Perforated cenosphere-supported pH-sensitive spin probes

Abstract

Porous supports with an accessible internal volume and a shell providing the diffusive migration of pH sensitive spin probes were obtained for the first time from hollow aluminosilicate cenospheres isolated from the coal fly ash. Using the methods of scanning electron microscopy and electron spin resonance, the morphology of different porous cenosphere modifications and its influence on the diffusion of spin probes from the internal volume were studied. When supporting aqueous solutions of a radical, the characteristic diffusion time for the mesoporous structure of the support is longer by a factor of 3-5 than that for the macroporous structure. Ferrospinel in a content of 6 wt.% do not virtually affect the diffusion rate of spin probes. A constant rate of radical migration of 1 μmol min -1 , determined by radical solubility in water, is achieved when a radical in the solid aggregate state is supported on the magnetic cenospheres.

Integrating phase change materials into concrete through microencapsulation using cenospheres

“…introduce PCM into cenospheres, the film covering the surface must be removed. This can be done by acid etching the cenospheres [21,22]. was quickly removed from the hot plate for cenospheres to be filtered and washed by °C water.…”

“…The specific gravity of cenospheres used is about 0.75 g/cm3 , thus 12 g of cenospheres corresponded to a volume of 16 mL. This made the volume ratio of solid to liquid to 1:15 in this acid treatment, which was among the range adopted by other researchers[21,22]. Occasional stirring was applied instead of continuous one to prevent the possible damage of the cenospheres during stirring.…”

“…The mortar samples were prized into pieces for SEM observation as well. This is because alumina was not subjected to the etching action[21], while the silica and iron deposits on cenospheres were dissolved by the hydrofluoric based acid system.The dissolution resulted in about 8.77% weight loss of the cenospheres shell. This small amount of dissolution indicates that the acid etching is able to perforate the shell without compromising…”

Hydrothermal Co-Processing of Coal Fly Ash Cenospheres and Soluble Sr(II) as Environmentally Sustainable Approach to Sr-90 Immobilization in a Mineral-like Form

“…), composition and globule structure. At present, the fine classification of cenospheres was realized [ 28 , 29 , 30 ], resulting in cenosphere fractions of the specific chemical, phase and granulometric composition with predictable high-tech properties [ 31 , 32 , 33 , 34 ].…”

Characterization of Aerodynamically Separated Products of Fly Ash Produced via the Pulverized Combustion of Coal from Kuznetsk Basin

“…В последние годы повышенный интерес вызывают разработки на основе отдельных компонентов зол функциональных материалов с заданными свойствами (адсорбентов, катализаторов, носителей, керамических материалов, цеолитов) [4,6]. Так, вы-деление из зол-уноса узких фракций микросфер определенного размера в интервале 50-250 мкм с постоянным химическим и минерально-фазовым составом [18][19][20][21] позволило получить высокоселективные мембраны для диффузионного выделения гелия и контейнеры для хра-нения водорода [22][23][24], эффективные катализаторы для процессов окисления метана [25,26], крекинга тяжелой нефти, мазутов и битумов [27,28], сенсибилизаторы эмульсионных взрывча-тых веществ [29], магнитоуправляемые капсулированные рН-чувствительные спиновые зонды для исследования биологических объектов [30], магнитные аффинные сорбенты типа «ядро-оболочка» для выделения рекомбинантных белков [31,32], композитные сорбенты для извле-чения радионуклидов из жидких радиоактивных отходов [33][34][35].…”