Development of regenerative dye impregnated mesoporous silica materials for assessing exposure to ammonia

Abstract

The mesostructured materials MCM-41 and SBA-15 were studied as possible supports of bromocresol green (BG) dye impregnation for the ammonia gas detection because of their large surface area, high regenerative property, and high thermal stability. X-ray diffraction, transmission electron microscopy, scanning electron microscope, and N 2 adsorption analysis were used to characterize the prepared materials. These materials could sense ammonia via visible color change from yellowish-orange to blue color. The color change process of the nanostructured materials was fully reversible during 10 cyclic tests. The results indicated that the ammonia absorption responses of the two nanostructured materials were both very sensitive, and high linear correlation and high precision were achieved. As the gaseous ammonia concentrations were 50 and 5 ppmv, the response times for the SBA-15/BG were only 1 and 5 min, respectively. Moreover, the BG dye-impregnated SBA-15 was less affected by the variation in the relative humidity. It also had faster response for the detection of NH 3 , as well as lower manufacturing price as compared to that of the dyeimpregnated MCM-41. Such feature enables SBA-15/BG to be a very promising material for the detection of ammonia gas. Implications:The detector tube is a convenient ambient ammonia detection device. However, almost all the commercial detector tubes can be used once only, which not only increases the purchase cost but also produces lots of waste. In this study, we developed two sensing materials that are sensitive for repeated usage. The two mesoporous silica-based materials, MCM-41 and SBA-15, are impregnated by an organic dye of bromocresol green to induce color change behavior that can be easily observed by the naked eye, and it is concluded that dye-impregnated SBA-15/BG is a very promising material for the detection of ammonia gas.

Development of Thiabendazole-Loaded Mesoporous Silica Nanoparticles for Cancer Therapy

“…The resulting isotherms were type IV according to the International Union of Pure and Applied Chemistry (IUPAC) classification, and the N 2 uptake, caused by capillary condensation, was observed at relative pressure ( p / p 0 ) range of 0.22–0.35 for both formulations. These types of isotherms are related to mesoporous materials . Also, both isotherms formed H1 hysteresis loops at intermediate relative pressures, thus indicating the formation of well-shaped pores with a hexagonal geometry.…”

“…These types of isotherms are related to mesoporous materials. 39 Also, both isotherms formed H1 hysteresis loops at intermediate relative pressures, thus indicating the formation of well-shaped pores with a hexagonal geometry. Isotherms with similar shapes also indicate similar pore size.…”

Synthesis of High Valence Silver-Loaded Mesoporous Silica with Strong Antibacterial Properties

“…SBA-15 is one of the most widely used mesoporous silica materials because of its large surface area and uniform pore structure [ 31 , 32 , 33 ], which can be modified with functional groups to tailor their properties and achieve specific purposes [ 33 , 34 , 35 ]. Thus, the development of functionalized SBA-15 as hosts for high valence Ag is interesting and promising.…”