Refractive Index Data Research Articles

Physical properties of La:ZnO thin films prepared at different thicknesses using spray pyrolysis technique

Herein we investigate the impact of film thickness on the physical properties of Lanthanum (La) doped ZnO thin films. The films were fabricated using the spray pyrolysis technique with a consistent La content of 5 weight (wt) % in the initial solution. X-ray diffraction analysis indicated the presence of a hexagonal ZnO phase with preferred orientation along the (002) direction and no other phases were detected. The crystallite sizes were calculated using the Halder-Wagner equation, with a maximum size of 16.1 nm observed for a film thickness of 106 nm. Field-emission scanning electron microscopy (FE-SEM) images revealed the formation of a continuous film with an average grain size that increased as the thickness of the film increased. The grain size ranged from 74.5 to 136 nm as the film thickness varied from 106 to 426 nm. Films with lower thicknesses up to 196 nm exhibited two band gaps at approximately 3.2 and 4 eV, while films with higher thicknesses displayed a single band gap around 3.2 eV. The refractive index dispersion for all films was modeled using the Cauchy model, with parameters showing high dependence on the thickness values.The refractive index at high frequency, as calculated using the Cauchy model, was observed to decrease with increasing film thickness, ranging from 1.87 at 106nm to 1.63 at 426nm. Similar values were obtained by fitting the optical refractive index data with the Wemple-DiDomenico relation. Additionally, the UV sensing performance of the films was evaluated against UV light of a single wavelength (365 nm) at applied voltages of 10, 20, and 30V. The rise and decay times were measured, with the film thickness of 426 nm exhibiting the shortest rise and decay times at a specific applied voltage.

Optical Simulations of Nanotextured All‐Perovskite Tandem Solar Cells

AbstractThis numerical study investigates, how textures at various locations of all‐perovskite tandem solar cells affect their optical performance. For this, hexagonal sinusoidal textures with 750 nm period and aspect ratios (height‐to‐period) of 27% (moderate) and 54% (pronounced) are considered. The optical simulations are performed with the finite element method and an algorithm to correct for the thick glass superstrate. The complex refractive index data of the wide‐bandgap (WBG) and narrow‐bandgap (NBG) perovskites with spectroscopic ellipsometry is determined. Texturing between the glass superstrate and the WBG perovskite top cell has an antireflective effect across the whole wavelength region. In contrast, texturing between the WBG perovskite top cell and the NBG perovskite bottom cell has no additional effect for a moderate texture but leads to light trapping in the NBG perovskite for a pronounced texture. Moderate texturing between the NBG perovskite absorber and the metal back contact leads to light trapping in the NBG perovskite but also excites surface plasmons in the copper back contact. Dielectric interlayers between the NBG perovskite and the metal back contact can reduce the plasmonic absorption losses. Texturing potentially allows to increase the current‐matched short‐circuit current density beyond 17 mA .

In silico full-angle high-dynamic range scattering of microscopic objects exploiting holotomography.

Accurate optical characterization of microscopic objects is crucial in academic research, product development, and clinical diagnosis. We present a method for obtaining full and high-dynamic range, angle-resolved light scattering attributes of microparticles, enabling distinction of variations in both overall morphology and detailed internal structures. This method overcomes previous limitations in observable scattering angles and dynamic range of signals through computationally assisted three-dimensional holotomography. This advancement is significant for particles spanning tens of wavelengths, such as human erythrocytes, which have historically posed measurement challenges due to faint side-scattering signals indicative of their complex interiors. Our technique addresses three key challenges in optical side-scattering analysis: limited observational angular range, reliance on simplified computational models, and low signal-to-noise ratios in both experimental and computational evaluations. We incorporate three-dimensional tomographic complex refractive index data from Fourier-transform light scattering into a tailored finite-difference time-domain simulation space. This approach facilitates precise near-to-far-field transformations. The process yields complete full-angle scattering phase functions, crucial for particles like Plasmodium falciparum-parasitized erythrocytes, predominantly involved in forward scattering. The resultant scattering data exhibit an extreme dynamic range exceeding 100 dB at various incident angles of a He-Ne laser. These findings have the potential to develop point-of-care, cost-effective, and rapid malaria diagnostic tools, inspiring further clinical and research applications in microparticle scattering.

