Nuova ricerca


Assegnista di ricerca presso: Centro Intrerdipartimentale di Ricerca e per i Servizi nel settore delle Costruzioni e del Territorio CRICT - UNIMORE

TITOLARE DI BORSA DI STUDIO presso: Dipartimento di Ingegneria "Enzo Ferrari"

Home |


2020 - First insights into photocatalytic degradation of HDPE and LDPE microplastics by a mesoporous N-TiO2 coating: Effect of size and shape of microplastics [Articolo su rivista]
Llorente-Garcia, B. E.; Hernandez-Lopez, J. M.; Zaldivar-Cadena, A. A.; Siligardi, C.; Cedillo-Gonzalez, E. I.

Microplastics (MPs), which are small plastic debris of ≤5 mm size, are polluting the oceans with negative consequences for their biota. In this work, visible-light photocatalysis of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) MPs in aqueous medium using a mesoporous N-TiO2 coating is proposed as an alternative for fighting MP pollution. Spherical primary HDPE MPs were extracted from commercially available facial scrubs, while film-shaped secondary LDPE MPs were obtained from a plastic bag. For each plastic, two different sizes were tested. Degradation was measured by mass-loss and carbonyl-index (CI) calculation. The results obtained reveal that the photocatalytic degradation of HDPE and LDPE MPs using an N-TiO2 coating was affected by the size and shape of the MPs. Smaller MPs led to higher degradation, while film-shaped MPs led to lower degradation that was related to a poorly illuminated and oxygenated reaction medium. These results set the basis for further investigation on the on the design of more effective photocatalytic-reaction systems for decreasing MP inputs to the environment.

2020 - Microplastic pollution reduction by a carbon and nitrogen-doped TiO2: Effect of pH and temperature in the photocatalytic degradation process [Articolo su rivista]
Ariza-Tarazona, M. C.; Villarreal-Chiu, J. F.; Hernández-López, J. M.; Siligardi, C.; Cedillo-González, E. I.

Microplastics (MPs) are pollutants formed by plastics ≤ 5 mm and are present in marine and terrestrial environments. Due to their large surface to volume ratio and chemical surface properties, MPs adsorb hazardous chemicals from their surrounding environment. When MPs are consumed by fauna, they transfer those substances through the trophic chain. An essential issue of MPs is their disposal. Due to their size, the disposal methods commonly used for plastic items are not suited for MPs. Here, photocatalysis in an aqueous medium is proposed as an alternative to fight MPs pollution. Although the photocatalysis of MPs has been reported, the effect of operating variables in the process has not been investigated. To fill this gap, the impact of pH and temperature on the degradation process of HDPE MPs was investigated using C,N-TiO2 and visible light. Degradation was followed by mass loss, carbonyl index calculation and microscopy. It was found that photocatalysis at low temperature (0 °C) increases MPs’ surface area by fragmentation, and low pH value (pH 3) favours hydroperoxide formation during photooxidation. By using the design of experiments tool, it was demonstrated that there is a combined effect of pH and temperature in the photocatalysis of HDPE

2019 - New strategy for microplastic degradation: Green photocatalysis using a protein-based porous N-TiO2 semiconductor [Articolo su rivista]
C Ariza-Tarazona, M.; Villarreal-Chiu, J. F.; Barbieri, Virginia; Siligardi, Cristina; CEDILLO GONZALEZ, ERIKA IVETH

Currently, the global community considers microplastics as a marine pollutant of emerging concern. To mitigate the oceanic microplastic pollution, it is necessary to reduce inputs from inland. In this sense, we present the first report on the use of photocatalysis for the degradation of HDPE microplastics extracted from a commercially available facial scrub. This was achieved by using two proposed semiconductors based on N-TiO2. One was green synthesized using the extrapallial fluid of fresh blue mussels, which presented an excellent capacity to promote photocatalytic degradation in solid and aqueous environments; while the second photocatalyst, obtained from a conventional sol-gel synthesis, presented good capacity to promote mass loss of the as-extracted microplastics in an aqueous environment. Mass losses, SEM and FTIR analysis confirmed HDPE degradation. Results showed that environmental conditions, microplastics/N-TiO2 interaction and the N-TiO2 surface area should be carefully set and monitored in order of avoiding the arrest of photocatalysis

2018 - Below room temperature:how the photocatalytic activity of dense and mesoporous TiO2 coatings is affectes" [Articolo su rivista]
Cedillo Gonzalez, E. I.; Ricco', Rossella; Costacurta, S.; Siligardi, C.; Falcaro, P.

