxide concentration is increased from 0.25 to 1.25 mol L−1, the polarized light of the starch granules disappear from the inside to the outside, and the X‐ray diffraction peaks of native cassava starch (NCS) disappear sequentially from 17.16°, 23.04°, 15.08°, to 17.83°. On the other hand, the FTIR peaks of the NCS centered at 1645 cm−1 is shifted to about 1600 cm−1, and the intensity of the peaks at 3424, 2929, 1645, and 1017 cm−1 become weaker with decrystallization process. This study provides valuable data and a theoretical basis to understand the mechanism of the controlled decrystallization of cassava starch.

Direct preparation of β-crystalline poly(vinylidene fluoride) nanofibers by electrospinning and the use of non-polar silver nanoparticles coated poly(vinylidene fluoride) nanofibers as electrodes for piezoelectric sensor

A 96% β-crystalline poly(vinylidene fluoride) nanofibers (PVDF NFs) were prepared by collecting electrospun NFs on a roller operated at 5000 rpm, followed by annealing at 150 °C. Dodecylamine functionalized non-polar silver nanoparticles (Ag NPs) were synthesized. The Ag NPs were brush coated on a PVDF NFs support and used as an electrode to demonstrate a piezoelectric sensor (PS). PVDF NFs was characterized with Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and field emission-scanning electron microscopy (FE-SEM). Changes in the absorbance of FTIR peak, 1275 cm−1, revealed that the rise in roller speed from 0 to 5000 rpm, increased the β-phase composition from 64 to 92% (rest was γ-phase), decreased the lowest observed NFs diameter from 399 to 260 nm, and increased the orientation of NFs along the direction of rotation. The peaks relevant to β-phase found in XRD patterns (20.8°) and DSC thermograms (166 °C) were confirmed these findings. Annealing of NFs prepared at 5000 rpm (R5000) at 150 °C, increased the degree of crystallinity from 54.7 to 58.3% and the % of β-phase from 92 to 96%, highest among all samples. The electrode was characterized using FE-SEM and energy dispersive X-ray spectroscopy (EDXS), which confirmed the Ag NPs coating (35–184 nm diameter). The static and dynamic load analyses were suggested that PS made using R5000 annealed at 150 °C was capable of sensing 0.3–500 N force. The voltage generated (400 mV) upon applying load on PS with a fingertip (~3 N) can charge a 1 μF capacitor in 0.8 s and also upon 10 × amplification a 4 V light emitting diode turned on to glow. Overall, the PS made with β-crystalline R5000/150 and non-polar Ag NPs coated electrodes was found to be useful for force sensing and energy harvesting.

Biosynthesis of silver, gold and silver–gold alloy nanoparticles using Persea americana fruit peel aqueous extract for their biomedical properties

While several green biomolecules have been used to synthesize functional and biologically compatible nanoparticles, little attention has been paid to Persea americana (PA) (avocado) fruit extract as a potential reducing agent. This study used avocado fruit peel aqueous extracts to synthesize silver nanoparticles (PAAgNPs), gold nanoparticles (PAAuNPs) and bimetallic alloy nanoparticles (PAAg–AuNPs). The particles were characterized using UV–vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy, selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy and X-ray diffraction among others. The particles were assessed for their antibacterial, antifungal and antioxidant properties. The UV–vis spectroscopy showed PAgNPs, PAAuNPs and PAAg–AuNPs with surface plasmon resonance at 455.5, 538 and 540.5 nm, respectively. The significant FTIR peaks: PAAgNPs (3358 cm−1), PAAuNPs (3503 cm−1) and PAAg–AuNPs (3651 cm−1) pointed to protein as both capping and stabilizing agents for the synthesized nanoparticles. Generally, the particles were spherical, with size range of 18–80 nm for PAAgNPs, 16–71 nm for PAAuNPs and 44–55 nm for PAAg–AuNPs. The energy-dispersive X-ray spectra showed silver, gold and silver/gold as conspicuous metals in PAAgNPs, PAAuNPs and PAAg–AuNPs colloids, respectively. SAED showed ring-shaped patterns for the particles. The nanoparticles effectively inhibited growth of tested bacteria (11–94%) for PAAgNPs, (10–77%) for PAAuNPs and (20–85%) for PAAg–AuNPs. The effectiveness of the biosynthesized nanoparticles can be placed as PAAg–AuNPs > PAAgNPs > PAAuNPs. The fungal inhibition performances are 33–76%, 50–82% and 27–88% for PAAgNPs, PAAuNPs and PAAg–AuNPs, respectively, while DPPH-scavenging activities were 57.82–63.25%, 15.28–54.50% and 53.05–54.26%, which were dose dependent at the tested concentrations of 20–100 µg/ml with good antioxidant activities compared to standard BHA (41.46–84.57%) and ascorbic acid (43.56–91.10%). The bleaching inhibition assay of ABTS showed activities of 56.15–85.43% (PAAgNPs), 34.67–50.93% (PAAuNPs) and 45.31–94.01% (PAAg–AuNPs). The lower concentrations of EC50 were obtained in nanoparticles (24.45–58.33 µg/ml) compared with the standards (38.42–69.04 µg/ml), indicating that the nanoparticles could suffice as good agents in drug consignment. This study has demonstrated the potential of P. americana fruit peel aqueous extracts to synthesize AgNPs, AuNPs and Ag–AuNPs for antimicrobial and antioxidant applications. The current work, to the best of our knowledge, is the first to use avocado peel extract to synthesis nanoparticles.

