OBJECTIVE To determine the association between KOH-soluble and structurally bound fluoride uptake and the erosion resistance of enamel, respectively. Additionally, the effect of enamel pre-treatment with ethanol before fluoridation was assessed. METHODS Sixty bovine incisors (4 specimens/tooth) were randomly allocated to six groups (A-F). Samples 1 and 2 remained untreated, serving as control...

Pyrolysis chars derived from rice wastes were chemically activated and used in W(VI) oxyanion adsorption assays synthetic mining wastewaters. For comparison purposes, a commercial carbon (CAC) was also used. Different experimental conditions tested the assays: solid/liquid ratio (S/L), initial pH, contact time, W concentration. The porous P2C+KOH presented overall best performance both media, d...

Two-dimensional (2D) porous carbon AC-SPN-3 possessing of amazing high micropore volume ratio of 83% and large surface area of about 1069 m(2) g(-1) is high-yield obtained by pyrolysis of natural waste Pistachio nutshells with KOH activation. The AC-SPN-3 has a curved 2D lamellar morphology with the thickness of each slice about 200 nm. The porous carbon is consists of highly interconnected uni...

Carvões ativados (CA) são caracterizados por elevadas áreas superficiais específicas e elevados volumes de poros. Os principais processos de obtenção destes materiais consistem na ativação de precursores com elevado teor de carbono, como por exemplo, o coque de petróleo (CP). Neste trabalho CP foi ativado quimicamente com hidróxido de potássio (KOH). O produto foi caracterizado por meio de adso...

We report the surprising chemiluminescence (CL) behavior of fluorescent carbon dots in the presence of a strong alkaline solution, such as NaOH or KOH. The CL intensity was dependent on the concentration of the base and carbon dots in a certain range. A possible CL mechanism was studied by UV-Vis, fluorescence, CL, FTIR, XPS and EPR spectroscopy. Radiative recombination of the injected electron...

The work is devoted to the study of physicochemical and surface-active properties N-(benzoyl)-N'-(phenylsulfonyl)hydrazine (BPSH) assess possibility using reagent in processes concentration non-ferrous metal ions. solubility ethanol, 0.1 mol/l KOH solution, toluene, chloroform, hexane was studied by spectrophotometry, refractometry, gravimetry. Acid-base equilibria solutions hydrolytic stabilit...

Interfacial behavior of hydroxide ions has been investigated by means of molecular dynamics simulations of aqueous KOH solutions between hydrophobic carbon-like walls. In agreement with previous calculations we show that a rigid, attractive wall strongly structures water molecules in neighboring hydration layers, leading to a concentration peak of hydrated OH ions located at about 5 Å from the ...

The formation process of self-assembled monolayer (SAM) of decanethiol (C10SH) on Au(111) single crystal electrode has been investigated for wide range of C10SH concentration (0.1 M ∼ 500 M) and temperature (253 K ∼ 298 K). The amount and quality of C10SH SAM were determined from area and position, respectively, of reductive desorption peak of the SAM modified Au(111) electrode measured in 0....