01943nas a2200241   4500008004100000022001400041245007900055210006900134260000800203300001400211490000700225520118000232100001801412700001701430700002401447700002201471700002101493700002201514700002001536700001801556700001901574856010801593       2019                        eng d  a1528-748300aCrystalline acylhydrazone photoswitches with multiple mechanical responses0 aCrystalline acylhydrazone photoswitches with multiple mechanical  cMAY  a3039-30440 v193 a<p>The advancement of our understanding of stimuli responsive molecular crystals has led to the realization that they hold great yet unexplored potential as adaptive materials. Although molecular crystals that exhibit a single mechanical response to a single input stimulus are now abundant, crystals that are capable of response to multiple stimuli are rather scarce. Here we report two photoswitchable acylhydrazone derivatives, Ac-1 and Ac-2, which respond to light as well as to mechanical force. Upon application of localized mechanical stress, the anhydrous (Ac-1a) and monohydrate (Ac-1h) crystals of Ac-1 undergo plastic shearing deformation and bending, whereas monohydrate crystals of Ac-2 undergo elastic deformation. When they are exposed to UV light, crystals of Ac-1h and Ac-2 undergo photoinduced bending; on the other hand, crystals of Ac-1a and thicker crystals of Ac-2 exhibit photosalient effect (light-induced leaping). It is demonstrated that the synergistic action of multiple stimuli (UV light and force) elicits enhanced mechanical response, and this strategy could be employed in the future to increase the efficacy of single crystal actuators.</p>
1 aGupta, Poonam1 aPanda, Tamas1 aAllu, Suryanarayana1 aBorah, Silpisikha1 aBaishya, Anamika1 aGunnam, Anilkumar1 aNangia, Ashwini1 aNaumov, Pance1 aNath, Naba, K.  uhttp://library.ncl.res.in/content/crystalline-acylhydrazone-photoswitches-multiple-mechanical-responses02388nas a2200265   4500008004100000022001400041245006000055210005900115260000800174300001200182490000700194520158300201653001901784653002801803653003301831653002301864653001101887100002701898700002401925700001801949700002401967700001901991700002402010856008802034       2023                        eng d  a1060-132500aEmerging trends in olefin polymerization: a perspective0 aEmerging trends in olefin polymerization a perspective  cNOV  a731-7500 v603 a<p>The seemingly matured field of olefin polymerization still poses several challenges and holds enormous potential to meet contemporary material requirements. In this feature article, we examine the progress of olefin polymerization in the last two decades. Among the several emerging trends, we identify four most impactful discoveries, namely, (i) disentangled ultra-high molecular weight polyethylene (dUHMWPE), (ii) disubstituted functional olefin copolymerization, (iii) incorporation of bioderived comonomers in polyolefins, and (iv) application of above (ii, iii) functional polyolefins as compatibilizers. The dUHMWPE has attracted significant attention and heterogeneous Ziegler-type catalysts, homogenous metallocene, and post-metallocene catalysts have been reported to produce disentangled ultrahigh molecular weight polyethylene. Insertion copolymerization of difunctional disubstituted olefins has been reported only recently and ortho-phosphinobenzene sulfonate palladium catalyst outperforms the other catalysts. Interestingly, insertion copolymerization of bioderived olefins has witnessed a surge in the number of reports. Sugar and plant oil-derived olefins have been copolymerized with ethylene to obtain relatively hydrophilic polyethylene. The functional polyethylene is finding a new application as compatibilizer or displays better adhesion to surfaces. Thus, the feature article offers a succinct account of emerging trends in polyolefins, identifies the most impactful contributions, and debates the application potential of these new materials.</p>
10acompatibilizer10aFunctional polyethylene10aInsertion (co)polymerization10arenewable monomers10auHMWPE1 aBirajdar, Rajkumar, S.1 aBodkhe, Dnyaneshwar1 aGupta, Poonam1 aShaikh, Maulali, H.1 aRamekar, Rohan1 aChikkali, Samir, H.  uhttp://library.ncl.res.in/content/emerging-trends-olefin-polymerization-perspective