Characterization of Zinc oxide Nanostructures prepared by hydrothermal method with Antibacterial property

In this study, Zinc oxide nanostructures were synthesized via a hydrothermal method by using zinc nitrate hexahydrate and sodium hydroxide as a precursor. Three different annealing temperatures were used to study their effect on ZnO NSs properties. The synthesized nanostructure was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Atomic force microscope (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). Their optical properties were studied by using UV -visible spectroscopy. The XRD analysis confirms that all ZnO nanostructures have the hexagonal wurtzite structure with average crystallite size within the range of (30.59 - 34.52) nm. The crystallite size increased due to the incensement of annealing temperature. FESEM analysis indicates that ZnO has hexagonal shape of cylindrical pores, plate-like nanocrystals and Nanorods. AFM analysis shows that the average surface roughness of ZnO Nanostructures increases from 3.96 to 19.1 nm with the increase of annealing temperature. The FTIR peaks indicate successful preparation of ZnO Nanostructures. The FTIR method was used to analyses the chemical bonds which conformed the present of the Zn-O group in the region between (400-500) cm-1. The UV-visible showed a red shift in the absorption spectra related to the shift in the energy gap related to increase in the particle size. the band gap energy has been calculated from the optical absorption spectra. The annealing process has been fond more effective on the value of energy gap. As the annealing temperature increases, the value of energy gap, increases as well; from (3.12to 3.22) eV. The prepared Nanostructure is used for antibacterial property. It shows strong antibacterial activity against S. aureus and P.aeuruginosa bacteria by the agar disc diffusion method. The white precipitate of ZnO NSs has superior antibacterial activity on gram-positive (S. aureus) than the gram-negative (P.aeuruginosa) bacteria.

Synthesis of Nanofibrillated Cellulose by Combined Ammonium Persulphate Treatment with Ultrasound and Mechanical Processing

Ammonium persulfate has been known as an agent for obtaining nanocellulose in recent years, however most research has focused on producing cellulose nanocrystals. A lack of research about combined ammonium persulfate oxidation and common mechanical treatment in order to obtain cellulose nanofibrils has been identified. The objective of this research was to obtain and investigate carboxylated cellulose nanofibrils produced by ammonium persulfate oxidation combined with ultrasonic and mechanical treatment. Light microscopy, atomic force microscopy (AFM), powder X-Ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and Zeta potential measurements were applied during this research. The carboxylated cellulose suspension of different fractions including nanofibrils, microfibrils and bundles were produced from bleached birch Kraft pulp fibers using chemical pretreatment with ammonium persulfate solution and further defibrillation using consequent mechanical treatment in a high shear laboratory mixer and ultrasonication. The characteristics of the obtained nanofibrils were: diameter 20–300 nm, crystallinity index 74.3%, Zeta potential −26.9 ± 1.8 mV, clear FTIR peak at 1740 cm−1 indicating the C=O stretching vibrations, and lower thermostability in comparison to the Kraft pulp was observed. The proposed method can be used to produce cellulose nanofibrils with defined crystallinity.

Determination of phase specific localization of carbon black in ternary rubber blends: A macroscopic approach by fourier transform infrared spectroscopy (FTIR)

The phase specific localization of the reinforcing fillers like carbon black (CB), which has been known to influence the physical and mechanical performance of the rubber blends, can be determined by different characterization techniques, however, only for binary rubber blends. They have been failed so far when applied for more complicated systems like filled ternary rubber blends. In the present work we introduced a new technique using the attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) with germanium crystal for characterization of the specific localization of CB in a ternary blend of solution styrene butadiene rubber (SBR), butadiene rubber (BR) and natural rubber (NR). It is the first time we could follow the change of the amount of CB localized in each phase of this blend along the mixing time. CB firstly is incorporated into the NR phase and then it obviously migrates from the NR phase to the SBR phase as a function of mixing time that corresponds very well with the theoretical prediction based on the Z-model using the surface tension values of the filler and rubber blend components. The interaction between CB and rubber components can be qualitatively proved by the shift of the FTIR peak. Thermogravimetric analysis (TGA) was used to support the results obtained by the FTIR method. The study was further extended to follow the CB distribution in multi-step mixing.

