Tunable synthesis of dendritic fibrous nano silica using 1-pentanol-water microemulsion at low oil to water ratio

Abstract

Dendritic fibrous nanosilica (DFNS) is a suitable nano-carrier for loading pesticides with radially oriented pores and a large surface area. The microemulsion method is standard method to prepare DFNS, and 1-pentanol is taken to replace cyclohexane as an oil solvent due to its high stability and nontoxic property. The results showed that the volume ratio of 1-pentanol (oil) to water (O/W) and the molar ratio of hexadecyltrimethylammonium bromide (CTAB) to tetraethylorthosilicate (TEOS) had effected on morphology and adsorption properties of DFNS in the water-CTAB-1-pentanol-ethanol-trimethylbenzene (TMB) microemulsion system. DFNS with bicontinuous concentric lamellar morphologies can be synthesized in this microemulsion at the meager O/W volume ratio (0.025-0.045). It features a tight mesoporous structure with a thin dendritic fibrous in 0.03 to 0.04 O/W volume ratio. The particle sizes, surface areas, and porosity of DFNS were positively correlated with the addition of the silica precursor TEOS. The size of DFNS increased from 123 nm to about 220 nm with the CTAB/TEOS molar ratio decreasing from 0.119 to 0.050. When the molar ratio of CTAB to TEOS =0.119, DFNS has a smaller particle size(123 nm) with a larger surface area and abundant honeycomb mesopores; the low O/W volume ratio strategy provides theoretical support for the industrialization development of DFNS and nano-pesticides, which plays a profound role in promoting the sustainable development of pesticide reduction, efficiency and green agriculture.

A study on the pesticides-loading capacity of dendritic fibrous nano silica synthesized from 1-pentanol-water microemulsion with a low oil-water ratio

“…It is evident that KM has successfully infiltrated the channels of DFNS, while the dendritic fibrous structure of DFNS@KM remains unaltered. According to table 1 and previous research [43], the nitrogen adsorption-desorption isotherm of DFNS exhibits a type IV isotherm. The specific surface area of 749 m 2 g −1 , a pore volume of 1.54 cm 3 g −1 , and a large pore diameter of 8.13 nm.…”

“…The specific surface area of these silica particles ranged from 634.75 to 953.33 m 2 g −1 , while the pore volume ranged from 0.56 to 1.87 cm 3 g −1 . This method provides a less energy-intensive approach for industrial-scale production [43]. Furthermore, DFNS synthesized using this methodology has shown promising potential in formulating sustained-release systems for pesticides.…”