Alexandru Cocean

Hemp stalks have been used since ancient times for what we call “bast fibers”, mainly in textile clothing. Also the hurds have been paid attention to and found utilization in construction as reinforcing component in what is recently called as “hempcreate”. This research explores new possibilities for valorizing hemp stalks in the current context when this plant is of increasing interest to be cultivated. Nano-biocomposite new materials were produced under this study for medical applications in transdermal patches and as component in new solar cells. The new material was characterized by spectroscopic and microscopic methods (FTIR, LIF, AFM and SEM-EDX) and it was found that all of the hemp stalk components were deposited in a nanostructured thin film, a replica of the natural biocomposite used as target. In order to better understand the physico-chemical phenomena and processes during laser ablation, the COMSOL numerical simulation was used. The influence of calcium on the heating and ablation of lignin were evaluate with this method. The simulation highlights the role of the higher absorbent components to induce heat diffusion in the less absorbent components of the biocomposite and enhance laser ablation effects on both components. The numerical model used for the simulation conducted in COMSOL is validated by the results of pulsed laser deposition analyzed by the spectroscopic methods. The good gas and water sorption properties due to the free hydroxyl groups and to the microporous structure of the new nano-biocomposite material recommends it for further applications in medicine for transdermal patches, filters in dialysis and for gas and liquid sensors. The conjugated chemical structures of the component compounds indicate that the new material is suitable as component in solar cells windows. The research was conducted by the Atmosphere Optics, Spectroscopy and Lasers Laboratory

Audience Take Away:

• The audience will learn about absolutely new possibilities of harnessing hemp stalks as nanoparticles forming thin films obtained by laser ablation and deposition on various supports both for the medical field and for the production of solar cells.
• The thin layers thus obtained can be used in various fields (medical, optoelectronics, etc.) to develop various devices such as transdermal patches, solar cells, sensors that include them in their structure, as well as for other applications starting from their physical, chemical properties and their micro and nanostructure as they are analyzed and presented in the proposed exposition.
• The research containing the study with COMSOL simulation has been published and the information can be used in universities by faculties of agronomy, biology, physics, chemistry, pharmacy, computer sciences as well as in a multitude of technical and technological research fields.
• This research provides a model of numerical simulation in COMSOL for laser interaction with the components of the hemp stalk as a solution for designing more efficiently the pulsed laser deposition of nanostructures and thin films from biocomposites and for improving the accuracy of the technique.
• It also provides a solution on designing nano-structures from biocomposite materials using pulsed laser deposition technique (PLD) and to properly understand their characteristics and behavior under pulsed laser irradiation.