Search results for " Emulsion"
showing 10 items of 54 documents
Biologically active properties of plant extracts in cosmetic emulsions
2020
Abstract 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 de…
Halloysite based geopolymers filled with wax microparticles as sustainable building materials with enhanced thermo-mechanical performances
2022
This work proposes a novel protocol for the fabrication of halloysite based geopolymers filled with beeswax microparticles obtained from Pickering emulsions. The actual filling of the microwax into the geopolymers has been demonstrated by using several techniques, including thermal analyses, spectroscopies, microscopies and contact angle experiments. According to the morphological and structural investigations, microwax spherical particles (diameter ranging between ca. 3 and 5 μm) have been homogeneously dispersed within the geopolymeric network conferring excellent properties to the hybrid geopolymers in terms of mechanical performances and heat storage capacity although their low content …
Pickering Emulsions Stabilized by Halloysite Nanotubes: From General Aspects to Technological Applications
2022
Besides surfactants, which decrease the interfacial tension between two immiscible liquids, also interfacially active particles can successfully stabilize an emulsion system by attaching at the liquid–liquid interface. The preparation of the resulting Pickering emulsions has been so far investigated starting from the study of the interactions arising between the dispersed droplets and the stabilizers, till the application of these systems in a wide range of different fields. This work is intended to provide an overall overview about the development of Pickering emulsions by considering the most general aspects and scanning the diverse types of solid stabilizers. Among them, Halloysite nanot…
Synthesis and characterisation of a ternary composite of polyaniline, reduced graphene-oxide and chitosan with reduced optical band gap and stable aq…
2019
A ternary composite comprising of p-toluene sulfonic acid doped polyaniline (PANI), chitosan and reduced graphene oxide (RGO) with stable aqueous dispersibility has been synthesised via oxidative polymerisation of aniline in chitosan/RGO dispersion. For comparison; PANI, PANI/chitosan and PANI/RGO composites were also synthesised using the same procedure. FTIR, Raman, XPS, XRD and UV-VIS confirmed the successful synthesis of the PANI and the composites. The aqueous dispersions of the PANI/chitosan and the ternary composites were found to be stable even after more than four months. The stability of the dispersion was attributed to the polycationic nature of the chitosan. The thermogravimetri…
Development of accurate mass spectrometric routine and reference methods for the determination of trace amounts of iridium and rhodium in photographi…
1999
For the determination of trace amounts of iridium and rhodium in photographic emulsions different sample treatment procedures were coupled with inductively coupled plasma mass spectrometry (ICP-MS) and, for iridium, also with negative thermal ionisation isotope dilution mass spectrometry (NTI-IDMS) and ICP-IDMS. IDMS determinations of iridium were carried out using an enriched 191Ir spike solution. Elimination of the silver matrix was established for both mass spectrometric methods, which prevents corresponding memory effects in the ICP-MS system and is essential for the formation of IrO2 - thermal ions, respectively. For NTI-MS measurements, the gelatine matrix of the emulsion must also be…
Emulsions based on fatty acid from vegetable oils for cosmetics
2022
Vegetable oils are sources of saturated, monounsaturated and polyunsaturated fatty acids. In this work, we studied the suitability of a mixture of vegetable oils and some fatty acids (similar to the those of the human skin) as a cosmetic emulsion. Hypericum (Hypericum perforatum L.) – 1 %, thistle (Silybum marianum (L.) Gaertn.) – 42 %, linen (Línum usitatíssimum L.) – 1.1 %, wheat germ (Triticum aestivum L.) – 1 %, sesame (Sésamum índicum L.) – 1 %, mustard (Sinápis álba L.) – 2%, pumpkin (Cucúrbita p é po L.) – 5 %, – were selected as vegetable oils. The emulsion based on the proposed mixture of vegetable oils has a higher antioxidant activity (1.623 OD) compared with that based on minera…
Hydroxypropyl Cellulose Films Filled with Halloysite Nanotubes/Wax Hybrid Microspheres
2021
The design of novel nanocomposite films based on hydroxypropyl cellulose (HPC) and wax/halloysite hybrid microspheres has been reported. In particular, we first prepared wax/clay Pickering emulsions which were characterized by thermogravimetric analysis and microscopy. SEM images allowed more detailed insights on the nanotubes disposition at the wax/water interface, acting as an outer stabilizing shell. Therefore, the cellulosic biopolymer was added, and it was found that HPC enhances the colloidal stability of the particles, preventing their coalescence and sedimentation. The preparation of the composite films was carried out by the solvent casting method, which enabled the development of …
Surface active and emulsifying properties of casein micelles compared to those of sodium caseinate
1999
Emulsions prepared using casein micelles and sodium caseinate as the emulsifying agent are compared. It is found that the ultrastructure of the casein proteins influences the properties of the emulsion.
High pressure processing of food-grade emulsion systems: Antimicrobial activity, and effect on the physicochemical properties
2019
Abstract The use of high pressure processing (HPP) for development of stable emulsion-based delivery systems has been recently increased. Under adequate conditions, application of high pressures modifies the functionality of protein and polysaccharide molecules and significantly promotes the emulsifying activities. Application of high pressures also modulates the emulsion microstructure without any destabilization and gelation of protein molecules. The lipid oxidation in HPP-treated emulsions can be accelerated, particularly with higher pressure levels, while the HPP utilization on emulsions in acidic conditions can highly inhibit the growth of spoilage and pathogenic microorganisms. In thi…
Magnetically enhanced polymer-supported ceria nanocatalysts for the hydration of nitriles.
2020
The heterogeneous catalysis of the hydration of nitriles to amides is a process of great industrial relevance in which cerium(IV) oxide (also referred to as ceria) has shown an outstanding catalytic performance. The use of non-supported ceria nanoparticles is related to difficulties in the purification of the product and the recovery and recyclability of the catalyst. Therefore, in this work, ceria nanoparticles are supported on a polymer matrix either by synthesizing polymer particles by so-called Pickering miniemulsions while using ceria nanoparticles as emulsion stabilizers or, as a comparison, by in-situ crystallization on preformed polymer particles. The former strategy presents signif…