Development of rapid method to assess microbial quality of minimally processed pomegranate arils using FTIR

Fourier transform infrared spectroscopy (FTIR) spectra were correlated with microbial quality of minimally processed pomegranate (Punica granatum) arils stored at 10 °C using chemometrics. FTIR data processed in three ways i.e. FTIR spectrum, first derivative for FTIR spectrum and peak integrated data of FTIR spectrum was used as independent variables for preparing regression models by partial Least Square Regression (PLS-R) and artificial neural networks (ANN) for predicting the total viable count (TVC) and yeast and mold count (Y&M). Models built with both ANN and PLS-R using FTIR data demonstrated a high correlation value of R2 > 0.85. Analysis of PLS-R results suggested the production of alcohols and acids with utilization of sugars during storage. This is a first report demonstrating use of FTIR as a nondestructive rapid method for microbial quality analysis of minimally processed fruits.

Comparative FTIR, Compaction and In vitro Dissolution Studies of Plectranthus esculentus Modified Starches in Metronidazole Tablet Formulations by Direct Compression

Wet and dry granulation methods for tablet manufacturing tend to be problematic for thermolabile and moisture sensitive drugs, and few excipients are available for use in direct compression (DC) due to stringent requirements. This study aimed to evaluate the drug/excipients compatibility, compaction and in vitro dissolution properties of Plectranthus esculentus modified starches in tablets using metronidazole as a model drug by DC. Native starch extracted from P. esculentus was modified by three methods and we produced three modified starches namely; acid hydrolyzed P. esculentus starch (APS), pregelatinized P. esculentus starch (PPS), and ethanol dehydrated pregelatinized P. esculentus starch (PPE). For drug/excipient compatibility studies, Fourier Transform Infrared Spectroscopy (FTIR) was used. Powder compaction was evaluated using Heckel model, while in vitro dissolution studies were conducted using USP basket method. The starches were evaluated in comparison with microcrystalline cellulose (MCC PH 101). The FTIR peaks revealed no interaction of these excipients with the drug. Compaction studies indicate that the modifications yielded starches of comparable compact behaviors with MCC PH 101 especially APS and PPE, they both plastically deformed with PPE producing the hardest tablets. APS and PPS disintegrate faster 2.83 and 1.42 min respectively which were significantly different from the disintegration time of MCC PH 101 and PPE which are higher 35.34 and 45.53 min respectively. For the in vitro dissolution, APS and PPS, their T50 and T90 were achieved in less than 10 min, T50 and T90 for PPE were achieved at 38 and 58 min respectively, while for MCC PH 101 both T50 and T90 were not observed after 60 min. APS produced metronidazole tablets of better quality in terms crushing strength, friability and drug-release profile. Acid hydrolysis of P. esculentus starch produced good directly compressible excipient that can be use in DC for immediate release tablet formulations.

Polymethacrylate Coated Electrospun PHB Fibers as a Functionalized Platform for Bio-Diagnostics: Confirmation Analysis on the Presence of Immobilized IgG Antibodies against Dengue Virus.

In this article, a combination of far field electrospinning (FFES) and free-radical polymerization has been used to create a unique platform for protein immobilization via the physical attachment of biomolecules to the surface of the fiber mats. The large specific surface area of the fibers with its tailored chemistry provides a desirable platform for effective analyte-surface interaction. The detailed analysis of protein immobilization on a newly developed bio-receptive surface plays a vital role to gauge its advantages in bio-diagnostic applications. We relied on scanning electron microscopy (SEM), diameter range analysis, and X-ray photoelectron spectroscopy (XPS), along with thermal gravimetric analysis (TGA), water-in-air contact angle analysis (WCA), Fourier transform infrared spectroscopy (FTIR), and atomic force microscopy (AFM) to study our developed platforms and to provide valuable information regarding the presence of biomolecular entities on the surface. Detailed analyses of the fiber mats before and after antibody immobilization have shown obvious changes on the surface of the bioreceptive surface including: (i) an additional peak corresponding to the presence of an antibody in TGA analysis; (ii) extra FTIR peaks corresponding to the presence of antibodies on the coated fiber platforms; and (iii) a clear alteration in surface roughness recorded by AFM analysis. Confirmation analyses on protein immobilization are of great importance as they underlay substantial grounds for various biosensing applications.

