Harnessing molecular rotations in plastic crystals: a holistic view for crystal engineering of adaptive soft materials

Abstract

This review highlights the exceptional properties of plastic crystals, their expanding scope in materials sciences and plenty of opportunities for designing new mechanically soft functional crystals.

Mechanical Bending and Modulation of Photoactuation Properties in a One-Dimensional Pb(II) Coordination Polymer

“…1,[8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] With the upsurge of dynamic crystals, several examples of mechanically flexible crystals have been reported in the literature showing elastic and plastic deformation upon the application of an external force. [27][28][29][30][31][32][33][34] Apart from actuation by mechanical force, photomechanical actuation is of great advantage due to its remotely controlled process. 25,[35][36][37] Examples of flexible crystals and photomechanical actuators have been reported separately in the literature where most of them are organic crystals.…”

“…25,[35][36][37] Examples of flexible crystals and photomechanical actuators have been reported separately in the literature where most of them are organic crystals. 1,2,5,27 However, multi-stimuli responsive crystals are rarely encountered in the literature. 1,8,13,38 In general, fabrication of multifunctional materials demands the combination of several functionalities for imbibing multiple properties.…”

Multistimuli Responsive Dynamic Effects in a One-Dimensional Coordination Polymer

“…Utilization of the supplied energy in the form of light, heat, pressure may result in jumping, explosion, hopping, twisting, and bending of macroscopic crystals. [1][2][3][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Efficient energy transduction by single crystalline materials is attractive because of their dense and ordered packing. Capitalization on the actuating properties may open up avenue for their use in smart energy harvesting materials, soft robotics, artificial muscle etc.…”

Stabilization of Ferroelectric Phase in Highly Oriented Quinuclidinium Perrhenate (HQReO4) Thin Films

“…Plastic molecular crystals exhibiting switchable polarization are a unique class of ferroelectric (FE) materials owing to their environmental friendliness, structural tunability, and mechanical flexibility [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. Compared to inorganic FE materials, the low-temperature processibility of plastic crystals makes it an attractive choice for FE applications [ 9 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. The major drawback of molecular ferroelectric crystals are their low spontaneous polarization, low melting temperature, low Curie temperature, and small dielectric constant, which needs to be improved for replacing it with the inorganic FE materials [ 23 ].…”