Structural, thermo-mechanical, optical and gamma-ray shielding properties of lead-free BaO–ZnO–B2O3–SiO2 and lead-based PbO–Bi2O3–K2O–SiO2 glasses

Lead-free BaO–ZnO–B2O3–SiO2 glass (BZBS) and lead-based PbO–Bi2O3–K2O–SiO2 glass (LS) were synthesized by melt quench technique. Glass samples were irradiated using 60Co gamma source up to 50 kGy dose to study the changes in structural, thermo-mechanical, optical and gamma ray shielding properties. Measured density values of both the glasses were greater than 4.0 g/cc. X Ray Diffraction (XRD) studies confirmed amorphous nature of prepared glasses before and after gamma irradiation. The structural changes induced by gamma irradiation were also investigated using Raman, Positron annihilation lifetime spectroscopy (PALS) and Electron Paramagnetic Resonance (EPR) spectroscopy. PALS data revealed increase in free volume/voids after irradiation. Defect studies carried using EPR spectroscopy confirmed formation of electron trap centre in BZBS glass, whereas in LS glass in addition to the electron trap centers, non-bridging oxygen hole centers (NBOHC) and peroxy radical defects were also observed. Investigations on thermo-mechanical properties demonstrated higher glass transition temperature (Tg), hardness and modulus of elasticity values for BZBS glass as compared to the LS glass, which were found to be decreased after irradiation because of radiation induced defects. Visible transparency and band gap for BZBS glass were found to be higher than that in LS glass. After irradiation, colour change, reduction in transparency as well as band gap, and red shift in absorption edge were observed due to the formation of defects in both the glasses. The values of radiation induced absorption (α) at three different visible wavelengths have been determined for 50 kGy dose using UV–Vis transmission data. Analysis of refractive index data showed around 12 % reflection losses for both the glasses. Annealing of irradiated samples using UV light source showed significant improvement in transparency. Linear attenuation coefficient (LAC) was calculated using XCOM program and experimentally measured using 60Co 1.33 MeV gamma ray. Linear attenuation coefficient of BZBS glass was around 0.20 cm−1 whereas for LS glass value was 0.24 cm−1. Half value layer thickness of prepared glasses was also compared with available standard materials and it was found that prepared glasses may be suitable for shielding of high energy gamma rays.

Improved Temperature‐Dependent Ice Refractive Index Compilation in the Far‐Infrared Spectrum

AbstractA new ice refractive index compilation is reported for a broad spectrum ranging from 0.0443 to 106 μm, focusing on the pronounced temperature‐dependence of ice optical properties in the far‐infrared (far‐IR) segment (15–100 μm). A sensitivity study assuming spherical particles shows that selecting ice refractive indices at 12 temperatures and 215 wavelengths in the far‐IR region gives sufficient accuracy in interpolated refractive indices for developing a new ice crystal optical property database. Furthermore, we demonstrate the differences between the bulk single‐scattering properties computed for hexagonal ice particles with this new compilation compared to a previous iteration at three far‐IR wavelengths where substantial differences are noticed between the two ice refractive index compilations. We suggest that our new ice refractive index data set will improve downstream light‐scattering applications for upcoming far‐IR satellite missions and allow robust modeling of outgoing longwave radiation under ice cloud conditions.

A Novel Terahertz Metamaterial Microfluidic Sensing Chip for Ultra-Sensitive Detection.

A terahertz metamaterial microfluidic sensing chip for ultrasensitive detection is proposed to investigate the response of substances to terahertz radiation in liquid environments and enhance the molecular fingerprinting of trace substances. The structure consists of a cover layer, a metal microstructure, a microfluidic channel, a metal reflective layer, and a buffer layer from top to bottom, respectively. The simulation results show that there are three obvious resonance absorption peaks in the range of 1.5-3.0 THz and the absorption intensities are all above 90%. Among them, the absorption intensity at M1 = 1.971 THz is 99.99%, which is close to the perfect absorption, and its refractive index sensitivity and Q-factor are 859 GHz/RIU and 23, respectively, showing excellent sensing characteristics. In addition, impedance matching and equivalent circuit theory are introduced in this paper to further analyze the physical mechanism of the sensor. Finally, we perform numerical simulations using refractive index data of normal and cancer cells, and the results show that the sensor can distinguish different types of cells well. The chip can reduce the sample pretreatment time as well as enhance the interaction between terahertz waves and matter, which can be used for early disease screening and food quality and safety detection in the future.

