Evaluation of viscosity in binary mixtures of dimethyl sulphoxide at 298.15K

The viscosity of binary mixtures of dimethyl sulphoxide with different alcohols such as methanol, ethanol, 1-propanol, iso-propanol, 1-butanol, iso-butanol, tertiary butanol has been determined at 298.15K. The experimental values are compared with theoretical values evaluated by different theories. It is observed that for some theories, values are in agreement with the experimental values. Further, an attempt has been made to study the intermolecular interactions in studied solutions in terms of excess free energy of mixing, strength of interaction parameters and interaction energy. The viscosity data of pure liquids and their mixtures are needed to design various chemical processes where heat and mass transfer are important.

Removal of Phenol From Wastewater by High-Gravity Intensified Heterogeneous Catalytic Ozonation With Activated Carbon

In this study, the high-gravity technique is used to intensify the heterogeneous catalytic ozonation with activated carbon (AC) as the catalyst for removal of phenol from wastewater in a rotating packed bed (RPB), and the effects of high-gravity factor, inlet O3 concentration, liquid-gas ratio and initial pH on the degradation and mineralization of phenol at room temperature are investigated. It is revealed that the degradation rate of phenol reaches 100% at 10 min and the removal rate of total organic carbon (TOC) reaches 91% at 40 min under the conditions of high-gravity factor β=40, inlet O3 concentration =90 mg·L-1, liquid flow rate =80 L·h-1 and initial pH=11. Compared with the bubbling reactor (BR)/O3/AC and RPB/O3 systems, the mineralization rate of phenol by the RPB/O3/AC system is increased by 24.78% and 34.77%, respectively. Free radical quenching experiments are performed using tertiary butanol (TBA) and benzoquinone(BQ) as scavengers of ·OH and O2·−, respectively. It is shown that the degradation and mineralization of phenol are respectively attributed to the direct ozonation and the indirect oxidation by ·OH generated from the decomposition of O3 adsorbed on AC surface. •OH and O2•− are also detected by electron paramagnetic resonance (EPR). Thus, it is concluded that AC-catalyzed ozonation and high gravity technique had a synergistic effect on •OH initiation, which in turn can significantly improve the degradation and mineralization of organic wastewater.

A series of lanthanide–quinoxaline-2,3(1H,4H)-dione complexes containing 1D chiral Ln2O3 (Ln = Eu, Tb, Sm, Dy) chains: luminescent properties and response to small molecules

A series of isostructural lanthanide–quinoxaline-2,3(1H,4H)-dione containing 1D chiral chains shows high sensing effect toward the small solvent molecules, in which tertiary butanol was an excellent sensitizer, while tetrahydrofuran was a highly quenching species.

Crystallisation temperature control of stoichiometry and selectivity in host–guest compounds

A bulky diol host is only selective for tertiary butanol when versus 2-propanol at low temperatures.

Morphology of the Dentin–resin Interface yielded by Two-step Etch-and-rinse Adhesives with Different Solvents

ABSTRACT Aim The study aimed to analyze the morphology of the dentin–resin interface yielded by two-step etch-and-rinse adhesive systems with different solvents and compositions. Materials and methods A total of 32 dentine disks were prepared and randomly assigned to four groups of one-bottle etchand-rinse adhesive systems containing different solvents: group I, Adper Scotchbond-1XT™ (ethanol/water); group II, XP-Bond™ (tertiary butanol); group III, Prime and Bond NT® (acetone); and group IV, One Coat bond® (5% water). Adhesive systems were applied onto dentin disks, which were then thermal cycled, divided into two hemi-disks (n = 16), and prepared for field-emission scanning electron microscopy to examine the dentin–resin interdiffusion zone. Microphotographs were scanned and data were processed. Data were compared with analysis of variance multivariant test after Kolmogorov–Smirnov and Shapiro–Wilk tests using Statistic Package for the Social Sciences. Results The adhesive layer thickness average found was group I: 45.9 ± 13.41 μm, group II: 20.6 ± 16.32 μm, group III: 17.7 ± 11.75 μm, and group IV: 50.7 ± 27.81 μm. Significant differences were found between groups I and IV and groups II and III (p<0.000). Groups I (3.23 ± 0.53 μm) and II (3.13 ± 0.73 μm) yielded significantly thicker hybrid layers than groups III (2.53 ± 0.50 μm) and IV (1.84 ± 0.27 μm) (p<0.003). Group III presented a less homogeneous hybrid layer, with some gaps. Tag length average was greater in groups II (111.0 ± 36.92 μm) and IV (128.9 ± 78.38 μm) than in groups I (61.5 ± 18.10 μm) and III (68.6 ± 15.84 μm) (p<0.008). Conclusion Adhesives systems with different solvents led to significant differences in the dentin–resin interface morphology. Solvents role in adhesives bond strength should be considered together with the other adhesive system components. Clinical significance The adhesive containing tertiary butanol, in addition, seems to originate a good-quality hybrid layer and long, entangled tags and also appears to have greater ability to originate microtags, which may indicate higher bond strength. How to cite this article Ferreira JC, Pires PT, de Azevedo ÁF, Arantes-Oliveira S, Silva MJ, de Melo PR. Morphology of the Dentin–resin Interface yielded by Two-step Etch-and-rinse Adhesives with Different Solvents. J Contemp Dent Pract 2017;18(10):947-958.

tert-Butylation of naphthalene by tertiary butanol over HY zeolite and cerium-modified HY catalysts

Cerium-modified HY catalysts exhibit a high 2,6-/2,7-DTBN ratio in naphthalene tert-butylation due to the weakened acid strength.

Evaluation of Biocompatibility of an Etch-and-Rinse Adhesive System Based in Tertiary Butanol Applied in Deep Cavity

The aim of this study was to evaluate biocompatibility of an etch-and-rinse adhesive system based in tertiary butanol applied in deep cavity human teeth with approximately 1 mm of remaining dentin by observing histological changes of the pulp tissue of humans at intervals of 01, 07, 14 and 21 days. Twenty third molars with indication for xtraction from patients of both sexes, presenting no systemic alterations were used. Class I cavity was made deeper and then, XP BOND adhesive system and resin Filtek Z250 were applied. The sample was divided into four groups according to the time intervals between the application of adhesive system and extraction. Morphologic criteria analysed considered the presence of hyperemia, type of inflammatory cell response, organization of odontoblast cells layer, organization of pulp tissue and the presence or absence of bacteria. Data were submitted to Fisher Exact Test p> 0.05. We observed mild inflammatory infiltrate, preserved pulp tissue morphology, disorganization of the odontoblast layer in most specimens, as well as absence of bacteria at the intervals of 01, 07, 14 and 21 days. In some cases there was pulp hyperemia. The etchand- rinse adhesive system based in tertiary butanol showed satisfactory behavior in the conditions studied.