Biologically active properties of plant extracts in cosmetic emulsions

Describes biologically active properties waters plant extracts of domestic herbaceous species as a part cosmetic emulsion in this article. In particular, the antioxidant features related to vitamins, flavonoids, coloring, extractive and tannins were reported. The following research methods as qualitative analysis on groups of biologically active substances, thin-layer chromatography, titrimetry and photometry were used in the work. The ability of extracts to influence the physico-chemical, organoleptic and antioxidant properties of cosmetic emulsion samples was established. The ability of the extracts to exhibit antioxidant and prooxidant effects in cosmetic emulsion samples was determined. This article represents a contribute in the identification of plant extracts and their use as biologically active additives in cosmetic emulsion

Sustainable nanocomposites based on halloysite nanotubes and pectin/polyethylene glycol blend

This study was focused on the preparation and characterization of biofilms based on pectin/polyethylene glycol 20000 (PEG) blend and halloysite nanotubes (HNTs). The obtained blends loaded with a natural nanoclay are proposed as sustainable alternative to the polymers produced from non-renewable resources such as fossil fuels. Properties of technological interest have been monitored and they were correlated to the structural features of the nanocomposites. It turned out that the wettability of the films can be tuned by changing the composition and the distribution of HNTs into the material as well as the surface roughness. The tensile properties of the blend are enhanced by the presence of the nanoclays. The PEG crystallinity is reduced by the nanoparticles and preserved if a certain amount of pectin is added. This work represents a starting point to develop new green composite material, which can be used for purposes such as in packaging, by employing the strategy of adding plasticizers and fillers within a full biocompatible approach

Dispersions of Nanoclays of Different Shapes into Aqueous and Solid Biopolymeric Matrices. Extended Physicochemical Study

Dispersions of nanofillers into aqueous and solid biopolymeric matrices were studied from the physicochemical viewpoint. This work was carried out based on the idea that the combination of biopolymers, derived from renewable resources, and nanofiller, environmentally friendly, may form a new generation of nanomaterials with excellent and unique properties at low cost. To this purpose, two pectins with different degrees of methyl esterification and nanoclays like halloysite and laponite RD were selected. The thermodynamic and structural studies on the aqueous mixtures of pectin and nanoclay were able to discriminate the interactions, which control the adsorption of pectin onto the filler and the aggregation of both pectin and clay particles. The gained insights were useful to interpret the mesoscopic structure of the nanocomposites (prepared from the aqueous mixtures by means of the casting method) evidenced by SEM, thermal stability, tensile properties, and transparency investigations. The attained knowledge represents a basic point for designing new hybrid nanostructures in both the aqueous and the solid phase for specific purposes

Copolymer−Cyclodextrin Inclusion Complexes in Water and in the Solid State. A Physico-Chemical Study

The formation of inclusion complexes (ICs) composed of cyclodextrins (CDs) and poly(ethylene oxides)-poly(propylene oxides)-poly(ethylene oxides) (PEO-PPO-PEO) was studied. To this purpose, native and hydroxypropyl cyclodextrins with different cavity size were chosen. The PEO-PPO-PEO copolymers were selected to study the role of the molecular weight, keeping constant the hydrophilic/ hydrophobic ratio, and the hydrophilicity. The volumetric studies at 25 °C allowed to determine the equilibrium constant and the volume change for the IC formation in water as well as the IC stoichiometry. Surface tension experiments evidenced that the copolymer and the CD interfacial behavior is controlled by the formation of ICs taking place in the bulk phase. It was proved that the differential scanning calorimetry (DSC) is a valid method to describe quantitatively the IC in the solid state. The combination of volumes, DSC and FTIR techniques together with the geometric information highlighted the following points: (1) the included copolymer is in the amorphous state; (2) the IC composed of native CDs adopts a channel structure with two EO units incorporated into one CD molecule; (3) the IC composed of hydroxypropyl-cyclodextrin is a polymeric structure like a necklace decorated with CD rings. Finally, TGA experiments showed that the thermal stability of the IC depends on the nature of both components

Halloysite nanotubes: a green resource for materials and life sciences

Clay minerals are considered one of the materials of the 20th century for their peculiar physico-chemical features. Among them, halloysite nanotubes (HNTs) are an emerging nanomaterial with a particular tubular structure that makes them a low cost and valuable alternative to the most common carbon nanotubes. Due to their tubular morphology, HNTs are employed in several fields acting as nanocontainers for different compounds for applications in drug carrier and delivery fields, catalysis, and as filler for polymeric matrices. The modification of HNTs’ surfaces allows to the synthesis of different nanoarchitectures that can improve the mechanical and thermal performance of polymer as well as they can enhance the use for the loading and release of chemicals. In this review, we summarize our recent results on halloysite functionalization, both supramolecular and covalent, and the application aforementioned fields