Ganguly, Sayan; Maity, Priti Prasanna; Mondal, Subhadip; Das, Poushali; Bhawal, Poushali; Dhara, Santanu; Das, Narayan Ch.
Polysaccharide and poly(methacrylic acid) based biodegradable elastomeric biocompatible semi-IPN hydrogel for controlled drug delivery
Nanoparticles embedded semi-interpenetrating (semi-IPNs) polymeric hydrogels with enhanced mechanical toughness and biocompatibility could have splendid biomedical acceptance. Here we propose poly(methacrylic acid) grafted polysaccharide based semi-IPNs filled with nanoclay via in situ Michael type reaction associated with covalent crosslinking with N,N-methylenebisacrylamide (MBA). The effect of…
Precise inter-lamellar/inter-fibrillar localization and consequent fabrication of porous membranes with crystallization-modulated pore-size
Ye, Cuicui; Zhao, Jinxing; Ye, Lijun; Jiang, Zhiyong; You, Jichun; Li, Yongjin
In poly(vinylidene fluoride)/poly(1,4-butylene succinate) (i.e. PVDF/PBSU) blend, the precise inter-lamellar or inter-fibrillar localization of PVDF crystal lamellae has been achieved. In the specimen with PVDF 70 wt%, comparable PVDF and PBSU volume fractions result in the inter-lamellar structures. When PVDF acts as the minority phase (PVDF 30 wt%), its crystal lamellae locate…
Precursor non-stoichiometry to enable improved CH3NH3PbBr3 nanocrystal LED performance
Chandran, Bevita K.; Veldhuis, Sjoerd A.; Chin, Xin Yu; Bruno, Annalisa; Yantara, Natalia; Chen, Xiaodong; Mhaisalkar, Subodh
High photoluminescence quantum yields and narrow emission wavelengths, combined with low temperature solution processing, make CH3NH3PbBr3 nanocrystals (NCs) favorable candidates for light-emitting applications. Herein, we describe the synthesis of CH3NH3PbBr3 NC inks by a convenient room-temperature ligand assisted reprecipitation protocol. We further investigate the effect of modulation of the…
Processing of PVDF-based electroactive/ferroelectric films: importance of PMMA and cooling rate from the melt state on the crystallization of PVDF beta-crystals
Neef, Alexandre De; Samuel, Cédric; Stoclet, Grégory; Rguiti, Mohamed; Courtois, Christian; Dubois, Philippe; Soulestin, Jérémie; Raquez, Jean-Marie
Poly(vinylidene difluoride) (PVDF) displays attractive ferroelectric/piezoelectric properties and its polar β-crystals are specifically targeted for achieving electroactive applications. However, their direct crystallization from the melt state represents a challenging task that has never been addressed using melt-state processes. The use of poly(methyl methacrylate) (PMMA) is herein investigated…
Radiopaque Highly Stiff and Tough Shape Memory Hydrogel Microcoils for Permanent Embolization of Arteries
Zhang, Yinyu; Gao, Haijun; Wang, Hao; Xu, Ziyang; Chen, Xiaowei; Liu, Bo; Shi, Yuan; Lu, Ying; Wen, Lianfang; Li, Yan; Li, Zhisheng; Men, Yongfeng; Feng, Xuequan; Liu, Wenguang
Transcatheter arterial embolization of aneurysm with metal microcoils is notoriously prone to recanalization arising from the low filling ratio due to their extreme rigidity. Smart hydrogel microcoils with tunable modulus may essentially significantly improve the therapeutic efficacy. Here, a radiopaque highly stiff body-temperature-triggered shape memory (SM) hydrogel is fabricated for…
Relation between thermal effects and structural changes under deformation of thermoplastics
Guseva, M. A.; Gerasin, V. A.; Shklyaruk, B. F.; Dubinskiy, V. A.
The article reports thermal effects accompanying deformation of widely used thermoplastics: PE of different density, highly isotactic and stereodefective PP, PA6, PC. A number of structural methods (X-ray diffraction at large and small angles, DSC, IR spectroscopy, microscopy, volume measurements) were used to establish the factors underlying generation of heat…
Rapid, Acid-Free Synthesis of High-Quality Graphene Quantum Dots for Aggregation Induced Sensing of Metal Ions and Bioimaging
Nair, Raji V.; Thomas, Reny Thankam; Sankar, Vandana; Muhammad, Hanif; Dong, Mingdong; Pillai, Saju
Graphene quantum dots (GQDs) are zero-dimensional materials that exhibit characteristics of both graphene and quantum dots. Herein, we report a rapid, relatively green, one-pot synthesis of size-tunable GQDs from graphene oxide (GO) by a sonochemical method with intermittent microwave heating, keeping the reaction temperature constant at 90 °C. The GQDs…
Retardance of Form II to Form I Transition in Polybutene-1 at Late Stage: A Proposal of a New Mechanism
Qiao, Yongna; Wang, Hai; Men, Yongfeng
The retardation of polybutene-1 form II to form I transition in the late stage has been investigated by means of time-resolved wide-angle X-ray diffraction. Form II samples with different lamellar thickness and constituent in amorphous phase were generated via varying crystallization temperature and molecular weight and aged at room temperature…
Self-Assembled 3D Helical Hollow Superstructures with Enhanced Microwave Absorption Properties
Yang, Yang; Zhang, Jianqi; Zou, Wenjun; Wu, Sai; Wu, Fan; Xie, Aming; Wei, Zhixiang
Helical structures at different scales endow functional materials with special optical, electrical, and magnetic properties. However, methods for constructing and regulating single-handed helicity, particularly complex 3D hierarchical structures, remain limited. In this study, co-self-assembly process combined with emulsion droplets is used to produce the various well-defined 3D hollow…
Sensitivity of Polymer Crystallization to Shear at Low and High Supercooling of the Melt
Rhoades, Alicyn M.; Gohn, Anne M.; Seo, Jiho; Androsch, René; Colby, Ralph H.
Flow-induced crystallization (FIC) is a dominant mechanism of polymer self-assembly, but the process is poorly understood at high supercooling and under fast cooling conditions because of structural rearrangements that occur during slow heating and cooling conditions typically used for investigation. Incorporating fast-scanning chip calorimetry techniques, the influence that specific amounts…