Muthurangam Govt. Arts College

Nonlinear optical heterocyclic—organic single crystals of N-(Naphthalen-5-yl)-N-Phenyl benzamide (NNNPB) was synthesized using N-phenylnaphthalen-1-amine and benzoyl chloride. Single crystals of NNNPB resolved by X-ray diffraction technique and crystal reveal monoclinic arrangement among space group P21/n. The parameters of lattice of NNNPB molecule and unit cell proportions were a = 9.9798(11) Å, b = 13.2737(13) Å, c = 13.0321(13) Å Volume = 1725.7(3) Å3. The experimental as well as theoretical FT-IR Raman spectral data verified the NNNPB molecules significant stretching vibration of the amide carbonyl (–C = O) function group. 1H 13C NMR spectral investigation was utilized to forecast the existence of proton and carbon in NNNPB compound. TGA and DTA study verified the various phases of the formed crystals degradation and revealed that it is thermally stable up to 150 °C. Quantum chemical calculations were carried out through density functional theory. The topological surface analysis of NNNPB were analysed through ELF and LOL. The virtual second-harmonic generation efficiencies deliberated by Kurtz- Perry powder manner along with are found to be 3.45 period better against potassium dihydrogen phosphate. The UV–vis spectral analysis confirmed the electronic excitations of NNNPB, showing high transparency in the deep ultraviolet region below 230 nm and above 320 nm. This optical behavior indicates its potential application in advanced laser systems. The calculated static first-order hyperpolarizability (β0 = 1.41 × 102 a.u.) and second-order hyperpolarizability (γo = 4.14 × 104 a.u.) reveal a strong nonlinear optical (NLO) response. Furthermore, at dynamic frequencies, the hyperpolarizability value increases to 8.73 × 104 a.u., demonstrating enhanced NLO performance. These results suggest that NNNPB is a promising candidate for optical technologies, particularly for improving second-harmonic generation and dc-Kerr effects.

The synthesis, characterization, and computational analysis of (E)-2-(3-ethoxy-4-hydroxybenzylidene)hydrazi-necarboxamide (EHBHC), an organic compound with potential nonlinear optical (NLO) properties is reported. The compound was synthesized by reacting 3-ethoxy-4-hydroxybenzaldehyde with semicarbazide in ethanol, followed by recrystallization to obtain high-purity single crystals. The crystal structure was determined using single-crystal X-ray diffraction (SCXRD), revealing a monoclinic system with the P21/c space group. Comprehensive spectroscopic analyses, including FT-IR, FT-Raman, and UV-visible spectroscopy, were performed to characterize the molecular vibrations and absorption properties. Density functional theory (DFT) computations using the B3LYP/6-311++G(d,p) basis set were conducted to investigate the structural, electronic, and NLO properties, providing insights into the molecular reactivity and charge distribution. Hirshfeld surface analysis highlighted key intermolecular interactions within the crystal. NLO properties, including hyperpolarizability, were evaluated, with the compound exhibiting promising hyperpolarizability values. Z-scan experiments confirmed the material's nonlinear absorption and optical limiting behavior, indicating its potential for applications in photonics and optoelectronics. This study highlights the synthesis and detailed characterization of EHBHC as a candidate for advanced NLO applications.

Hydrogels are 3D cross-linked networks that imbibe huge quantity of fluids without indissoluble. This peculiar property is due to its unique structural characteristics, which allows solutes to diffuse into the interior network of the hydrogels. The present investigation illustrates the synthesis of sustainable, superabsorbent hydrogels employing green monomers such as Almond gum, Citric acid and PVA, in an intuitive and economical manner. The synthesized hydrogels were characterized via FT-IR, XRD and SEM analysis. The results were corroborated by swelling behavior of hydrogel with respect to surface morphology. The percentage of swelling equilibrium at various pH levels, spanning from acidic to basic, has also been examined. The hydrogels reveals a rationalized swelling in basic medium over acidic medium. The bio-degradation of the sample could be attributed to the breakdown of ester linkage and hydrophilic pendant functionality found in hydrogel and it is strongly endorsed by the antibacterial investigations using gram positive and Gram negative pathogens. Grenoble green (Malachite green) was chosen as a cationic dye for removal from environmental sources via pH-sensitive bio-polymeric almond gum crosslinked with PVA and citric acid (APC) hydrogels. The results of dye removal demonstrated that APC hydrogels have an excellent dye removal efficiency. The impact of the hydrogel’s monomer composition on biodegradability, swelling and dye removal has also been critically examined. Consequently, the synthesized pH sensitive bio-polymeric hydrogels have a wider potential opening in diverse environmental and agricultural applications.

In this study, a bio-composite composed of TiO2-incorporated bio-silica (BS), silk fibroin (SF), and polyurethane foam (PUF) was developed and evaluated as a photocatalytic material for the removal of Turquoise Blue (TB) dye. The prepared bio-composite was analyzed for its formation, surface morphology, and thermal properties using FTIR, XRD, TGA, and SEM, respectively. The amorphous nature of the composite was clearly revealed through XRD and SEM studies. Initially, the composite adsorbed a substantial amount of the dye on its surface in the dark, after which it underwent photocatalysis under light exposure. The photodegradation efficiency of the BS/SF/PUF/TiO2 bio-composite for TB was assessed, and the results showed a significant enhancement in the photocatalytic degradation of TB compared to pure TiO2. The degradation efficiency of BS/SF/PUF/TiO2 reached approximately 99.96%. The high electron-hole charge separation capability was the driving force behind the consistent bandgap, which contributed to the exceptional photodegradation efficiency of the bio-composite. The bandgap of the BS/SF/PUF/TiO2 bio-composite was determined to be 2.9 eV. The photodegradation efficiency was evaluated by varying parameters such as pH, irradiation time, catalyst dosage, and initial dye concentration. The experimental data were fitted to the Langmuir-Hinshelwood model to analyze the rate constant and explore the possible photocatalytic mechanism. This study demonstrates that the BS/SF/PUF/TiO2 bio-composite holds significant potential as both an adsorbent and a photocatalyst for wastewater treatment, with the added advantage of being easily reusable.