@article {44616, title = {Flexible composite mechanical energy harvester from a ferroelectric organoamino phosphonium salt}, journal = {Angewandte Chemie-International Edition}, volume = {57}, year = {2018}, month = {JUL}, pages = {9054-9058}, abstract = {

A new binary organic salt diphenyl diisopropylamino phosphonium hexaflurophosphate (DPDPPF6) was shown to exhibit a good ferroelectric response and employed for mechanical energy harvesting application. The phosphonium salt crystallizes in the monoclinic noncentrosymmetric space group Cc and exhibits an H-bonded 1D chain structure due to N-HF interactions. Ferroelectric measurements on the single crystals of DPDPPF6 gave a well-saturated rectangular hysteresis loop with a remnant (P-r) polarization value of 6Ccm(-2). Further, composite devices based on polydimethylsiloxane (PDMS) films for various weight percentages (3, 5, 7, 10 and 20wt\%) of DPDPPF6 were prepared and examined for power generation by using an impact test setup. A maximum output peak-to-peak voltage (V-PP) of 8.5V and an output peak-to-peak current (I-PP) of 0.5A was obtained for the non-poled composite film with 10wt\% of DPDPPF6. These results show the efficacy of organic ferroelectric substances as potential micropower generators.

}, keywords = {binary phosphonium salts, energy conversion, ferroelectricity, hydrogen bonding, polymer composites}, issn = {1433-7851}, doi = {10.1002/anie.201805479}, author = {Vijayakanth, Thangavel and Srivastava, Anant Kumar and Ram, Farsa and Kulkarni, Priyangi and Shanmuganathan, Kadhiravan and Praveenkumar, Balu and Boomishankar, Ramamoorthy} } @article {44184, title = {Imido-P(V) trianion supported enantiopure neutral tetrahedral Pd(II) cages}, journal = {Chemical Communications}, volume = {54}, year = {2018}, month = {FEB}, pages = {1873-1876}, type = {Article}, abstract = {

Charge-neutral chiral hosts are attractive due to their ability to recognize a wide range of guest functionalities and support enantio-selective processes. However, reports on such charge-neutral cages are very scarce in the literature. Here, we report an enantiomeric pair of tetrahedral Pd(II) cages built from chiral tris(imido) phosphate trianions and oxalate linkers, which exhibit enantioselective separation capabilities for epichlorohydrin, beta-butyrolactone, and 3-methyl- and 3-ethyl cyclopentanone.

}, issn = {1359-7345}, doi = {10.1039/c8cc00207j}, author = {Rajasekar, Prabhakaran and Pandey, Swechchha and Paithankar, Harshad and Chugh, Jeetender and Steiner, Alexander and Boomishankar, Ramamoorthy} } @article {46205, title = {All-organic composites of ferro- and piezoelectric phosphonium salts for mechanical energy harvesting application}, journal = {Chemistry of Materials}, volume = {31}, year = {2019}, month = {AUG}, pages = { 5964-5972}, type = {A}, abstract = {

Molecular ferroelectrics owing to their lightweight, flexibility, and phase stability are drawing attention in the fields of flexible electronics, optical devices, and energy materials. In this paper, we report a series of binary organoamino phosphonium salts containing triphenyl isopropylaminophosphonium (TPAP), diphenyl diisopropylaminophosphonium (DPDP), phenyl triisopropylaminophosphonium (PTAP), and tetraisopropylaminophosphonium (TIAP) cations supported by lower symmetric tetrahedral BF4-, ClO4-, and IO4- anions. The P-E hysteresis loop measurements on these polar organic salts gave high remnant polarization (P-r) values of 35.36, 21.83, and 21.12 mu C cm(-2) for the DPDP center dot BF4, DPDP center dot ClO4, and DPDP center dot IO4 salts, respectively, having 1D hydrogen-bonded chain structures built from strong N-H center dot center dot center dot X (X = F or 0) interactions. For the first time, highly flexible composite devices have been prepared for the piezoelectric salts TPAP center dot BF4, DPDP center dot BF4, and TIAR center dot BF4 using thermoplastic polyurethane (TPU) as the matrix. The observed maximum peak-to-peak output voltages (V-pp) for the 10 wt \% composite devices of TPAP center dot BF4/TPU, DPDP center dot BF4/TPU, and TIAP center dot BF4/TPU are found to be 7.37, 8.95, and 4.75 V, respectively. These composite devices exhibit excellent durability, cycling stability, and viscoelastic properties. They also show the capacitor charging capabilities reaching their maximum charging points within 60 s.