Annealing led conversion from polypyrrole to carbon nitride nanowires and the fabrication of highly efficient ammonia sensing device

In this work, first of all, polypyrrole (PPy) nanowires have been successfully prepared using template synthesis technique at room temperature by chemical polymerisation of pyrrole within the pores of anodic alumina template. Secondly, the effect of 4 h annealing on morphological, optical and ammonia gas sensing device properties has been studied at 200 °C and 300 °C. The characterization of unanealed and annealed samples was done by using scanning electron microscopy (SEM), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and time resolved photoluminescence. IV measurements are done for studying gas sensing device. The SEM confirms the flexible wire-like morphology of unannealed and annealed nanowires whereas XRD investigation shows the amorphous nature of unannealed and annealed nanowires. Characteristic peaks of FTIR confirm the formation of PPy nanowires synthesized at room temperature and transition from polypyrrole to carbon nitride nanowires after annealing PPy nanowires at 200 and 300 °C. The transition from PPy to CNx nanowires after annealing is proved by the characteristic FTIR peaks corresponding to C=C and C=N bond and the time resolved photoluminescence spectra recorded at different wavelengths corresponding to polypyrrole and carbon nitride well known transitions. I–V studies of nanowires show the increase in sensitivity of annealed nanowires towards NH3 at about thousand times than that of unannealed nanowires.

Enterococcus species for the one-pot biofabrication of gold nanoparticles: Characterization and nanobiotechnological applications

In the current work, cell-free extracts of four strains of non-pathogenic Enterococcus species of food origin, were studied for the green synthesis of gold nanoparticles (AuNPs), and characterized by UV–Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The AuNPs were evaluated for their Anopheles gambiae larvicidal, dye degradation, antioxidant and thrombolytic activities. The blue-black colloidal AuNPs which absorbed maximally at 549–552nm were nearly spherical in shape, and crystalline in nature with size of 8–50nm. The EDX spectra showed formation of AuNPs to the tune of 89–94%. The prominent FTIR peaks obtained at 3251–3410, 2088 and 1641–1643cm−1 alluded to the fact that proteins were involved in the biofabrication and capping of AuNPs. AuNPs degraded methylene blue and malachite green by 24.3–57.6%, and 88.85–97.36% respectively in 24h, whereas at 12h, larvicidal activities with LC50 of 21.28–42.33μg/ml were obtained. DPPH scavenging activities of 33.24–51.47% were obtained for the biosynthesized AuNPs. The AuNPs prevented coagulation of blood and also achieved 9.4–94.6% lysis of blood clot showing potential nanomedical applications. This study has presented an eco-friendly and economical synthesis of AuNPs by non-pathogenic strains of Enterococcus species for various nanobiotechnological applications.

Magnetic substrate supported ZnO-CuO nanocomposite as reusable photo catalyst for the degradation of organic dye

Magnetic substrate supported heterogeneous nanocatalysts are emerging materials in the field of catalysis. In the present study, magnetic iron oxide supported zinc oxide – copper oxide nanoparticles were synthesised, characterised and evaluated for their photo catalytic activity. Iron oxide nanoparticles were synthesised by simple chemical co-precipitation method and coated with silica by conventional Stober’s method then the surface was decorated with with ZnO-CuO nanocomposite. The obtained nanocomposite was characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy(FTIR), Scanning Electron Microscopy (SEM) and Energy-Dispersive Spectra (EDS). The XRD results confirmed the spinal crystal structure of Fe3O4 and well matches with the peaks of ZnO and CuO. FTIR peak at 1090 cm-1confirmed the presence of Si and peaks below 1000 cm-1 confirmed the presence of metals like Fe, Zn and Cu. SEM results confirmed the spherical and cubic mixed morphology of the nanocomposite. EDAX confirmed the presence of all the elements with high purity. Photocatalytic activity of the nanocomposite was evaluated for degradation of Indigo carmine(IC) dye under UV-visible light irradiation. Indigo Carmine dye was degraded within 2 hrs. The catalyst was easily recovered by applying external magnetic and reused couple of times.

Effect of GGBS and curing temperature on microstructure characteristics of lightweight geopolymer concrete

Cement replacement by supplementary cementitious materials has been gaining momentum as a sustainable mechanism to reduce greenhouse gas emissions while also recycling industrial by-products. This paper presents the development and microstructure characterization of fly ash-based lightweight geopolymer concrete incorporating ground granulated blast furnace slag (GGBS). Concrete samples were prepared with 0%, 25% and 50% GGBS replacement and cured at 30°C, 60°C, and ambient temperature. While dune sand and lightweight expanded clay were used as aggregates, a mixture of sodium silicate and sodium hydroxide served as the alkaline activation solution. Microstructure evaluation was carried out at 7 and 28 days employing scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Residual fly ash and GGBS were identified in the concrete and bonded to geopolymeric reaction products. The microstructure highlighted the formation and coexistence of aluminosilicate hydrate and aluminum-rich calcium silicate hydrate with traces of sodium. Subsequent polymerization was also verified by an increase in FTIR and DSC peaks.