Protective fibrous structures based on cellulose fibers functionalized with metal oxide nanoparticles by electrospinning and electrospray deposition.

This work aims to develop a bio-based fibrous material that is able to adsorb and degrade chemical and biological hazardous agents. Thus, cellulosic fabrics (flax) were functionalized with chitosan (CS) and poly(ethylene oxide) (PEO) electrospun nanofibers doped with titanium dioxide (TiO) and cerium dioxide (CeO) nanoparticles (NPs). The electrospray deposition of these NPs was also tested.

Peroxydisulfate Activation by Carbon Materials for the Degradation of the Herbicide Ametryn in Waters.

Brazil, the largest global sugar cane producer, utilizes approximately 10 million hectares for cultivation. However, the increased use of agrochemicals in this industry raises concerns about environmental and human health impacts. Inclusively, ametryn (AMT), a pesticide intensively used in sugar cane plantations, has been detected in several water matrices at concerning levels, which evidences the urgent need for the development of technologies capable of removing this pesticide from the environment.

Antibiofilm Effect of Nitric Acid-Functionalized Carbon Nanotube-Based Surfaces against and .

Chemically modified carbon nanotubes are recognized as effective materials for tackling bacterial infections. In this study, pristine multi-walled carbon nanotubes (p-MWCNTs) were functionalized with nitric acid (f-MWCNTs), followed by thermal treatment at 600 °C, and incorporated into a poly(dimethylsiloxane) (PDMS) matrix. The materials' textural properties were evaluated, and the roughness and morphology of MWCNT/PDMS composites were assessed using optical profilometry and scanning electron microscopy, respectively.

Exploring Nitrogen-Functionalized Graphene Composites for Urinary Catheter Applications.

Graphene has been broadly studied, particularly for the fabrication of biomedical devices, owing to its physicochemical and antimicrobial properties. In this study, the antibiofilm efficacy of graphene nanoplatelet (GNP)-based composites as coatings for urinary catheters (UCs) was investigated. GNPs were functionalized with nitrogen (N-GNP) and incorporated into a polydimethylsiloxane (PDMS) matrix.

Optimization of iron-ZIF-8 catalysts for degradation of tartrazine in water by Fenton-like reaction.

Optimization of iron zeolitic imidazole framework-8 (FeZIF-8) nanoparticles, as heterogeneous catalysts, were synthesized and evaluated by the Fenton-like reaction for to degrade tartrazine (Tar) in aqueous environment. To achieve this, ZIF-8 nanoparticles were modified with different iron species (Fe or FeO), and subsequently assessed through the Fenton-like oxidation. The effect of different parameters such as the concentration of hydrogen peroxide, the mass of catalyst and the contact time of reaction on the degradation of Tar by Fenton-like oxidation was studied by using the Box-Behnken design (BBD).

Combination of CNTs with Classical Drugs for Treatment in Human Colorectal Adenocarcinoma (HT-29) Cell Line.

Due to the increase in new types of cancer cells and resistance to drugs, conventional cancer treatments are sometimes insufficient. Therefore, an alternative is to apply nanotechnology to biomedical areas, minimizing side effects and drug resistance and improving treatment efficacy. This work aims to find a promising cancer treatment in the human colorectal adenocarcinoma cell line (HT-29) to minimize the viability of cells (IC) by using carbon nanotubes (CNTs) combined with different drugs (5-fluorouracil (5-FU) and two repurposing drugs-tacrine (TAC) and ethionamide (ETA).

The Use of 3D Optical Coherence Tomography to Analyze the Architecture of Cyanobacterial Biofilms Formed on a Carbon Nanotube Composite.

The development of environmentally friendly antifouling strategies for marine applications is of paramount importance, and the fabrication of innovative nanocomposite coatings is a promising approach. Moreover, since Optical Coherence Tomography (OCT) is a powerful imaging technique in biofilm science, the improvement of its analytical power is required to better evaluate the biofilm structure under different scenarios. In this study, the effect of carbon nanotube (CNT)-modified surfaces in cyanobacterial biofilm development was assessed over a long-term assay under controlled hydrodynamic conditions.

Performance of Graphene/Polydimethylsiloxane Surfaces against and Single- and Dual-Species Biofilms.

The increasing incidence of implant-associated infections has prompted the development of effective strategies to prevent biofilm formation on these devices. In this work, pristine graphene nanoplatelet/polydimethylsiloxane (GNP/PDMS) surfaces containing different GNP loadings (1, 2, 3, 4, and 5 wt%) were produced and evaluated on their ability to mitigate biofilm development. After GNP loading optimization, the most promising surface was tested against single- and dual-species biofilms of and .

Solar Light-Induced Methylene Blue Removal over TiO/AC Composites and Photocatalytic Regeneration.

TiO-containing photocatalysts, which combine TiO with carbon-based materials, are promising materials for wastewater treatment due to synergistic photodegradation and adsorption phenomena. In this work, TiO/AC composites were produced by the in situ immobilization of TiO nanoparticles over activated carbon (AC) derived from spent coffee grains, using different TiO/AC proportions. The TiO/AC composites were tested as adsorbents (dark) and as photocatalysts in a combined adsorption+photocatalytic process (solar irradiation) for methylene blue (MB) removal from ultrapure water, and from a secondary effluent (SecEf) of an urban wastewater treatment plant.

