@article {49094, title = {Enhancing the crystallization kinetics and mechanical properties of poly(lactic acid) blends for 3D printing application}, journal = {ACS Applied Polymer Materials }, volume = {6}, year = {2024}, month = {MAY }, pages = {5754-5762}, type = {Article}, abstract = {

3D printing of poly(lactic acid) (PLA) blends has been attempted to resolve issues such as inherent brittleness and slow crystallization rate of PLA. However, a persistent challenge remains in the form of phase separation or gradual migration of the blended soft polymer or plasticizers. To simultaneously enhance the miscibility of the blends and toughness of 3D-printed parts, a triblock copolymer PLA-PEG-PLA was synthesized and blended with PLA in varying proportions (5, 10, 15, and 20 wt \%). Blending only 10-20 wt \% low molecular weight PLA-PEG-PLA into PLA yielded a miscible blend that showed a 45-fold increase in elongation at break and a 23-fold enhancement in toughness over neat PLA. Scanning electron microscopy (SEM) images of fractured cross sections revealed a brittle to ductile transition in 3D-printed PLA/PLA-PEG-PLA samples. Isothermal crystallization studies and data analysis using the Avrami equation showed an enhancement in the crystal growth rate and overall rate of crystallization. The blends achieved half of their crystallinity in approximately 3 min, a significant improvement over the 9 min required by PLA alone. This underscores the efficiency of our approach. This was also evident in the spherulite growth of 3D-printed PLA and mPLA blends when examined using polarized optical microscopy (POM). To the best of our knowledge, this is the first report exploring the use of blends that include PLA and low molecular weight PLA-PEG-PLA triblock copolymers for 3D printing applications.

}, keywords = {Crystallization, FFF 3D printing, PLA-PEG-PLA triblock copolymer, poly(lacticacid), toughness}, issn = {2637-6105}, doi = {10.1021/acsapm.4c00428}, author = {Kothavade, Premkumar and Yadav, Prashant and Gopal, Animesh and Pol, Harshawardhan and Kafi, Abdullah and Bateman, Stuart and Shanmuganathan, Kadhiravan} } @article {49266, title = {Entropy-driven reversible melting and recrystallization of layered hybrid perovskites}, journal = {SMALL}, volume = {20}, year = {2024}, month = {NOV}, type = {Journal Article}, keywords = {hybrid perovskites, photodetector, reversible melting}, issn = {1613-6810}, doi = {10.1002/smll.202406735}, author = {Rajput, Parikshit Kumar and Salunkhe, Parashurama and Sarma, Manmayuri and Basu, Meghasree and Gopal, Animesh and Joshi, Aprajita and Shingote, Ajinkya Sundarnath and Saha, Surajit and Rahman, Atikur and Nag, Angshuman} } @article {49901, title = {Highly moisture-stable ferroelectric ammonium phosphate salt showing piezoelectric energy harvesting and rotation sensing applications}, journal = {Journal of Materials Chemistry A}, volume = {13}, year = {2025}, month = {JUL}, pages = {22574-22582}, type = {Article}, abstract = {

Ferroelectric phosphate-based materials are known for their biocompatibility, dipole switching, and high thermal stability. In this context, we report a novel organic ferroelectric material, diisopropylammonium bis(4-nitrophenyl) phosphate (DIPABNPP), crystallizing in the monoclinic C2 space group. DIPABNPP exhibits a high second harmonic generation (SHG) efficiency 2.5 times higher than that of potassium dihydrogen phosphate (KDP). The ferroelectric nature of DIPABNPP was confirmed by the observation of a rectangular P-E hysteresis loop, which gave a saturated polarization value of 6.82 mu C cm-2. The ferroelectric polar domains of DIPABNPP, along with the bias-dependent amplitude butterfly and phase hysteresis loops, were visualized by piezoresponse force microscopy (PFM). Furthermore, the polydimethyl siloxane (PDMS) composites of DIPABNPP enabled the fabrication of humidity-resistant piezoelectric nanogenerators (PENGs) with energy harvesting and mechanical-electrical sensing capabilities. The top-performing 10 wt\% DIPABNPP-PDMS device achieved a peak output voltage of 9.5 V and a charge storage efficiency of 81.8\%, successfully powering 53 LEDs. Additionally, its rapid response time of 18.5 ms enables precise rotation sensing capabilities, suggesting potential applications in motion monitoring, such as revolution per minute (RPM) counting. We also present a unique and refined method for obtaining the output work efficiency (OWE) parameter, which quantifies the ratio of harvested electrical energy to the maximum elastic energy stored in the composite device, taking into consideration several key parameters during the PENG measurements. For the 10 wt\% DIPABNPP-PDMS composite, an OWE of 13.1\% was achieved, highlighting both its current performance and potential for optimization. This metric provides a standardized approach for evaluating PENGs, addressing a critical gap in assessing mechanical-to-electrical energy conversion efficiency.

