A New System of Multiple Emulsions with Lamellar Gel Phases from Vegetable Oil

Emulsions are excellent pharmaceutical vehicles used in both the pharmacy and cosmetic industries. Vegetable oils have several effects/benefits on skin and can be used in emulsions to release principal active components for cosmetic purposes. Herein, multiple W/O/W emulsions were formulated in a one-step emulsification method, and the resulting anisotropic structures were characterized by x-ray diffraction measurements. The multiple emulsions obtained were stable and maintained their anisotropic structures over 2 years. WAXS (wide-angle x-ray scattering) measurements of these emulsions suggested that the carbon chains of the surfactant around the globules are disposed in a gel network phase. Furthermore, SAXS (small-angle x-ray scattering) measurements indicated that the surfactant is organized in lamellar layers around the globules. Thus, for the first time, we demonstrated that stable lamellar gel phase multiple emulsions can be made from vegetable oils. In addition to having the advantage of being prepared in one step, these emulsions have desirable characteristics that can be used in the cosmetic industry as natural active principles with low surfactant concentration and the unique features of multiple emulsions with gel phases.     

Removal of fluoride from aqueous solution using acid and thermally treated bone char

In this work, bone char (BC) was synthesized at different calcination temperatures and modified by using HNO₃ solutions having distinct concentrations. Furthermore, the relationship between the crystalline structure and physicochemical properties of BC on the adsorption capacity of BC towards fluoride from aqueous solution was analyzed. It was noted that the calcination temperature and the acid modification of BC significantly influenced the crystalline phases, crystallite size, and contents of hydroxyapatite, monetite, and other calcium phosphates, which are the main constituents of the BC. Additionally, the surface area diminished by raising both the calcination temperature and acid concentration used in the modification. The adsorption capacity of BC linearly declined as the calcination temperature was increased from 400 to 800 °C. On the other hand, BC modified with HNO₃ solutions showed that the adsorption capacity of BC was enhanced when monetite and hydroxyapatite with low crystallinity were present in these materials. Hence, the adsorption capacity of BC treated with acid was independent of textural properties. The adsorption capacity of BC was enhanced by increasing the solution pH due to the electrostatic interactions between the fluoride in the solution and the surface charge of BC. Finally, DRX, FTIR spectroscopy, and XPS studies corroborated that the fluoride adsorption mechanism on BC modified with acid solutions was influenced by electrostatic interactions and chemisorption between fluoride ions in solution and calcium phosphates from hydroxyapatite and monetite.     

Unmixedness of some weighted oriented graphs

Journal of Algebraic Combinatorics - Let $$D=(G,\mathcal {O},w)$$ be a weighted oriented graph whose edge ideal is I(D). In this paper, we characterize the unmixed property of I(D) for each one of...     

A Characterisation of Morita Algebras in Terms of Covers

Algebras and Representation Theory - A pair (A, P) is called a cover of EndA(P)op if the Schur functor HomA(P,?) is fully faithful on the full subcategory of projective A-modules, for a given...     

Characterization of the visible-light-driven BiVO4 photocatalyst synthesized via a polymer-assisted hydrothermal method

BiVO₄ photocatalyst was synthesized by a polymer-assisted hydrothermal method at different temperatures and reaction times. Sodium carboxymethylcellulose was used in order to assist the formation of BiVO₄ oxide. The resulting samples were characterized by X-ray powder diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, and adsorption–desorption N₂ isotherms (BET). The predominant BiVO₄ phase of the system within the 160–200 °C range was the monoclinic crystalline structure, which was obtained in pure form only under certain experimental conditions. Short reaction times promoted the formation of linear arrays of BiVO₄ formed by particles with irregular form ranging in size between 100 and 200 nm. The photocatalytic activity of BiVO₄ samples was evaluated in the degradation of rhodamine B (rhB) under visible-light irradiation. The samples exhibited a higher activity when they were synthesized at higher temperatures and longer times of hydrothermal reaction. The total organic carbon analysis of a sample irradiated for 100 h revealed that mineralization of rhB by the BiVO₄ photocatalyst is feasible.