02695nas a2200181   4500008004100000022001400041245009400055210006900149260000900218300001400227490000700241520205600248100002102304700002902325700002202354700001702376856012002393       2021                        eng d  a0743-746300aMechanism of adhesion of natural polymer coatings to chemically modified siloxane polymer0 aMechanism of adhesion of natural polymer coatings to chemically   cMAR   a2974-29840 v373 a<p>Surface coatings play an important role in improving the performance of biomedical implants. Polydimethylsiloxane (PDMS) is a commonly used material for biomedical implants, and surface-coated PDMS implants frequently face problems such as delamination or cracking of the coating. In this work, we have measured the performance of nano-coatings of the biocompatible protein polymer silk fibroin (SF) on pristine as well as modified PDMS surfaces. The PDMS surfaces have been modified using oxygen plasma treatment and 3-amino-propyltriethoxy-silane (APTES) treatment. Although these techniques of PDMS modification have been known, their effects on adhesion of SF nano-coatings have not been studied. Interestingly, testing of the coated samples using a bulk technique such as tensile and bending deformation showed that the SF nano-coating exhibits improved crack resistance when the PDMS surface has been modified using APTES treatment as compared to an oxygen plasma treatment. These results were validated at the microscopic and mesoscopic length scales through nano-scratch and nano-indentation measurements. Further, we developed a unique method using modified atomic force microscopy to measure the adhesive energy between treated PDMS surfaces and SF molecules. These measurements indicated that the adhesive strength of PDMS-APTES-SF is 10 times more compared to PDMS-O-2-SF due to the higher number of molecular linkages formed in this nanoscale contact. This lower number of molecular linkages in the PDMS-O-2 indicates that only fewer numbers of surface hydroxyl groups interact with the SF protein through secondary interactions such as hydrogen bonding. On the other hand, a larger number of amine groups present on PDMS-APTES surface hydrogen bond with the polar amino acids present on the silk fibroin protein chain, resulting in better adhesion. Thus, APTES modification to the PDMS substrate results in improved adhesion of nano-coating to the substrate and enhances the delamination and crack resistance of the nano-coatings.</p>1 aJoseph, Emmanuel1 aRajput, Shatruhan, Singh1 aPatil, Shivprasad1 aNisal, Anuya  uhttps://library.ncl.res.in/content/mechanism-adhesion-natural-polymer-coatings-chemically-modified-siloxane-polymer02456nas a2200301   4500008004100000022001400041245016000055210006900215260000900284300001600293490000700309520139100316653003101707653003201738653002601770653002801796653002401824653002101848100001701869700002301886700002001909700002901929700001901958700000501977700002201982700002502004856012502029       2021                        eng d  a1944-824400aResistive switching in HfO2-x/La0.67Sr0.33MnO3 heterostructures: an intriguing case of low H-field susceptibility of an E-field controlled active interface0 aResistive switching in HfO2xLa067Sr033MnO3 heterostructures an i  cNOV   a54133-541420 v133 aHigh-performance nonvolatile resistive random access memories (ReRAMs) and their small stimuli control are of immense interest for high-speed computation and big-data processing in the emerging Internet of Things (IoT) arena. Here, we examine the resistive switching (RS) behavior in growth-controlled HfO2/La0.67Sr0.33MnO3 (LSMO) heterostructures and their tunability in a low magnetic field. It is demonstrated that oxygen-deficient HfO2 films show bipolar switching with a high on/off ratio, stable retention, as well as good endurance owing to the orthorhombic-rich phase constitution and charge (de)trapping-enabled Schottky-type conduction. Most importantly, we have demonstrated that RS can be tuned by a very low externally applied magnetic field (similar to 0-30 mT). Remarkably, application of a magnetic field of 30 mT causes RS to be fully quenched and frozen in the high resistive state (HRS) even after the removal of the magnetic field. However, the quenched state could be resurrected by applying a higher bias voltage than the one for initial switching. This is argued to be a consequence of the electronically and ionically ``active'' nature of the HfO2-x/LSMO interface on both sides and its susceptibility to the electric and low magnetic field effects. This result could pave the way for new designs of interface-engineered high-performance oxitronic ReRAM devices.10acharge trapping-detrapping10alow external magnetic field10aoxide-oxide interface10apulsed laser deposition10aresistive switching10aSchottky barrier1 aAntad, Vivek1 aShaikh, Parvez, A.1 aBiswas, Abhijit1 aRajput, Shatruhan, Singh1 aDeo, Shrinivas1 a1 aPatil, Shivprasad1 aOgale, Satishchandra  uhttps://library.ncl.res.in/content/resistive-switching-hfo2-xla067sr033mno3-heterostructures-intriguing-case-low-h-field