Sabnis Sarvesh S, Gogate Parag R
Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019, India.
Ultrason Sonochem. 2019 Jun;54:198-209. doi: 10.1016/j.ultsonch.2019.01.037. Epub 2019 Jan 28.
The present study investigates the use of ultrasound in size reduction based on recrystallization of a commercially important compound, 3,3'-diaminodiphenyl sulfone, popularly known as DADPS. Typically the applications of DADPS depends on the size distribution, more importantly on the mean size and hence the ultrasound assisted recrystallization has been applied for controlling the size as an alternative to energy intensive mechanical size reduction. For the size reduction studies, DADPS was dissolved in methanol and irradiated with ultrasound during the anti-solvent crystallization operation using water. Effect of different operating parameters such as temperature, rate of addition of antisolvent and its nature (whether neutral, acidic or basic) and ultrasonic parameters such as time of irradiation, power dissipation and duty cycle on the mean size and overall distribution has been studied. The particle characteristics of the original sample and processed samples have been analyzed using particle size analyzer, optical microscopy and X-Ray Diffraction (XRD). The positive effect of ultrasound for size reduction was clearly established from particle size analysis with reduction in the mean size to almost one-third the initial value under optimum conditions of 100 W as the power dissipation, 70% as the duty cycle and 60 min as the time of operation. In terms of the trends of the operating parameters, an increase in the rate of addition of antisolvent yielded the best results in terms of lower size and also alkaline conditions for antisolvent gave better size reduction. The microscopic images revealed a uniform and well-defined crystal shape on processing using ultrasound while XRD analysis established that ultrasound did not alter the crystalline structure. Ultrasound was overall established as an effective approach for size reduction without any changes in the crystalline structure.
本研究探讨了超声在基于一种商业上重要的化合物——3,3'-二氨基二苯砜（俗称DADPS）重结晶的粒度减小方面的应用。通常，DADPS的应用取决于粒度分布，更重要的是取决于平均粒度，因此超声辅助重结晶已被应用于控制粒度，作为能量密集型机械粒度减小的替代方法。对于粒度减小研究，将DADPS溶解在甲醇中，并在使用水的反溶剂结晶操作过程中用超声辐照。研究了不同操作参数（如温度、反溶剂的添加速率及其性质（中性、酸性或碱性））以及超声参数（如辐照时间、功率耗散和占空比）对平均粒度和总体分布的影响。使用粒度分析仪、光学显微镜和X射线衍射（XRD）分析了原始样品和处理后样品的颗粒特性。通过粒度分析清楚地确定了超声对粒度减小的积极作用，在100 W功率耗散、70%占空比和60分钟操作时间的最佳条件下，平均粒度减小到初始值的近三分之一。就操作参数的趋势而言，反溶剂添加速率的增加在较低粒度方面产生了最佳结果，并且反溶剂的碱性条件给出了更好的粒度减小效果。微观图像显示在使用超声处理时晶体形状均匀且明确，而XRD分析确定超声没有改变晶体结构。总体而言，超声被确立为一种有效的粒度减小方法，且晶体结构没有任何变化。