Comparison and analysis of goodness of fit and fitting formula between milk fat concentration and refractive index

Milk is considered to be one of the most perfect natural foods for human beings. The analysis of effective components and determination of important components in milk is an important practical work. Based on the previous measurement data of fat volume concentration and refractive index of milk in the market, this paper forms a fitting formula through mathematical fitting, which can solve the corresponding relationship between nonmeasurement points of milk concentration and refractive index. Because the actual measurement points are limited, its practical application is not convenient. However, fitting formulas can calculate the corresponding values of infinitely many points, which can be easily applied. However, judging from the goodness of fit of the fitting formula, a theoretically good fitting formula may produce underfitting and overfitting in practical application. Through the analysis of the first-order to sixth-order fitting formulas of milk concentration and refractive index, this paper tells us that the fitting formula with high goodness of fit is not necessarily a good formula. The specific problems should be analyzed in the application process to make the theory more consistent with the actual situation. From the calculation and analysis in this paper, it can be seen that the fitted sixth-order formula has the best effect when the fat volume concentration of milk is 0–10%. When considering a fat volume concentration of 0–34% in milk, the fitted second-order formula performs better.

A Theoretical and Experimental Approach to Ultrasonic Velocities, Densities, and Refractive Indices in Benzene and Aniline Mixture

The study investigates the theoretical velocities of binary liquid mixtures comprising Aniline and Benzene under 2MHz ultrasonic waves at temperatures of 303.15K, 308.15K, and 313.15K, examined in relation to mole fraction. Experimental data is compared with various theoretical models, including Nomoto theory (NOM), Ideal mixing relation (IMR), Impedance Relation (IR), Rao’s Specific Velocity Method (R), and Junjie’s relations (JR). The work reflects the changes in refractive index with varying liquid density across different mole fractions, explaining observed impacts on ultrasonic velocities. To assess the goodness of fit, Chi-square tests and average percentage errors are employed, allowing for an evaluation of the relative applicability of these theories within the studied systems. The study also explores how the thermos-acoustical characteristics of the systems evolve concerning the mole fraction of a common molecule, shedding light on molecular interactions. Furthermore, various parameters for the binary mixture, such as discrepancies in ultrasonic velocity, excess isentropic compressibility, surplus acoustic impedance, excess intermolecular free length, and molar refraction deviation, are computed using experimental data of density, refractive index, and ultrasonic velocities at different mole fractions of benzene in the aniline-benzene mixture. These calculations serve to reflect the intermolecular interactions present in the binary liquid mixture.

Pure TeO2 glass: Influence of synthesis conditions on linear and non-linear optical, magneto-optical and structural properties

The first systematic study of linear and non-linear optical, magneto-optical and structural properties of pure TeO2 glass is presented with regard to different synthesis and material processing conditions. Prepared glasses were synthesized by the intermittent quenching from 900 ∘C in platinum or alumina crucibles and characterized prior to and after optical polishing. The position of the long-wavelength/phonon absorption edge was investigated using various optical models and experimentally obtained data of refractive index and Verdet constants were used for the estimation of magneto-optical anomaly parameter. During synthesis in alumina crucible, up to about 11 wt.% of Al2O3 incorporates into the glass (verified by EDS/XRF and Raman/FTIR spectroscopy) partially transforming the original pure TeO2 glass backbone structure composed of [TeO4] trigonal bipyramids to [TeO3+1] and [TeO3] structural units with the expected integration of Al into Te−O−Al bridges. The presence of Al2O3 results in lowered density ρ (5.60 → 4.72 g cm−3), refractive index n1550 (2.086 → 1.927) and Verdet constant V632 (36.3 → 21.9 rad T−1 m−1) and in increased optical-band-gap energy Eg (3.69 → 3.72 eV) and Abbe number νD (19.9 → 26.9) compared to pure TeO2 glass prepared in platinum crucible. A dataset of the obtained complex optical parameters (refractive index and extinction coefficient) in the wide spectral range of 193 − 11000 nm is included in the supplementary part.

