Elucidation of the compressive deformation behaviour of α-lactose monohydrate and anhydrous α-lactose single crystals by mechanical strength and acoustic emission analyses

Abstract

Compressive deformation studies on single α-lactose crystals by mechanical strength and acoustic emission analyses revealed a distinct difference in the deformation behaviour of α-lactose monohydrate and anhydrous α-lactose. α-Lactose monohydrate monocrystals were found to exhibit greater mechanical strength when compared with the anhydrous α-lactose crystals. The acoustic emission data show that the fragmentation process of the monohydrate crystals is acoustically more active and energetic. Amplitude distribution analysis of the acoustic signals further confirmed that the nature of fragmentation during the deformation of the two types of lactose was different. This is attributed to fundamental differences in the internal crystal structure of the two lactose types. This work shows that mechanical strength and acoustic emission analyses provide an insight into the fundamental deformation characteristics of these two types of lactose.