}, issn = {2050-7488}, doi = {10.1039/d5ta01846c}, author = {Kushwaha, Vikash and Prajesh, Neetu and Gopal, Animesh and Sahoo, Supriya and Deswal, Swati and Kirana, Antonysylvester and Shanmuganathan, Kadhiravan and Zareba, Jan K. and Boomishankar, Ramamoorthy} } @article {49451, title = {Ultrabroad near infrared emitting perovskites}, journal = {Angewandte Chemie-International Edition}, volume = {64}, year = {2025}, month = {JAN}, type = {Article}, abstract = {

Phosphor converted light emitting diodes (pc-LEDs) have revolutionized solid-state white lighting by replacing energy-inefficient filament-based incandescent lamps. However, such a pc-LED emitting ultrabroad near-infrared (NIR) radiations still remains a challenge, primarily because of the lack of ultrabroad NIR emitting phosphors. To address this issue, we have prepared 2.5 \% W4+-doped and 2.8 \% Mo4+-doped Cs2Na0.95Ag0.05BiCl6\ perovskites emitting ultrabroad NIR radiation with unprecedented spectral widths of 434 and 468 nm, respectively. Upon band-edge excitation, the soft lattice of the host exhibits broad self-trapped exciton (STE) emission covering NIR-I (700 nm), which then nonradiatively excites the dopants. The\ mathematical equation\ {\textendash}donor ligand Cl-\ reduces the energy of dopant\ d{\textendash}d\ transitions emitting NIR-II with a peak at ~950 nm. Vibronic coupling broadens the dopant emission. The large spin-orbit coupling and local structural distortion might possibly enhance the dopant emission intensity, leading to an overall NIR photoluminescence quantum yield ~40 \%. The composite of our ultrabroad NIR phosphors with biodegradable polymer polylactic acid could be processed into free-standing films and 3D printed structures. Large (170mathematical equation\ 170 mathematical equation\ ), robust, and thermally stable 3D printed pc-LED panels emit ultrabroad NIR radiation, demonstrating NIR imaging applications.

}, doi = {https://doi.org/10.1002/anie.202415003}, author = {Saikia, Sajid and Gopal, Animesh and Rathod, Radha and Joshi, Aprajita and Priolkar, K. R. and Saha, Surajit and Santra, Pralay K. and Shanmuganathan, Kadhiravan and Nag, Angshuman} } @article {49685, title = {Upcycling of postconsumer recyclate polypropylene into low warping and high toughness 3D printable filaments}, journal = {ACS Applied Polymer Materials}, volume = {7}, year = {2025}, month = {JUN }, pages = {7373-7381}, type = {Article}, abstract = {

Polypropylene (PP) is widely used in commodity applications owing to its chemical stability, mechanical properties and low cost. However, almost 50\% of the produced PP ends up as postconsumer waste (PCW) within a short period of usage. Being a non-biodegradable polymer, recycling PCW PP is important to mitigate plastic waste in landfills. Nonetheless, recycling or upcycling postconsumer recyclate (PCR) PP into valuable resources without deterioration in physical and mechanical properties is a challenge. This report presents an approach to upcycle PCR polypropylene (rPP) into high quality 3D printing filament that not only prints with very low warpage but with significantly high elongation at break and toughness. Incorporation of poly(butylene adipate-co-terephthalate) (PBAT) along with maleic anhydride grafted polypropylene (MAPP) in specific proportions led to a significant enhancement in mechanical properties, miscibility, crystallization behavior, and 3D printability. rPP/PBAT blends with 20 wt \% PBAT and 10 wt \% MAPP exhibited a 62-fold enhancement in elongation at break over rPP (from 1.88 to 118.29\%) and a 72-fold increase in toughness (from 2 to 143.60 kJ/m3) with almost similar tensile strength. The final printed components had better layer adhesion and structural stability with a dramatic decrease in warpage, from 25.82\% for pristine rPP to only 7.86\% for rPP/PBAT blend. Isothermal crystallization studies and data analysis using the Avrami equation showed that crystallization half-time (t 1/2), which measures the duration needed for half of the total crystallinity to form, increased from 12.6 s for rPP to 66 s for the rPP/PBAT blend. This report demonstrates an approach to upcycle PCR PP, a positive step toward realizing the goals of circular economy and sustainable additive manufacturing.

}, keywords = {Crystallization, FFF 3D printing, polypropylene/poly(butylene adipate-co-terephthalate)blends, toughness, warpage}, issn = {2637-6105}, doi = {10.1021/acsapm.5c00942}, author = {Gopal, Animesh and Patil, Prashant and Pol, Harshawardhan and Shanmuganathan, Kadhiravan} }