OBJECTIVE The purpose of this study was to evaluate the effects of three different surface conditioning methods on the shear bond strength (SBS) of metal brackets bonded directly to gold alloy with chemically cured resin. METHODS Two hundred ten type III gold alloy specimens were randomly divided into six groups according to the combination of three different surface conditioning methods (alu...

In this study, chemical transformations of benzyl ester of О-(phenyl-2-acetamido-2,3-dideoxy-1-thio-β-d-glucopyranoside-3-yl)-d-lactoyl-l-alanyl-d-isoglutamine (SPhMDPOBn) on the fumed silica surface were examined, and the surface complex structure was characterized by temperature-programmed desorption mass spectrometry (TPD-MS), infrared spectroscopy (FTIR) and electrospray ion trap mass spect...

Silica-bonded n-propyltriethylene-tetramine (SBNPTT) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4H-chromenes. Chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oC under solvent-free conditions. The heterogeneous solid base showed much the same efficiency when u...

Silica-bonded N-propyldiethylenetriamine sulfamic acid (SPDTSA) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines  through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines  at room temperature under solvent-free conditions. SPDTSA showed much the same efficiency when used in con...

The one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by tandem Knoevenagel-Michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid catalyst was reported. SBPPSA showed much the same efficiency when used in consecutive reaction runs.

A chlorination method for the selective substitution of well-defined isolated silanol groups of the silica surface has been developed using the catalytic Appel reaction. Spectroscopic analysis, complemented by elemental microanalysis studies, reveals that a quantitative chlorination could be achieved with highly dehydroxylated silica materials that exclusively possess non-hydrogen bonded silano...

We developed room-temperature bonding of micro-nanofluidic device using fluorine induced plasma activation method. Fluorine was induced by O2 reactive ion etching (RIE) plasma treatment with Teflon Pieces which increased the bonding strength between fused silica glass substrates. The room-temperature bonded fused silica glass micro-nanofluidic device had high bonding strength as well as could w...

The one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols) by tandem Knoevenagel-Michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded N-propylpiperazine sulfamic acid (SBPPSA) as a recyclable solid acid catalyst was reported. SBPPSA showed much the same efficiency when used in consecutive reaction runs.

A novel Congo red (CR) derivatized silica stationary phase was prepared and packed into a fused silica capillary tube for nano-flow HPLC. A variety of analytes including poly-aromatic hydrocarbons, parabens, acids, sulfonamides, bases, and nucleosides were successfully separated using the CR. In comparison with commercial ODS columns, this new stationary phase has a different separation mechani...