Highly N-Selective Activated Carbon-Supported Pt-In Catalysts for the Reduction of Nitrites in Water.

The catalytic reduction of nitrites over Pt-In catalysts supported on activated carbon has been studied in a semi-batch reactor, at room temperature and atmospheric pressure, and using hydrogen as the reducing agent. The influence of the indium content on the activity and selectivity was evaluated. Monometallic Pt catalysts are very active for nitrite reduction, but the addition of up to 1 wt% of indium significantly increases the nitrogen selectivity from 0 to 96%.

Carbon Nanotube/Poly(dimethylsiloxane) Composite Materials to Reduce Bacterial Adhesion.

Different studies have shown that the incorporation of carbon nanotubes (CNTs) into poly(dimethylsiloxane) (PDMS) enables the production of composite materials with enhanced properties, which can find important applications in the biomedical field. In the present work, CNT/PDMS composite materials have been prepared to evaluate the effects of pristine and chemically functionalized CNT incorporation into PDMS on the composite's thermal, electrical, and surface properties on bacterial adhesion in dynamic conditions. Initial bacterial adhesion was studied using a parallel-plate flow chamber assay performed in conditions prevailing in urinary tract devices (catheters and stents) using as a model organism and PDMS as a control due to its relevance in these applications.

Optimization of the preparation conditions of cordierite honeycomb monoliths washcoated with cryptomelane-type manganese oxide for VOC oxidation.

Ceramic honeycomb monoliths were washcoated with cryptomelane-type manganese oxides and their catalytic performance was evaluated in the oxidation of ethyl acetate. The effect of a mixture of ethyl acetate with toluene and of the presence of water vapour was also assessed.Different coating parameters, namely size of catalyst particles, number of immersions in the washcoating solution, presence of an initial coating with alumina, calcination temperature of this coating, as well as the amount of binding agent and ethanol in the washcoating solution were studied and optimized based on the catalytic activity of the structured catalyst.

Catalytic and Photocatalytic Nitrate Reduction Over Pd-Cu Loaded Over Hybrid Materials of Multi-Walled Carbon Nanotubes and TiO.

TiO and carbon nanotube-TiO hybrid materials synthesized by sol-gel and loaded with 1%Pd-1%Cu (%.) were tested in the catalytic and photocatalytic reduction of nitrate in water in the presence of CO (buffer) and H (reducing agent). Characterization of the catalysts was performed by UV-Vis and fluorescence spectroscopy, X-ray diffraction, temperature programed reduction, N adsorption, and electron microscopy.

Effect of ball milling on the catalytic activity of cryptomelane for VOC oxidation.

Cryptomelane-type manganese oxides prepared by a solvent-free method were evaluated as catalysts for the oxidation of ethyl acetate, ethanol and toluene. The original catalyst (K-OMS-2) presented high catalytic activity for ethyl acetate and ethanol oxidation, achieving 90% conversion into CO around 200°C for both pollutants. Toluene was much harder to oxidize, requiring a temperature near 270°C for the same conversion.

Ethyl Acetate Abatement on Copper Catalysts Supported on Ceria Doped with Rare Earth Oxides.

Different lanthanide (Ln)-doped cerium oxides (Ce0.5Ln0.5O1.

Naphthopyran-Based Silica Nanoparticles as New High-Performance Photoresponsive Materials.

Hybrid nanomaterials based on the covalent grafting of silylated naphthopyrans (NPTs) onto silica nanoparticles (SiO2 NPs) were successfully prepared and studied as new photochromic materials. They were prepared by a two-step protocol consisting of (i) NPTs (derivatives from 2H-naphtho[1,2-b]pyran (2H-NPT) and 3H-naphtho[2,1-b]pyran (3H-NPT)) silylation by a microwave-assisted reaction between hydroxyl-substituted NPTs and 3-(triethoxysilyl)propyl isocyanate, followed by (ii) covalent post-grafting onto SiO2 NPs. In order to study the role of the silylation step, the analogous non-silylated nanomaterials were also prepared by direct adsorption of NPTs.

Nitrate reduction over a Pd-Cu/MWCNT catalyst: application to a polluted groundwater.

The influence of the presence of inorganic and organic matter during the catalytic reduction of nitrate in a local groundwater over a Pd-Cu catalyst supported on carbon nanotubes was investigated. It was observed that the catalyst performance was affected by the groundwater composition. The nitrate conversion attained was higher in the experiment using only deionized water as solvent than in the case of simulated or real groundwater.

Effect of support and pre-treatment conditions on Pt-Sn catalysts: application to nitrate reduction in water.

The effect of the support (activated carbon or titanium dioxide) on the catalytic activity and selectivity to nitrogen of Pt-Sn catalysts in nitrate reduction was studied. The effects of the preparation conditions and the Pt:Sn atomic ratio were also evaluated. It was observed that the support plays an important role in nitrate reduction and that different preparation conditions lead to different catalytic activities and selectivities.

Ozonation of textile effluents and dye solutions under continuous operation: Influence of operating parameters.

Ozonation experiments were carried out under continuous operation in a bubble column. The effect of several parameters (inlet dye concentration, applied ozone dose, pH and conductivity) in colour and TOC removal of an acid dye solution was investigated with the aim to optimize the operation conditions. The ozone consumption was measured in each experiment.