Discrimination of five commercial Guibourtia wood species using terahertz time domain spectroscopy combined with machine learning approaches

Abstract Terahertz waves hold significant potential for applications in wood identification, owing to their good penetration and distinctive fingerprints in wood. This study focuses on wood samples from five different Guibourtia species as the research objects. The terahertz time-domain spectroscopy (THz-TDS) is employed to acquire the spectroscopic signals of the wood samples and to extract their optical parameter data. The THz refractive indices are dimensionally reduced through principal component analysis (PCA), and three machine learning models, namely partial least squares-discriminant analysis (PLS-DA), random forest (RF), and support vector machine (SVM), are employed to classify the wood of five different Guibourtia species. Time delays of the wood samples from five different Guibourtia species are concentrated in the range of 60–62 ps and exhibit different amplitudes in the frequency domain. Refractive indices showed significant variations within the THz band. PCA for dimensionality reduction of terahertz time-domain spectral data significantly improves the recognition rate of machine learning models. Applying PCA to the refractive index data, the RF model achieves a highest recognition rate of 96.9 % and an overall classification accuracy of 98 %. Current results demonstrate that THz-TDS enables rapid, accurate, and non-destructive classification and identification of wood from the Guibourtia species.

Refractive index measurements of liquids from 0.5 to 2 µm using Rayleigh interferometry

There is growing interest in the refractive index of liquids beyond the visible and into the short-wave infrared (SWIR) for applications such as the study of liquid-core fibers and supercontinuum generation. However, most of the data reported are in the visible. For liquids with a wide transmission window in the SWIR region, refractive index data are sparse. We present a Rayleigh interferometry-based refractometer to characterize the refractive index relative to standard materials at seven different wavelengths (543.4, 632.8, 780, 973, 1064, 1550, and 1970 nm) at a temperature of ~ 21.3 ± 0.6 °C. We also show Sellmeier fits using our results juxtaposed with previously published data. Our data extends previous work to the SWIR.

Abstract 2530: Advancing ICK assay: Real-time, label-free imaging of lymphocyte subsets

Abstract Background: Immune Cell Killing (ICK) Assay is pivotal in immunology and clinical research, uncovering the intricate connections between the immune system and diseases. Traditional ICK assays utilizing antibody staining for endpoint data generation pose challenges in capturing dynamic interactions. Moreover, antibody labeling for data quantification may compromise sensitivity, especially with low-affinity antibodies or a limited number of cells. The anticipation of label-free lymphocyte subset classification and real-time effector/target cell interaction analysis in one field of view is expected to provide more valuable insights than traditional ICK assays. Previous studies achieved 70-80% accuracy in image-based lymphocyte subset classification using digital holographic microscopy, light scattering, etc. but the cells’ condition during the cell sorting or sample preparation process may affect the lymphocyte subset status, resulting in real morphological discrepancies. Our approach focuses on directly sorting human PBMCs to enable label-free, dynamic interaction analysis of natural immune system responses in one field of view. Method: In this study, PBMC samples from 6 individuals were separated using standard-density gradient centrifugation and labeled with antibodies. Data were acquired using the Holotomographic Microscope HT-X1 (Tomocube Inc.). We employed Densenet 121 as the deep learning model architecture, considering the trade-off between memory consumption and performance. The cross-entropy loss function was utilized, and the AdamW optimizer was chosen for model parameter optimization. Input data consisted of 3D refractive index (RI) data for individual cells, each of sized (20, 54, 54). Individual cell labeling was performed using staining information. Results: An overall accuracy of 93.75% in Human PBMC subtype cell classification was achieved. In stage 1, an accuracy of 97.56% was demonstrated in classifying [CD14, CD15, Others]. Among the cells classified as "Others" in stage 2, [CD3, CD19, CD16&CD56] displayed an accuracy of 93.5%. In stage 3, classifying [CD4, CD8] within the CD3 subtype achieved an accuracy of 90.2%. This classification is presumably based on pattern recognition of the chromosomal landscape in holotomography images. Conclusion: Our research has successfully demonstrated the feasibility of real-time label-free lymphocyte subset classification. This approach enabled the classification of effector cells as live cells in ICK assay and the analysis of effector-target cell dynamic interactions. Further training in the classification of more detailed subtype cells and various cell death types will provide additional insights. The advancement of this technology is expected to play a pivotal role in disease prevention, treatment, vaccine development, medical research, and academic studies. Citation Format: Sanggeun Oh, Jaephil Do, Hyun-Seok Min, Dongmin Ryu, Wei sun Park. Advancing ICK assay: Real-time, label-free imaging of lymphocyte subsets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2530.

