The Effect of Nano-Zinc Oxide and Nano-Titanium Dioxide on Inhabitation of Ochratoxin A

The experiment was conducted at the Agricultural Research Office in Baghdad during July 2020 to test the ability of nanomaterials (ZnO and TiO2) to inhibit ochratoxin A, which is produced by a number of microbiology (fungi) including: Aspergillus ochraceus, A. niger, ,A. steynii, A. carbonarius, Pencillume verrucosum and P. nordicum. The standard ochratoxin A, with known concentration, was treated with different concentrations of nanomaterials (20, 40, 60, and 80 ppm) and two different particle sizes of nanoparticles approximately (15 nm) and (70 nm) for each (ZnO) and TiO2; with 16 transactions. Through an examination of the HPLC, the results showed that all transactions led to a noticeable inhibition in the concentration of ochratoxin A, and the highest inhibition rate was for ZnO nanoparticles with particle-size (70 nm) and 80 ppm concentration, where the inhibition rate was 99%. In other hand, the TiO2 nanoparticles with particle-sized (70 nm) and the concentration (80 ppm) were followed by 95%.

Synthesis and Characterization of High Surface Area Nano Titanium Dioxide

TiO2 and TiO2-Al2O3 nanoparticles were synthesized via sol-gel method using hydrolysis of Titanium tetraisopropoxide (TTIP) with ethanol and water mixture as titania source. TiO2-Al2O3 Nano-composite was successfully synthesized using the sol-gel technique. Tetraisopropoxide and aluminium isopropoxide were used to prepare TiO2-Al2O3. All prepared samples calcination were conducted at different temperature (400 to 700) oC. The synthesized TiO2 and TiO2-Al2O3 nanocomposites were then characterized by XRD, AFM, BET surface area, SEM, XRF. XRD, the analysis showed that the presence of alumina (Al2O3) in the TiO2 has an effect on crystal size, particles size, surface area, and crystal phases; The XRD result revealed that the prepared TiO2 nanoparticles were anatase phase at 400oC, and 500oC, and transformed to rutile from 600oC to 700oC, but after addition of alumina TiO2 was of anatase phase, without any rutile at all calcination temperatures, also, the addition of alumina leads to a significant decrease in the crystal size, particles size, especially at high temperatures while the surface area of pure titanium was increased, and this corresponds to the results of the AFM and SEM. The best-obtained surface area was 355.18 m2/ gm. with 34.98 nm of average particle size at 500oC in comparison with pure nano titanium dioxide

Study on the Electrochemical Technology and Nanotechnology of Composite Electrode Used as An Alternative to Ultraviolet Light

Advanced oxidation technology has the advantage of being able to efficiently degrade refractory organics, and plays an important role in the treatment of industrial organic wastewater. The article analyses its role in the purification of organic wastewater by the electrochemical method of polymer composite nano-titanium dioxide. The oxygen evolution potential of the nano titanium dioxide electrode is up to 2.8V, showing excellent electrochemical performance. Didache, Si/BDD, Nb/BDD, It/BDD electrodes and surface-modified BDD electrodes can generate strong oxidizing hydroxyl radicals on the surface of the electrodes, which are organic to phenols, dyes, pesticides, and surfactants. The degradability of wastewater is strong. Nano-titanium dioxide electrodes can degrade a variety of organic matter, with a current efficiency of >90%, and can completely mineralize organic matter. Nano-titanium dioxide electrodes have good application prospects in organic wastewater treatment.

Antifungal Effect of Chitosan/Nano-TiO2 Composite Coatings against Colletotrichum gloeosporioides, Cladosporium oxysporum and Penicillium steckii

Postharvest pathogens such as C. gloeosporioides (MA), C.oxysporum (ME) and P. steckii (MF) are the causal agents of disease in mangoes. This paper presents an in vitro investigation into the antifungal effect of a chitosan (CTS)/nano-titanium dioxide (TiO2) composite coating against MA, ME and MF. The results indicated that, the rates of MA, ME and MF mortality following the single chitosan treatment were 63.3%, 84.8% and 43.5%, respectively, while the rates of mycelial inhibition were 84.0%, 100% and 25.8%, respectively. However, following the addition of 0.5% nano-TiO2 into the CTS, both the mortality and mycelial inhibition rates for MA and ME reached 100%, and the mortality and mycelial inhibition rate for MF also increased significantly, reaching 75.4% and 57.3%, respectively. In the MA, the dry weight of mycelia after the CTS/0.5% nano-TiO2 treatment decreased by 36.3% in comparison with the untreated group, while the conductivity value was about 1.7 times that of the untreated group, and the protein dissolution rate and extravasation degree of nucleic acids also increased significantly. Thus, this research revealed the potential of CTS/nano-TiO2 composite coatings in the development of new antimicrobial materials.