02152nas a2200253   4500008004100000022001400041245015200055210006900207260000800276300001400284490000700298520126500305653001201570653001601582653002701598653002201625653002101647100001501668700001801683700001701701700002701718700003101745856012201776       2021                        eng d  a0969-023900aElastic piezoelectric aerogels from isotropic and directionally ice-templated cellulose nanocrystals: comparison of structure and energy harvesting0 aElastic piezoelectric aerogels from isotropic and directionally   cJUL  a6323-63370 v283 a<p>We report the preparation of highly compressible and elastic piezoelectric aerogels of carboxylated cellulose nanocrystals (CNCs). Aqueous CNC dispersions containing polyethyleneimine and crosslinker were frozen isotropically to yield isotropic aerogels, while oriented aerogels were prepared by directional freezing. These aerogels were highly flexible and porous (similar to 85% void fraction), exhibiting greater than 90% recovery at 50% compressive strain even after 100 compression-decompression cycles. Since such aerogels with low bulk modulus and high anisotropy would be an ideal platform for leveraging the piezoelectric properties of CNCs, we used them to prepare piezoelectric nanogenerator devices and determined their energy transduction behavior. Anisotropic aerogels led to an enhanced open-circuit voltage of 840 mV (at similar to 8 N applied force), which is over 2.6 times higher than isotropic aerogels (320 mV). The energy density of anisotropic aerogels was around 52 nW/cm(2), representing outstanding piezoelectric performance for cellulose-based aerogels. Such aerogels with high compressibility, elastic recovery and exceptional piezoelectric performance could have potential applications in sensors, wearable electronics, etc.</p>10aAerogel10aAnisotropic10aCellulose nanocrystals10aenergy harvesting10aPiezoelectricity1 aRam, Farsa1 aBiswas, Bipul1 aTorris, Arun1 aKumaraswamy, Guruswamy1 aShanmuganathan, Kadhiravan  uhttps://library.ncl.res.in/content/elastic-piezoelectric-aerogels-isotropic-and-directionally-ice-templated-cellulose