The study in this paper presents a new material that was produced as a thin film by the Pulsed Laser Deposition technique (PLD) using a 532 nm wavelength and 150 mJ/pulse laser beam on the hemp stalk as target. The analyses performed by spectroscopic techniques (Fourier Transform Infrared Spectroscopy—FTIR, Laser—Induced Fluorescence Spectroscopy—LIF, Scanning Electron Microscopy coupled with Energy Dispersive X-ray—SEM-EDX, Atomic Force Microscopy—AFM and optical microscope) evidenced that a biocomposite consisting of lignin, cellulose, hemicellulose, waxes, sugars and phenolyc acids p-coumaric and ferulic, similar to the hemp stalk target was obtained. Nanostructures and aggregated nanostructures of 100 nm to 1.5 μm size were evidenced. Good mechanical strength and its adherence to the substrate were also noticed. It was noticed that the content in calcium and magnesium increased compared to that of the target from 1.5% to 2.2% and from 0.2% to 1.2%, respectively. The COMSOL numerical simulation provided information on the thermal conditions that explain phenomena and processes during laser ablation such as C-C pyrolisis and enhanced deposition of calcium in the lignin polymer matrix. The good gas and water sorption properties due to the free OH groups and to the microporous structure of the new biocomposite components recommends it for studies for functional applications in medicine for drug delivery devices, filters in dialysis and for gas and liquid sensors. Functional applications in solar cells windows are also possible due to the conjugated structures of the contained polymers.
Fluorescein sodium is a very important compound for a wide spectrum of applications, from which medical applications prevail. Despite this, there are very few studies in the literature related to the structure and fundamental properties of fluorescein sodium and its solutions, with most of the studies dealing with fluorescein. The purpose of the present article is to determine some parameters of the fluorescein sodium molecule approaching the quantum-mechanical modeling and experimental solvatochromism in both binary and ternary solutions. For data analysis, several theoretical models were applied. The results highlight the intermolecular interactions involved in the spectral shift of the electronic absorption band of fluorescein sodium when dissolved in different solvents or binary solvents and allowed the estimation of the difference between the interaction energy in molecular pairs of the type of fluorescein sodium − solvent 1 and fluorescein sodium − solvent 2. By applying a variational method, the dipole moment in the first excited state of the fluorescein sodium molecule and the angle between the dipole moments in the ground and excited states, respectively, were estimated. These results are useful for a better understanding of the behavior of fluorescein sodium when dissolved in different solvents or combinations of solvents, to develop new practical applications.