conclusions changes of ph could remarkably affect the efficiency and oxidation rate of mtbe. in particular, the amount of kap in terms of oxidation declines substantially by moving away from the optimum ph range. in this study, ph 3.5 was considered as the optimal ph in h2o2/nzvi/ultrasonic oxidation process, with the elimination of about 89.56% of the high mtbe concentration. in general, we ca...

introduction: the aim of this study was to compare the chemical compounds of white proroot mineral trioxide aggregate (wmta) hydrated at different ph environments. methods and materials: mixed samples of wmta were kept in acidic (ph=5.4), neutral (ph=7.4) and alkaline (ph=9.4) environments for 48 h. then, x-ray diffraction (xrd) analysis was performed for both hydrated and powder forms of wmta....

hydrogels, due to their unique potentials such as high-water content and hydrophilicity are interest for the controlled release of drug molecules. the present study aims to create a controlled-release system through the preparation and characterization of hydrogels based on ph-sensitive polymers such as poly (acrylic acid). poly (acrylic acid), p(aa), hydrogel has been synthesized by radical po...

o bjectives: the purpose of this study was to evaluate the effect of salivary ph on the shear bond strength (sbs) of orthodontic brackets to tooth surface. materials and methods: eighty intact premolars were randomly divided into four groups of 20.  after bonding a bracket on each tooth, the groups one to four were stored in artificial saliva at a ph of 3.8, 4.8, 5.8, and 6.8, respectively for ...

objective(s) in this study, a kind of ph sensitive composite membrane was prepared and drug permeation through it was investigated in terms of ph. rationale of this study originated from the fact that a ph change which may be a result of a disease state in the body can trigger drug release. materials and methods  here, a kind of ph sensitive composite membrane containing different nanoparticle ...