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ZnO nanoparticles are uniformly coated on the walls of carbon nanotubes (CNTs) via a straightforward process, and the particle size and interparticle distance can be controlled by coating time. The appropriate amount of coated nanoparticles effectively reduces the formation of various structural defects induced by oxygen or hydrogen atoms on the walls of CNTs, which can be evaluated through a decrease in the intensity ratio of disorder graphitic band (D peak) over graphitic C-C stretching band (G peak) in the Raman spectrum. An overincrease in coating time simultaneously causes an increase in interstitial zinc and oxygen vacancies in ZnO. The high local electric field around the ZnO particle on the walls of CNTs can increase the tunneling probability at CNTs-ZnO heterojunction, significantly enhancing the field emission property for CNTs.

The type of tissue conditioner, and especially immersion time, had a significant effect on the surface quality of dental stone casts. The type of dental stone used is less important.

The purpose of this study was to determine the effect of PMMA polymer on dynamic viscoelasticity and plasticizer leachability of PEMA-based tissue conditioners. One PEMA polymer and one PMMA polymer were used in powder form with four formulations. The combination of 80 wt% ATBC, 15 wt% BPBG and 5 wt% ethyl alcohol was used as the liquid phase. The dynamic viscoelasticity and plasticizer leaching of each specimen were measured after 0, 1, 3, 7, and 14 days of immersion (37°C distilled water) using DMA and HPLC. A significant difference was found among the materials in the dynamic viscoelasticity and leaching of plasticizer. The materials containing 10 wt% PMMA showed the most stable dynamic viscoelasticity, and showed the lowest leaching of plasticizer. The results suggest that the addition of the PMMA polymer to the powder of a tissue conditioner can improve the durability of the PEMA-based tissue conditioner.