Real-time simultaneous refractive index and thickness mapping of sub-cellular biology at the diffraction limit

Mapping the cellular refractive index (RI) is a central task for research involving the composition of microorganisms and the development of models providing automated medical screenings with accuracy beyond 95%. These models require significantly enhancing the state-of-the-art RI mapping capabilities to provide large amounts of accurate RI data at high throughput. Here, we present a machine-learning-based technique that obtains a biological specimen’s real-time RI and thickness maps from a single image acquired with a conventional color camera. This technology leverages a suitably engineered nanostructured membrane that stretches a biological analyte over its surface and absorbs transmitted light, generating complex reflection spectra from each sample point. The technique does not need pre-existing sample knowledge. It achieves 10−4 RI sensitivity and sub-nanometer thickness resolution on diffraction-limited spatial areas. We illustrate practical application by performing sub-cellular segmentation of HCT-116 colorectal cancer cells, obtaining complete three-dimensional reconstruction of the cellular regions with a characteristic length of 30 μm. These results can facilitate the development of real-time label-free technologies for biomedical studies on microscopic multicellular dynamics.

Method for bandgap interpolation of perovskite's spectral complex refractive index.

Lead halide perovskites are a promising class of materials for solar cell applications. The perovskite bandgap depends on the material composition and is highly tunable. Opto-electrical device modelling is commonly used to find the optimum perovskite bandgap that maximizes device efficiency or energy yield, either in single junction or multi-junction configuration. The first step in this calculation is the optical modelling of the spectral absorptance. This requires as input the perovskite's complex refractive index N as a function of wavelength λ. The complex refractive index consists of real part n(λ) and imaginary part k(λ). For the most commonly used perovskites, n and k curves are available from spectroscopic ellipsometry measurements, but usually only for a few discrete bandgap energies. For solar cell optimization, these curves are required for a continuous range of bandgap energies. We introduce new methods for generating the n and k curves for an arbitrary bandgap, based on interpolating measured complex refractive index data. First, different dispersion models (Cody-Lorentz, Ullrich-Lorentz and Forouhi-Bloomer) are used to fit the measured data. Then, a linear regression is applied to the fit parameters with respect to the bandgap energy. From the interpolated parameters, the refractive index curve of perovskite with any desired bandgap energy is finally reconstructed. To validate our method, we compare our results with methods from literature and then use it to simulate the absorptance of a single junction perovskite and a perovskite/silicon tandem cell. This shows that our method based on the Forouhi-Bloomer model is more accurate than existing methods in predicting the complex refractive index of perovskite for arbitrary bandgaps.

Principal component analysis of refractive index spaces: From glass properties to residual colour prediction

Traditionally glass dispersion is described by Abbe numbers and partial dispersions, and colour correction is explained and visualized e.g. with Pg,F- and Herzberger diagrams. We have recently developed an alternative approach to colour analysis and colour correction based on principal component analysis of normalized refractive index data. The resulting diagrams can be used not only for glass selection, but also for quantitative prediction of partial refractive powers and residual colour aberrations. The method is intrinsically model-free, robust to the choice of dataset and wavelengths, and transfers easily to any spectral range.

