Spectral, thermal and optical properties of adenosinium picrate: a nonlinear optical single crystal

Sustainable seedling pots: Development and characterisation of banana waste and natural fibre-reinforced composites for horticultural applications

Plastic pots used in horticultural nurseries generate substantial waste, causing environmental pollution. This study aimed to develop biodegradable composites from banana pseudo-stem reinforced with agricultural residues like pineapple leaves, taro and water hyacinth as eco-friendly substitutes. The aim of this study is to develop optimised banana biocomposite formulations with suitable reinforcements that balance mechanical durability, biodegradation, and seedling growth promotion properties to serve as viable eco-friendly alternatives to plastic seedling pots. This study was carried out by fabricating banana fibre mats through pulping, drying and hot pressing. Composite sheets were reinforced with 50 % pineapple, taro or water hyacinth fibres. The mechanical properties (tensile, yield strength, elongation, bursting strength), hydrophilicity (contact angle, water absorption), biodegradability (soil burial test), and seedling growth promotion were evaluated through appropriate testing methods. The results show that banana-taro composites exhibited suitable tensile strength (25 MPa), elongation (27 %), water uptake (41 %) and 82 % biodegradation in 60 days. It was observed that biodegradable seedling trays fabricated from banana-taro composite showed 95 % tomato seed germination and a 125 cm plant height increase in 30 days, superior to plastic trays. The finding shows that the study demonstrates the potential of banana-taro biocomposites as alternatives to plastic nursery pots, enabling healthy seedling growth while eliminating plastic waste pollution through biodegradation.

Synthesis, growth, optical, mechanical, thermal, dielectric, and SHG properties of Triethylaminium picrate (TEAP) single crystal for nonlinear optical applications

Triethylaminium picrate (TEAP) crystals were grown using the slow evaporation solution growth method at ambient (35 °C) temperature. Salt was synthesized from Picric acid, and Triethylamine and methanol was used as solvents. The solution was mixed at a 1:1 ratio and evaporated slowly, produced yellow colour single crystal of TEAP with an average dimension of 19 × 8 × 5 mm3. The structure of the compound was determined by single-crystal X-ray diffraction (SCXRD) study, which confirms that the crystal is belongs to Orthorhombic crystal system, and its crystallinity was confirmed by the Bragg peak in the powder X-ray diffraction pattern. The superamolecular characteristic of the TEAP was confirmed by the Hirshfield analysis. CHN elemental analysis confirmed the stoichiometry and chemical composition of the synthesized complex salts. FT-IR and Polarized Raman spectral analyses confirmed the presence of different functional groups in the complex. UV-vis-NIR study identified the optical transmission window and the lower (TEAP) cut-off wavelength. Vickers' microhardness analysis determined the mechanical stability of the grown crystal. Studies of dielectric and AC conductivity were analyzed as a function of frequency. The thermogravimetry (TG) and differential thermal analysis (DTA) techniques were used to investigate the thermal behaviour of the material. The Kurtz-Perry powder technique was used to analyze the crystal's nonlinear optical properties (NLO) and found that its SHG efficiency was 1.5 times higher than that of potassium dihydrogen phosphate (KDP). The results from the obtained characterizations conclude that the TEAP crystal could be useful for NLO applications.

Co-crystals, Salts or Mixtures of Both? The Case of Tenofovir Alafenamide Fumarates

Tenofovir alafenamide fumarate (TAF) is the newest prodrug of tenofovir that constitutes several drug products used for the treatment of HIV/AIDS. Although the solid-state properties of its predecessor tenofovir disoproxil fumarate have been investigated and described in the literature, there are no data in the scientific literature on the solid state properties of TAF. In our report, we describe the preparation of two novel polymorphs II and III of tenofovir alafenamide monofumarate (TA MF2 and TA MF3). The solid-state structure of these compounds was investigated in parallel to the previously known tenofovir alafenamide monofumarate form I (TA MF1) and tenofovir alafenamide hemifumarate (TA HF). Interestingly, the single-crystal X-ray diffraction of TA HF revealed that this derivative exists as a co-crystal form. In addition, we prepared a crystalline tenofovir alafenamide free base (TA) and its hydrochloride salt (TA HCl), which enabled us to determine the structure of TA MF derivatives using ¹⁵N-ssNMR (¹⁵N-solid state nuclear magnetic resonance). Surprisingly, we observed that TA MF1 exists as a mixed ionization state complex or pure salt, while TA MF2 and TA MF3 can be obtained as pure co-crystal forms.

Growth, structure, spectral and optical properties of semiorganic crystal: Pyridine-1-ium-2-carboxylatehydrogenbromide

Pyridine-1-ium-2-carboxylatehydrogenbromide (PHBr) crystal was grown from aqueous solution by slow evaporation method. The calculated lattice parameters of single crystal X-ray diffraction have shown the triclinic crystal system with centrosymmetric space group of Pī. The interaction of functional groups and their importance in their application was identified by FTIR spectral analysis. The material is optically transparent and the grown crystal is having lower cut off wavelength as 294nm, thereby confirming the enhancement of non-linear optical (NLO) property and optical band gap of the PHBr have been determined as 2.49eV by UV-Vis-NIR studies. The (1)H NMR spectrum confirms the molecular structure and the presence of different kinds of protons.

Synthesis, crystal growth and physiochemical characterization of organic NLO crystal: L-ornithinium dipicrate (LODP)

L-ornithinium dipicrate (LODP) has been synthesized and good quality single crystals were grown by slow evaporation method at room temperature. Single crystal XRD confirms that the grown crystal belongs to the monoclinic system with the noncentrosymmetric space group P21. Powder X-ray diffraction study confirms the crystalline nature of the compound. FTIR spectral analysis confirms the functional group in the synthesized compound. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. The optical absorption spectrum shows the absence of absorption between 475 nm and 800 nm. The dielectric measurements were carried out to estimate the dielectric parameters of the grown crystal in the frequency range from 50 Hz to 5 MHz at various temperatures. The second harmonic property has been investigated by Kurtz-Perry powder technique. The relative SHG efficiency of LODP is found to be 14.57 times greater than that of the reference material KDP.

Experimental and theoretical studies of 2,5-dichloroanilinium picrate

Organic 2,5-dichloroanilinium picrate crystal was grown by using slow evaporation solution technique. The lattice parameter was estimated by powder X-ray diffraction. The absence of absorption at around Nd:YAG fundamental wavelength was confirmed by ultraviolet-visible absorption study. The vibrational analyses confirm the various functional groups present in the grown crystal. The NMR study confirms the presence of chemical environment of hydrogen in the title crystal. The thermogravimetric (TG), differential thermal analysis (DTA) and differential scanning calorimetry (DSC) traces reveals the thermal stability of the compound. The second harmonic generation (SHG) of the crystal was confirmed by Kurtz Perry powder technique. The theoretical studies such as first-order hyperpolarizability (β), molecular orbitals, electronic excitation and electrostatic potential (ESP) were performed using Gaussian 03W software at HF/6-31G (d) level.