Different parameters such as morphology, porosity, crystalline phase or doping agents affect the self-cleaning performance of photocatalytic TiO2-based coatings. However, also environmental conditions have been found to play a major role on the photocatalytic self-cleaning property. Substrate temperature is a significant environmental variable that can drastically affect this process. This variable becomes of great importance especially for outdoor applications: many self-cleaning photocatalytic materials have been designed to be exposed to outdoor environments and consequently, can be exposed to variable temperatures depending on the season of the year and the typical weather of the geographical zone. Thus, understanding the influence of the most common outdoor temperatures on the self-cleaning performance of TiO2-based coatings is essential for the fabrication of any kind of photocatalytic self-cleaning materials (fabricated by coating technology) that is expected to be subjected to outdoor environments. In this work, the photocatalytic activity was studied by Fourier Transformed Infrared (FTIR) Spectroscopy varying the temperature in the 0 to 30 °C range for dense and mesoporous TiO2 coatings. The temperature conditions at which these coatings present better performances were identified, providing a deeper insight for the practical application of TiO2-based self-cleaning coatings. © 2017 Elsevier B.V.

2018 - Silica coating for interphase bond enhancement of carbon and AR-glass Textile Reinforced Mortar (TRM) [Articolo su rivista]
Signorini, C.; Nobili, A.; Cedillo González, E. I.; Siligardi, C.

In this paper, we investigate the effect of silica nano-coating for interphase bond enhancement on the mechanical performance of Textile Reinforced Mortar (TRM) composite materials aimed at structural rehabilitation and strengthening. Alkali-resistant glass (ARG) and carbon fabric reinforcements are preliminarily treated via sol-gel deposition of SiO2coating to promote bond formation capability with the mortar matrix. Optical and electron microscopy provide evidence of interphase bond enhancement. Mechanical performance is assessed both in traction, through uni-axial elongation of prismatic coupons, and in flexure, by three-point bending of laminated masonry bricks. Results are given in terms of mean strength curves, ultimate and design strength and strain values, cracked and uncracked moduli, mean crack spacing, mean crack width and energy dissipation. It is shown that mean absolute performance of silica coating offers a significant improvement over uncoated fabric, yet it is inferior to that of specimens which have been treated with a liquid partially-organic adhesion promoter (polymer coating). However, when design values are considered which incorporate the dispersion of experimental data, silica coating proves superior or at least equivalent to polymer coating, respectively for carbon and ARG fabric. These promising results describe the first application of silica nano-coating to fabric reinforced composite materials.

2016 - Evaluation of the correlations between temperature, humidity, incident UV light and the photocatalytic activity of TiO2films using a rationale approach [Articolo su rivista]
Cedillo Gonzalez, Erika Iveth; Mugoni, Consuelo; Montorsi, Monia

The effect of temperature, humidity and incident UV light on the photocatalytic activity of two TiO2filmswith different microstructures (dense and mesoporous) was explored in terms of stearic acid degradation.Previous works reported in the literature suggest that the activity of TiO2films does not only depend onsingle factors but also on interactions between them. Hence, the design of experiments (DoE) approachwas used in this work to plan the experiments in a systematic way, simultaneously considering severalvariables. This approach provided an efficient working strategy to explore both individual and interactioneffects on the photocatalytic activity of the films. The statistical evidence found here revealed that singlefactors temperature and mesoporous microstructure have the strongest positive effect on the efficiencyof the films. In the case of temperature, this was explained by easier degradation and/or desorption ofreaction intermediates. On the other hand, the positive effect of the mesoporous microstructure wascorrelated with its large surface area. An interaction factor between temperature and incident UV lightalso affects the activity of the films. Results suggest that this phenomenon depends of the degree of filmhydration before the deposition of SA.