}, doi = {10.1021/acs.chemmater.9b02409}, author = {Vijayakanth, Thangavel and Ram, Farsa and Praveenkumar, Balu and Shanmuganathan, Kadhiravan and Boomishankar, Ramamoorthy} } @article {46434, title = {Chiral separation of styrene oxides supported by enantiomeric tetrahedral neutral Pd(II) cages}, journal = {Inorganic Chemistry}, volume = {58}, year = {2019}, month = {NOV}, pages = {15017-15020}, type = {Article}, abstract = {

The separation of enantiomers is of considerable importance in the preparation of the compounds of biological interests, catalysis, and drug development. Here, we report a novel enantioseparation of styrene epoxides (SOs) resolved in the presence of a pair of enantio-enriched tetrahedral cages. Chiral neutral cages of formula [(Pd3X*)(4)(C6O4Cl2)(6)] ([X*](3-) = RRR-or SSS-[PO(N(*CH(CH3)Ph)(3)](3)) are constructed from Pcl, building units supported by tris(imido)phosphate trianions and chloranilate linkers. These cages exhibit considerable enantioselective separation capabilities toward a series of styrene epoxides via a crystallization inclusion method. A highest enantiomeric excess (ee) value of up to 80\% is achieved for the (R)-4-fluorostyrene oxide.

}, issn = {0020-1669}, doi = {10.1021/acs.inorgchem.9b02389}, author = {Rajasekar, Prabhakaran and Pandey, Swechchha and Ferrara, Joseph D. and Del Campo, Mark and Le Magueres, Pierre and Boomishankar, Ramamoorthy} } @article {46789, title = {Nanocellulose reinforced flexible composite nanogenerators with enhanced vibrational energy harvesting and sensing properties}, volume = {2}, year = {2020}, month = {JUL}, pages = {2550-2562}, type = {Article}, abstract = {

We report here enhanced vibration and pressure sensing properties of nanocellulose reinforced flexible composite piezoelectric nanogenerators (PENGs). Surface fluorinated nanocellulose crystals (FNC) were incorporated into poly(vinylidene fluoride) (PVDF) and electrospun into composite nanofibers. Incorporation of only 2 wt \% FNC in PVDF resulted in a significant enhancement in pressure sensitivity with a very low detectable pressure limit of 10 Pa and a sensitivity of up to 18 mV/kPa. The composite PENGs also demonstrated very high sensitivity for forced continuous vibrations. 2FNC/PVDF composites resulted in an order of magnitude higher voltage response over neat PVDF for a given strain. When PENGs were mounted on a vacuum pump for transduction of mechanical vibrations into electrical energy, 2FNC/PVDF composite devices manifested similar to 3.8 times enhanced voltage output over neat PVDF and faster charging of a capacitor. The enhanced piezoelectric properties of PVDF/FNC nanocomposites could be attributed to the tailored interface between PVDF and nanocellulose and enhanced polarizability.

}, keywords = {Composite, Nanofiber, piezoelectric, pressure, Sensor, vibration}, issn = {2637-6105}, doi = {10.1021/acsapm.0c00158}, author = {Ram, Farsa and Gudadhe, Aniket and Vijayakanth, Thangavel and Aherrao, Swapnil and Borkar, Vivek and Boomishankar, Ramamoorthy and Shanmuganathan, Kadhiravan} } @article {46893, title = {Piezoelectric energy harvesting from a ferroelectric hybrid salt [Ph3MeP](4)[Ni(NCS)(6)] embedded in a polymer matrix}, journal = {Angewandte Chemie-International Edition}, volume = {59}, year = {2020}, month = {JUN }, pages = {10368-10373}, type = {Article}, abstract = {

Organic-inorganic hybrid ferroelectrics are an exciting class of molecular materials with promising applications in the area of energy and electronics. The synthesis, ferroelectric and piezoelectric energy harvesting behavior of a 3d metal ion-containing A(4)BX(6) type organic-inorganic hybrid salt [Ph3MeP](4)[Ni(NCS)(6)] (1) is now presented. P-E hysteresis loop studies on 1 show a remnant ferroelectric polarization value of 18.71 mu C cm(-2), at room temperature. Composite thermoplastic polyurethane (TPU) devices with 5, 10, 15 and 20 wt \% compositions of 1 were prepared and employed for piezoelectric energy harvesting studies. A maximum output voltage of 19.29 V and a calculated power density value of 2.51 mW cm(-3) were observed for the 15 wt \% 1-TPU device. The capacitor charging experiments on the 15 wt \% 1-TPU composite device shows an excellent energy storage performance with the highest stored energies and measured charges of 198.8 mu J and 600 mu C, respectively.

