Wednesday Colloquia

Crystal engineering of adaptive smart materials: from mechanical bending to self-healing

by Prof. C. Malla Reddy (IISER Kolkata)

Wednesday, September 1, 2021 from to (Asia/Kolkata)
at Online through ZOOM Webinar ( Zoom link: https://zoom.us/j/97963259354?pwd=ZFZsa2xqWGJSZW5pUjZPNkNqeGlEZz09 )
Meeting ID: 979 6325 9354 Pass code: 04072020
Description
High crystallinity, although desired in materials for a wide range of high-performance engineering applications, generally comes with 
undesirable  attributes  such  as  high  brittleness  and  fragility  [1].  This  makes  crystalline  materials  incompatible  with  many  future technologies, such as  flexible devices  and soft-robotics.  Recent progress  in  crystal engineering has brought  into light  many  possible opportunities  to  address  these  issues,  enabling  the  design  of  adaptive  crystalline  materials  that  respond  to  external  stimuli  with exceptional qualities [1-7]. For instance, crystals that bend (elastically or plastically), twist, curl, wind, jump, exfoliate, laminate, and explode,  under  external  stresses,  such  as  mechanical  stress,  pressure,  light,  heat,  solvent,  etc.,  have  been  shown.  On  the  other  hand, until very recent time, self-healing was observed only in soft and amorphous materials, mostly involving approaches that use chemical reactions,  diffusion,  solvent,  vapour,  electricity,  etc.,  with  typical  healing  time  scales  in  minutes  to  weeks  [8].  A  new  self-healing mechanism  that  we  recently  introduced  [9]  in  materials  science,  enables  ultrafast,  near  100%  autonomous  diffusion-less  repair  in crystalline  materials  that  uses  electrostatic  surface  potentials  generated  on  the  freshly  created  fracture  surfaces,  inherent  to  certain 
types of polar single crystals. My talk will cover structure-property correlation for crystal engineering of adaptive materials

References: 

[1] Saha, S., Mishra, M. K., Reddy, C. M. & Desiraju, G. R. (2018) Acc. Chem. Res. 51, 2957.
[2] Reddy, C. M., Gundakaram, R. C., Basavoju, S., Kirchner, M. T., Padmanabhan, K. A. & Desiraju, G. R. (2005), Chem. Commun. 3945.
[3] Ghosh, S. & Reddy, C. M. (2012) Angew. Chem. Int. Ed., 51, 10319.
[4] Krishna. G. R., Devarapalli, R., Lal, G. & Reddy, C. M. (2016) J. Am. Chem. Soc., 138, 13561.
[5] Naumov, P., Chizhik, S., Panda, M. K., Nath, N. K. & Boldyreva, E. (2015) Chem. Rev., 115, 12440.
[6] Mondal, A., Bhattacharya, B., Das, S., Bhunia, S., Chowdhury, R., Dey, S. & Reddy, C. M. (2020) Angew. Chem. Int. Ed. 59 ,10971.
[7] Takamizawa, S. & Miyamoto, Y. (2014) Angew. Chem. Int. Ed. 53, 6970.
[8] Yanagisawa, Y., Nan, Y., Okuro, K. & Aida, T. (2018) Science, 359, 72.
[9] Bhunia, S., Chandel, S., Karan, S. K., Dey, S., Tiwary, A., Das, S., Kumar, N., Chowdhury, R., Mondal, S., Ghosh, S., Mondal, A.,Khatua, B. B., Ghosh, N & Reddy, C. M. (2021), Science, 373, Issue 6552, pp. 321-327.