Photo-induced antifungal activity of chitosan composite film solution with Nano TiO2 and Nano Ag

This study investigated the ultraviolet (UV) light-induced effect of chitosan-titanium dioxide-silver (CTS-TiO2-Ag) nanocomposite film solution against Penicillium steckii ( ( P. steckii ) , as well as the underlying the physiological mechanism. The results indicated that the longer the UV exposure time, the better the pathogenic inhibition effect. After UV photoinduced treatment for 120 min, the colony diameter of P. steckii was the smallest at 4.85 mm. However, when this process is followed by an 8-h storage period, the conductivity of the P. steckii culture medium reached its highest level at 713 μs/cm. After a 120 h growth period in the same conditions, the lesion diameters and pathogenicity of the mangoes reached 12.61 mm and 41.67%, respectively. Since the cell membrane was severely disrupted, its permeability increased, causing serious intracellular protein and nucleic acid material extravasation. Furthermore, the malondialdehyde (MDA) , catalase (CAT) and superoxide dismutase (SOD) in the P. steckii reached maximum levels after 8 h of incubation, at 2.1106 μmol/mL, 44.06 U/mL, and 24.67 U/mL respectively. These results indicated significant P. steckii inhibition via the UV light induction of the CTS-TiO 2 -Ag composite film solution.

Surface modification of nano-TiO2 with lanthanide-acetylacetonate complexes

The surface modification of nano-TiO2 was carried out with lanthanide-acetylacetonate complexes by adsorption method. The effects of lanthanide complexes content, lanthanide element type, adsorption temperature, solvent dosage, adsorption time and other conditions on the photodegradation activity of methyl orange by the modified catalyst were studied, and suitable modification conditions were obtained. The results show that the photocatalytic activity of the modified nano-TiO2 is much higher than that of the unmodified pure TiO2, and the lanthanide-acetylacetonate complexes is an excellent surface modifier.

Functionalization of Smart Recycled Asphalt Mixtures: A Sustainability Scientific and Pedagogical Approach

The sustainable development of our societies demands strong efforts on scientific and technological research while informing and educating students and the general population. Air pollution and road safety hazards constitute two main public health problems that are insufficiently addressed pedagogically. With this work, we aim to contribute to tackeling the problem by presenting the results of scientific research on the development of photocatalytic, superhydrophobic, and self-cleaning recycled asphalt mixtures to achieve an eco-social friendly and smart material able to mitigate socioenvironmental impacts. The functionalization of asphalt is implemented by spraying particles’ solutions over a conventional AC 10, then evaluated by dye degradation and wettability. Firstly, different particles’ solutions (with nano-TiO2 and/or micro-PTFE under water, ethyl alcohol, and dimethyl ketone) were sprayed to select the best solution (BS), which was composed of TiO2-PTFE (4 g/L each) in ethyl alcohol. Two successive spraying coatings (diluted epoxy resin and BS) were performed over conventional and recycled AC 10 (with reclaimed asphalt pavement and steel slags). Their efficiency decreases with the highest resin amounts. The best results were obtained with 0.25 g resin and BS. For the lowest resin amount, all mixtures achieved superhydrophobicity and performed similarly regarding wettability.

A review of the effect and optimization of use of nano-TiO2 in cementitious composites

There are some problems and weaknesses related to cement-based materials, such as their very low tensile strength, low chemical resistance and the huge contribution of cement production to industrial CO2 emissions. One possible method to reduce the impacts of such problems is the partial replacement of cement in cementitious materials with nano materials. This work provides a detailed review of incorporation of one of the most widely used nano materials, namely nano-titanium dioxide, and its effect on the properties of cementitious composites. Different properties have been considered in the current study, such as fresh properties, mechanical properties (compressive strength, split tensile strength and flexural strength), durability (permeability, ultrasonic pulse velocity (UPV), electrical resistivity, carbonation resistance, freeze and thaw resistance and sulfate attack resistance) and microstructural properties. This paper also investigates the optimum content of nano-TiO2 in cement-based materials. Moreover, the cost effectiveness of use on nano-titania in cementitious composites has been discussed. Nano titania reduces the workability and setting time of cement-based materials. It can be very effective in improving the mechanical properties, durability and microstructural properties of cementitious composites.