}, keywords = {energy conversion, mechanical properties, non-covalent interactions, organic-inorganic hybrid composites, Phosphorus}, issn = {1433-7851}, doi = {10.1002/anie.202001250, Early Access Date = APR 2020}, author = {Vijayakanth, Thangavel and Ram, Farsa and Praveenkumar, Balu and Shanmuganathan, Kadhiravan and Boomishankar, Ramamoorthy} } @article {47747, title = { Flexible energy harvester from an organic ferroelectric ammonium salt}, journal = {Chemistry-An Asian Journal}, volume = {16}, year = {2021}, month = {DEC }, pages = {4122-4129}, type = {Article}, abstract = {Organic ferroelectrics due to their low cost, easy preparation, light weight, high flexibility and phase stability are gaining tremendous attention in the field of portable electronics. In this work, we report the synthesis, structure and ferroelectric behavior of a two-component ammonium salt 2, containing a bulky [Bn(4-BrBn)NMe2](+) (Bn=benzyl and 4-BrBn=4-bromobenzyl) cation and tetrahedral (BF4)(-) anion. The structural analysis revealed the presence of rich non-classical C-H...F and C-H...Br interactions in this molecule that were quantified by Hirshfeld surface analysis. The polarization (P) vs. electric field (E) hysteresis loop measurements on 2 gave a remnant polarization (P-r) of 14.4 mu C cm(-2) at room temperature. Flexible polymer composites with various (5, 10, 15 and 20) weight percentages (wt\%) of 2 in thermoplastic polyurethane (TPU) were prepared and tested for mechanical energy harvesting applications. A notable peak-to-peak output voltage of 20 V, maximum current density of 1.1 mu A cm(-2) and power density of 21.1 mu W cm(-2) were recorded for the 15 wt\% 2-TPU composite device. Furthermore, the voltage output generated from this device was utilized to rapidly charge a 100 mu F capacitor, with stored energies and measured charges of 156 mu J and 121.6 mu C, respectively.}, keywords = {Dielectric, energy harvesting, ferroelectricity, organic composites, piezoelectric}, issn = {1861-4728}, doi = {10.1002/asia.202101128}, author = {Gupta, Rishabh and Sahoo, Supriya and Deswal, Swati and Kothavade, Premkumar and Dixit, Prashant and Zareba, Jan K. and Shanmuganathan, Kadhiravan and Boomishankar, Ramamoorthy} } @article {48827, title = {3D-printed polymer composite devices based on a ferroelectric chiral ammonium salt for high-performance piezoelectric energy harvesting}, journal = {Materials Horizons}, volume = {10}, year = {2023}, month = {JUL}, pages = {3153-3161}, type = {Article}, abstract = {

Three-dimensional printing (3DP) is an emerging technology to fabricate complex architectures, necessary to realize state-of-the-art flexible and wearable electronic devices. In this regard, top-performing devices containing organic ferro- and piezoelectric compounds are desired to circumvent significant shortcomings of conventional piezoceramics, e.g. toxicity and high-temperature device processibility. Herein, we report on a 3D-printed composite of a chiral ferroelectric organic salt {[Me3CCH(Me)NH3][BF4]} (1) with a biodegradable polycaprolactone (PCL) polymer that serves as a highly efficient piezoelectric nanogenerator (PENG). The ferroelectric property of 1 originates from its polar tetragonal space group P4(2), verified by P-E loop measurements. The ferroelectric domain characteristics of 1 were further probed by piezoresponse force microscopy (PFM), which gave characteristic {\textquoteleft}butterfly{\textquoteright} and hysteresis loops. The PFM amplitude vs. drive voltage measurements gave a relatively high magnitude of the converse piezoelectric coefficient for 1. PCL polymer composites with various weight percentages (wt\%) of 1 were prepared and subjected to piezoelectric energy harvesting tests, which gave a maximum open-circuit voltage of 36.2 V and a power density of 48.1 mu W cm(-2) for the 10 wt\% 1-PCL champion device. Furthermore, a gyroid-shaped 3D-printed 10 wt\% 1-PCL composite was fabricated to test its practical utility, which gave an excellent output voltage of 41 V and a power density of 56.8 mu W cm(-2). These studies promise the potential of simple organic compounds for building PENG devices using advanced manufacturing technologies.

}, issn = {2051-6347}, doi = {10.1039/d3mh00444a}, author = {Sahoo, Supriya and Kothavade, Premkumar Anil and Naphade, Dipti R. and Torris, Arun and Praveenkumar, Balu and Zareba, Jan K. and Anthopoulos, Thomas D. and Shanmuganathan, Kadhiravan and Boomishankar, Ramamoorthy} }