engleski

Hybrid cellulose-QDs composites – from synthesis to characterisation and possible application

Nowadays, there is a relentless search for new types of materials, especially those that could improve the conventional examples. Various composites or hybrid materials found wide applications due to their enhanced properties compared to materials already in use. For example, the use of cellulose, one of the most abundant natural polymers is still rare due to its insolubility in water and most organic solvents, hygroscopic nature, and other properties such as poor wettability, moisture absorption, etc. Thus, depending on the willing application, various modifications could be proposed to overcome these drawbacks. Looking at the field of semiconductors, such as various optical devices, photonics, fluorescent probes, etc., modification of cellulose could be done with fluorescent semiconductive material, namely CdSe quantum dots (QDs). Combining QDs with cellulose matrix should lead to stabilized QDs, and improve and highlight their functionality in general. Our goal is to develop a method for preparing well-defined hybrid nano- or microcellulose-QD composites with tunable optical properties. Synthetic procedures depend on the species of QD capping ligands and temperature in particular, as the key parameters for dynamics control. In this work, a comparison of nano and micro cellulose-QDs composites is presented. Prepared CdSe-cellulose composites are further characterised by UV-VIS, SEM, XRD, and contact angle measurements. XRD confirms composition with broad amorphous cellulose signal, while several wide diffraction lines are attributed to CdSe QDs. Moreover, microscopy and surface energy by CA measurements provided insight into the connectivity and miscibility of QDs and cellulose. Obtained results enable improvements in the course of the QDs preparation. The main goal is to gain control over the synthesis procedures necessary to produce this composite in a thin-film configuration, which is suitable for charge transfer layer application in solar cells and will be tested by Impedance spectroscopy.

QDs ; cellulose ; thin-film ; composite

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