Densities, viscosities, and refractive indices of binary mixtures of tri-n-butyl phosphate with propan-2-ol and butan-2-ol at 303.15, 308.15, 313.15, 318.15, and 323.15 K

Densities, viscosities, and refractive indices of binary liquid mixtures of tri-n-butyl phosphate (TBP) with propan-2-ol and butan-2-ol at different temperatures between 303.15 and 323.15 K at an interval of 5 K and across the entire range of composition were measured. The data were used to calculate derived properties, such as excess molar volumes, excess thermal expansivities, deviations in viscosities, excess free energies of activation for viscous flow, and deviations in refractive index. The variation patterns of these properties concerning composition and temperature for the propan-2-ol + and butan-2-ol + TBP systems were discussed and attributed to probable intermolecular hydrogen bonding and geometric effects. Notably, the influence of hydrogen bonding was substantial, as evidenced by trends in excess molar volumes and deviations in viscosities. Concentration-dependent polynomial equations were used to fit the measured data of density, viscosity, and refractive index, while Redlich-Kister-type equations were applied for the excess properties. The densities and viscosities were correlated using the Jouyban-Acree model. The correlating abilities of various models, such as Grunberg-Nissan, Tamura-Kurata, Heric, Ausländer, McAllister-3, and McAllister-4 body models, were also evaluated using the viscosity data. Additionally, six new pairs of UNIFAC-VISCO group interaction parameters were computed to predict viscosities of TBP in systems involving alkanes, aromatics, and alcohols, extending the application range of the group contribution model.

Pros and Cons of soft contact lens power mapping

Purpose. To provide an overview of currently available meth- ods and instruments for the measurement of soft contact lens power maps, together with their advantages and potential shortcomings. Material and Methods. The three leading measurement prin- ciples of Moiré Fringe, Shack-Hartmann and Phase Shifting Schlieren were identified, and the relevant literature reviewed and technical specifications summarised. To demonstrate some of the potential deficiencies associated with optical power mapping, a series of measurements were conducted on toric, multifocal and extended depth of focus lenses, using one representative instrument. Raw measured data were analysed using various analysis tools and parameters. Results. Power maps and power profiles are presented for the various lens types. Different smoothing filter settings resulted in significantly different power profiles near the optical centre. The ‘Power versus Azimuth’ profiles showed unexpected results. Conclusion. While all three methods are generally reliable and easy to use, there are still some limitations which need to be considered when interpreting the results. In particular, the profile filter settings need to be chosen carefully for multifocal and extended depth of focus lenses. The need for accurate refractive index data for lens material and solution was demonstrated. Keywords Soft contact lenses, power maps, power profiles, Moiré Fringe, Shack-Hartmann, Phase Shifting Schlieren

Cytotoxicity and bioavailability assessment from thiamin-phospholipid complexation loaded Ajwain oil based self nanoemulsifying system

