Scale-up disaggregation of palygorskite crystal bundles via ultrasonic process for using as potential drilling fluid

High-efficient disaggregation of palygorskite (PAL) crystal aggregates into individual nanorods is the key to exploiting its nanometer properties, which remains a challenge at present. The sonochemical cavitation effects have been successfully employed for the intensification of physical and chemical processing applications, but it still lacks the relevant study on the scale-up disaggregation of PAL crystal bundles. Here, the energy-efficient, scale-up ultrasonic process was developed to disaggregate PAL aggregates in batches, and the effects of ultra-sonic treatment time, temperature, and power on physicochemical features of PAL were systematically investi-gated. The results showed that the single dispersed PAL nanorods could be continuously produced by sonicating 15 wt% of PAL suspension at 20 kHz, 2000 W and 30 C for 5 min retaining the original nanorod length and layered-chain structure. It also greatly improved the dispersion of nanorod crystal, specific surface area and suspension stability of PAL. The ultrasonically disaggregated PAL has a higher pulping rate in water (14.96 m3/t) and saturated NaCl system (14.45 m3/t), which is significantly better than that of natural PAL in water (14.72 m3/t) and saturated NaCl solution (12.37 m3/t). It suggests that the disaggregated PAL exhibits excellent po-tential and adaptability as a viscosity enhancer for drilling fluid. Therefore, this work provides a feasible and efficient ultrasonic process for large-scale industrialized disaggregation of PAL crystal bundles, laying a foun-dation for the high-value utilization of natural PAL as one-dimensional nanomaterials.

Automated summary

This study developed an energy-efficient, scale-up ultrasonic process to disaggregate palygorskite aggregates into individual nanorods. The effects of ultrasonic treatment time, temperature, and power on the physicochemical features of palygorskite were investigated. The results showed that ultrasound treatment at specific conditions could continuously produce dispersed palygorskite nanorods while retaining their original characteristics. The disaggregated palygorskite exhibited improved dispersion, specific surface area, and suspension stability, making it a potential viscosity enhancer for drilling fluid.