Resistance of deliquescence and caking to enhance the effective utilization of potassium nitrate: A novel surface modification method by SDS

Abstract

Abstract The deliquescence and caking of potassium nitrate cause a loss of materials functionality as well as unqualified products. Therefore, a method that using various surfactants modified potassium nitrate was carried out. The moisture adsorption and anticaking efficiency performances of modified products were investigated. The modified-KNO3 (M-KNO3) was characterized by contact angle measurement, SEM, XRD, FT-IR and XPS. The results showed that the contact angle of potassium nitrate modified by sodium dodecyl sulfate (SDS) reached 109.6° at the required modification parameters, the moisture adsorption capacity of potassium nitrate decreased by 77% and the anticaking efficiency improved to 90%. The formation of the hydrophobic layer on the surface of potassium nitrate based on the chemical bonding between sodium dodecyl sulfate and K+, which effectively prevented the deliquescence and caking of potassium nitrate. This study revealed a valid reaction mechanism model for a series of deliquescence and caking problems of inorganic salts.