International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The preparation of XRF tablets with small amounts of samples produced from various synthesis is a challenging operation. Zeolites and other types of samples with minimal volumes are frequently provided for analysis by X-ray fluorescence spectroscopy. Here we present three types of holders made of PLA (polylactic acid) using commercially available 3D printing technology. The employed material is a bioactive thermoplastic aliphatic polyester extracted from renewable resources and is biodegradable. The holders have reduced diameters of the measured area and can accommodate powders, sheets or solid state samples. The holders are basically three-dimensional plastic models that can be designed and printed based on the provided sample. They are low cost and can be easily applied in practice. The design of the first type of holders is targeting powder samples, allowing the reduction of the required amount from 5-10 g per sample to 1 g. The second type of holders aimed the XRF analyses of textile like materials while the third type of design aimed metal alloys. Examples of the use of the holders are the analyses of coins (here 2 leva is shown) and textile samples containing different metals (e.g. zinc).

We focused on the synthesis and subsequent use of mesoporous titanosilicate ETS-10 for industrial water purification. Numerous attempts have been made to optimize the conditions and reagents used for the synthesis of the ETS-10. The main problem we faced in the synthesis of ETS-10 is the production of “pure” phase and it was related to the type of titanium source. Various sources of titanium were used – titanium tetrachloride, anatase (anatase 92% and rutile 6%), nanosized titanium dioxide (Degussa P25) etc. The use of liquid titanium tetrachloride, due to its high hydrophilicity, leads to difficulties in reproducible control of the quantities of used reagents, which leads to the formation of unwanted crystalline phases, especially if the synthesis is carried out in small volumes. In addition, the optimized by us synthesis attempts included a reduced reaction time – up to 24 hours – and lower temperatures (up to 200 oC). For comparison standard synthesis is carried out for 72 h at 230 oC. As a result of the experiments, ETS-10 with minimal SiO2 residues was obtained in 24 hours at 200 oC using nanosized anatase.