Customising Sustainable Bio-Based Polyelectrolytes: Introduction of Charged and Hydrophobic Groups in Cellulose.

Cellulose has been widely explored as a sustainable alternative to synthetic polymers in industrial applications, thanks to its advantageous properties. The introduction of chemical modifications on cellulose structure, focusing on cationic and hydrophobic modifications, can enhance its functionality and expand the range of applications. In the present work, cationization was carried out through a two-step process involving sodium periodate oxidation followed by a reaction with the Girard T reagent, yielding a degree of substitution for cationic groups (DS) between 0.

Lignin extraction from acacia wood: Crafting deep eutectic solvents with a systematic D-optimal mixture-process experimental design.

Lignin is a complex biopolymer whose efficient extraction from biomass is crucial for various applications. Deep eutectic solvents (DES), particularly natural-origin DES (NADES), have emerged as promising systems for lignin fractionation and separation from other biomass components. While ternary DES offer enhanced fractionation performance, the role of each component in these mixtures remains unclear.

Rheology of Suspensions of TEMPO-Oxidised and Cationic Cellulose Nanofibrils-The Effect of Chemical Pre-Treatment.

Cellulose nanofibrils (CNFs) are particles with a high aspect ratio. Typically, chemically pre-treated CNFs (containing anionic or cationic charged groups) consist of long fibrils (up to 2 μm) with very low thickness (less than 10 nm). Derived from their high aspect ratio, CNFs form strong hydrogels with high elasticity at low concentrations.

Influence of dispersion of fibrillated cellulose on the reinforcement of coated papers.

The use of cellulose micro/nanofibrils (CMNFs) as reinforcement paper additive at industrial scale is delayed due to inconsistent results, suggesting a lack of proper consideration of some key parameters. The high influence of fibrillated nanocellulose dispersion has been recently identified as a key parameter for paper bulk reinforcement but it has not been studied for surface coating applications yet. This paper studies the effect of CMNF dispersion degree prior to their addition and during mixing with starch on the reinforcement of paper by coating.

Isolation of Extracellular Vesicles from Human Follicular Fluid: Size-Exclusion Chromatography versus Ultracentrifugation.

Follicular fluid (FF) is the microenvironment where a growing oocyte develops. Intrafollicular communication ensures oocyte competence and is carried out through paracrine signaling, the exchange of molecules via gap junctions, and the trafficking of extracellular vesicles (EVs). The study of FF-derived EVs is important for both translational and fundamental research in the female reproductive field.

On Hair Care Physicochemistry: From Structure and Degradation to Novel Biobased Conditioning Agents.

Hair is constantly exposed to various adverse external stimuli, such as mechanical or thermal factors, that may cause damage or cause it to lose its shine and smooth appearance. These undesirable effects can be minimized by using hair conditioners, which repair the hair and restore the smooth effect desired by the consumer. Some of the currently used conditioning agents present low biodegradability and high toxicity to aquatic organisms.

Heavy Metals Removal from Aqueous Solutions by Multiwall Carbon Nanotubes: Effect of MWCNTs Dispersion.

Carbon nanotubes (CNTs) are one of the most studied nanoparticles due to their physical, chemical and electronic properties. However, strong Van der Waals bonds, which promote CNTs aggregation are usually present, affecting their unique properties. Avoiding CNTs aggregation is one of the main difficulties when using these nanoparticles.

Characterization of Two Cactus Formulation-Based Flocculants and Investigation on Their Flocculating Ability for Cationic and Anionic Dyes Removal.

Dye invasion in wastewaters is undeniably one of the crucial environmental concerns in addition to the supplement of toxic synthetic chemical flocculants used for color removal using the conventional coagulation-flocculation process. With the aim to improve the flocculation stage in terms of reagents safety and ensure dyes removal, the present study explores the flocculating effectiveness of two natural, stable, and eco-friendly cactus formulations, namely 60 °C oven-dried (DP) and lyophilized (LP) cladodes. Both formulations were assessed to treat cationic (Methylene blue; MB) and anionic (Methyl Orange; MO) dye solutions as a substitution attempt for the currently questioned employed synthetic chemical flocculants.

The critical role of the dispersant agents in the preparation and ecotoxicity of nanomaterial suspensions.

This work reports the role of different dispersants, namely, polyethylene glycol (PEG 200 2%), ethylene glycol 5%, ethanol 2%, dimethyl sulfoxide (DMSO 5%), and polyvinyl alcohol (PVA 5%) in the toxicity profile of several commercial nanomaterials (NM), such as hydrophilic and hydrophobic TiO, hydrophilic SiO, SiO in aqueous suspension (aq), and ZnO towards the bioluminescent bacterium Aliivibrio fischeri. The majority of NM showed tendency to form agglomerates in the different dispersants. Although some particle agglomeration could be detected, DMSO at 5% was the best dispersant for hydrophobic TiO NM while PVA at 5% was the most effective dispersant for the other types of NM.

Is the aquatic toxicity of cationic polyelectrolytes predictable from selected physical properties?

Cationic acrylamide-based polyelectrolytes (cPAM) are widely used in industry. They can be designed for optimal performance in a specific application, but this opportunity means the environmental safety of all different alternatives needs to be addressed. Both the inclusion of environmental toxicity as a design variable and the establishment of relationships between structure and ecotoxicity are thus current challenges.

Influence of the stabilizers on the toxicity of metallic nanomaterials in aquatic organisms and human cell lines.

In this study, following a systematic approach, we used aquatic species (bacteria Vibrio fischeri and microalgae Raphidocelis subcapitata) and different human cell lines (Caco-2, HepG2, SV-80 and HaCaT) representing different tissues and exposure pathways, to investigate how two organic stabilizers (PVA and DMSO) used for NMs dispersion influence their physicochemical properties, the persistence of metals in suspension and the toxicity/ecotoxicity of two metallic NMs (nano-Ag and nano-Cu). Although the stabilizers are expected to contribute to improve the dispersion and stability of NMs, the results obtained clearly showed that no similar changes in toxicity and morphological properties of the nano-Ag can be expected after its stabilization with PVA. Thus, regarding human cell lines, the reduction in the average size of the PVA-nano-Ag was followed by a reduction or maintenance of its toxicity, but the opposite was observed for the aquatic species tested since an increase in the average size enhanced its toxicity.

Oxidative stress and genotoxicity of an organic and an inorganic nanomaterial to Eisenia andrei: SDS/DDAB nano-vesicles and titanium silicon oxide.

In the past few years the number of studies on the toxic effects of nanomaterials (NMs) in the environment increased significantly. Nonetheless, the data is still scarce, since there is a large number of NMs and new ones are being developed each day. Soils are extremely important for life, and are easily exposed to the released NMs, thus enhanced efforts are needed to study the impacts on soil biota.