Poor bioavailability (<5%) of thiamin hydrochloride (TH) primarily relates to its impaired permeability across gut mucosa. To modulate its permeability, a dual system based approach consisting of phospholipid complexation embedded into a self nanoemulsifying system was investigated. Thiamin-Phospholipid Complex (TPC) was developed and its Ajwain oil (AJO)-based self nanoemulsifying formulations (SNFs) were evaluated. Formation of TPC complexation was resulted from molecular interactions held between free bases of thiamin and phospholipid (PL). FTIR characterization reveals that the amino group (-NH2) in the free base of thiamin was physically interacted to phosphate linkage in PL. Single endothermic event in TPC & TH, reveals complexation between PL & free bases as interpreted from DSC data. Their corresponding melting point was 127 °C and 258 °C, respectively. Heat of fusion (ΔHf) in TPC was higher than TH or PL. TPC exhibits a poor conductive environment over TH when diluted with ethanol/Tween20 (T2) medium. Lipophilic character of TPC was confirmed from partition coefficient (log P). Exact combination where ternary components produced fully dilutable nanoemulsion system, was identified using ternary diagram drawn between AJO (incorporated with TPC) as oil phase, and Tween20/Polyethylene glycol 600 (PEG600) as Surfactant/co-surfactant (Smix) at ratios 1:1; 1:2 & 2:1. Seven TPC-loaded self nanoemulsifying formulations (SNFs) were designed which, upon subjected to aqueous phase dilution yielded nanoemulsion with droplet size range 95–190 nm with zeta potential −1.78 ± 0.10 mV. Conductivity and Refractive index (RI) data of SNFs were in the range of 98 ± 7.0 to 231 ± 27 μS/cm and 1.458 to 1.463 units, respectively. In vitro TH release from SNF was determined in hydrochloric (HCl) buffer at pH 1.2, and in phosphate buffer solution (PB) at pH 6.8, data interpretation reveals that TPC delayed the release pattern compared to TH and could be attributed to lipophilic behavior of TPC. Intestinal permeability of drug was assessed from optimized SNF (F1) vs. TH across intestinal gut sac model (Apical to basolateral A→B) resulted in a significant difference in permeability coefficient (1.09 × 10−5cm/h). Antioxidant potential of SNF was demonstrated in the DPPH method. MTT assay of TPC formulation conducted on MCF-7 and MDA-MB-231 (Breast cancer) cell lines showed the developed system from AJO possessed cytotoxicity effect. Pharmacokinetic assessment showed that optimized SNFs produced more than four-fold enhancement in bioavailability over control (TH solution) in the Wistar rat model. Meanwhile Area under curve (AUC) data obtained from TPC (in coarse emulsion) vs.TH produced a significant difference (p < 0.001). It can be concluded that developed SNFs via phospholipid complexation produced lipophilic transformation of TH and its SNFs modulated permeability as well as bioavailability enhancement of thiamin.

Influence of ionic size on the optical and thermodynamical properties of chitosan based polymer composites with different ammonium halides

The biopolymer chitosan has been dissolved with 1% of acetic acid and the same has been embedded with different salts of ammonium halides like NH4F, NH4Cl, NH4Br, and NH4I with different concentrations to make the composites. The density, refractive index, and ultrasonic velocity of the said composite materials were measured and the space-filling factor along with polarizability and dielectric constant is obtained from refractive index data. From the refractive index data, the parameters like dielectric constant(ε), polarizability(α), and space-filling factor are calculated and from the ultrasonic velocity, the thermodynamical properties like relaxation strength (r s), acoustic impedance (Z), adiabatic compressibility (βs), intermolecular free length (Lf) and surface tension (σ) were calculated. The ultrasonic velocity of chitosan solution is 1515 ms− 1. The addition of ammonium halides leads to increase in ultrasonic velocity. The intermolecular free length (Lf), adiabatic compressibility (βs), and relaxation strength (r s) are decreasing and all other parameters are increasing with respect to ionic size and concentration of ammonium halides. All the results are analyzed and discussed with respect to the ionic size of the ammonium salts and concentrations.

Electrochemical and optical studies on photoactive BiVO4-TiO2/poly 3,4-ethylenedioxythiophene assemblies in gel electrolyte: Role of inorganic/organic interfaces in surface functionalization

Inorganic/organic interface assemblies were created from poly 3,4-ethylenedioxythio­phene (PEDOT) interfaced with amorphous BiVO4 and with BiVO4-TiO2. Electrochemical cells-based thermoplastic gel electrolytes containing KI/I2 were used to study the photoelectrochemical behavior of the Inorganic/organic interface electrodes. Optical studies show that doping BiVO4 with TiO2 narrowed the optical band gap to allow more absorption in the visible region and increases solar energy conversion. Evidence for both direct and indirect band gaps was observed. Refractive index data indicates that BiVO4 and BiVO4/TiO2 obey the anomalous dispassion multiple-oscillator model. Chronoampero­metry of these assemblies shows the phenomena of dark current, which correlates to the presence of random electron/hole generation in the depletion layer. PEDOT enhances the photoactivity of BiVO4 only. Electrochemical impedance spectroscopy studies indicated that both kinetic and diffusional control at high and low frequencies, respectively. Furthermore, studies show that as frequency increases, the conductivity increases due to dispersion and charge carrier hopping. All photoactivity outcomes were reproducible.