Synthesis of Multiwalled Carbon Nanotube-Reinforced Polyborosiloxane Nanocomposites with Mechanically Adaptive and Self-Healing Capabilities for Flexible Conductors

Abstract

Intrinsic self-healing polyborosiloxane (PBS) and its multi-walled carbon nanotube (MWCNT)-reinforced nanocomposites were synthesized from hydroxyl terminated poly(dimethylsiloxane) (PDMS) and boric acid at room temperature. The formation of Si-O-B moiety in PBS was confirmed by Fourier transform infrared spectroscopy. PBS and its MWCNT-reinforced nanocomposites were found possessing water or methanol activated mechanically adaptive behaviors; the compressive modulus decreased substantially when exposed to water or methanol vapor and recovered their high value after the stimulus was removed. The compressive modulus was reduced by 76%, 86%, 90% and 83% for neat PBS and its nanocomposites containing 3.0 wt.%, 6.2 wt.% and 13.3 wt.% MWCNTs, respectively, in water vapor, and the modulus reduction activated by methanol vapor was greater than by water vapor. MWCNTs at higher contents acted as a continuous electrical channel in PBS offering electrical conductivity, which was up to 1.21 S/cm for the nanocomposite containing 13.3 wt.% MWCNTs. The MWCNT-reinforced PBS nanocomposites also showed excellent mechanically and electrically self-healing properties, moldability and adhesion to PDMS elastomer substrate. These properties enabled a straightforward fabrication of self-repairing MWCNT/PBS electronic circuits on PDMS elastomer substrates.

Chemoselective and Catalyst‐Free O‐Borylation of Silanols: A Facile Access to Borasiloxanes

“…The applications of silicon and boron derivatives in organic and inorganic chemistry are innumerable and their compounds containing bonds with other heteroatoms have received considerable attention, particularly as reagents in metal‐free reactions . The B‐O‐Si moiety is common in material chemistry, especially in the synthesis of poly(borosiloxane)s, which show unique and valuable properties, including high stability and heat resistance . Efficient and chemoselective procedures for the synthesis of borasiloxanes are thus both very important and highly desirable.…”

“…The reaction progress was monitored by GC and GC-MS analyses. After the reaction was completed, the excess toluene and hydroborane (which was as ingle residue) were removed under reduced pressure to give the corresponding products (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13).…”

Multifunctional Skin‐Inspired Flexible Sensor Systems for Wearable Electronics

“…To achieve more reliable self‐healing systems with higher conductivities as well as better mechanical stability, a promising strategy is to merge conducting fillers into nonconductive self‐healing matrices, allowing the formation of conductive self‐healing composites. Until now, a number of materials have been employed to serve as conducting fillers, such as metallic nanowires, graphene based materials, CNTs, metal particles, liquid metal, or ionic liquid for the sake of improving performance of the self‐healing material‐based devices. A pioneering work is made by Tee et al via incorporating micronickel (µNi) particles into a supramolecular polymeric hydrogen‐bonding network .…”

Introduction of Boron Functionalities into Silsesquioxanes: Novel Independent Methodologies

“…[23][24][25][26][27][28] On the other hand, the boron modification of variousc ompounds, [29][30][31][32][33] polymers, [34,35] and nanoparticles is attractivef or aw ide range of applications. [39][40][41] As such, efficient and chemoselective procedures for the synthesis of borasiloxanes are thusb oth very important and highly desirable. [39][40][41] As such, efficient and chemoselective procedures for the synthesis of borasiloxanes are thusb oth very important and highly desirable.…”

“…[36][37][38] Si-O-B moiety,w hich is ac ore of poly(borasiloxane)s, is very interesting in terms of modernp olymer chemistry. [39][40][41] As such, efficient and chemoselective procedures for the synthesis of borasiloxanes are thusb oth very important and highly desirable. Conventional methodsf or their preparation are mainly based on the condensation between various boron and silicon derivatives.…”