In Situ Construction of Polypyrrole–Silver Composite Conductive Phase in High‐Performance Polyimide Sponge and Study of Sensing Behavior Under Microstress

Advanced Engineering Materials, Год журнала: 2024, Номер unknown

Опубликована: Окт. 31, 2024

Composites comprising conductive polymers and metal particles have garnered considerable interest in sensor technology due to their excellent electrical conductivity. However, producing controllable pressure sensors that retain high sensitivity under microstress remains challenging. Polyimide (PI) sponge exhibits chemical thermal stability a porous structure facilitates deformation low stress levels results good external forces. Herein, polymer–metal composite phase, polypyrrole–silver (PPy–Ag), is directly fabricated on the PI surface through incipient network conformal growth. This method ensures PPy–Ag maintains optimal performance within its original temperature range, thereby enhancing detection at levels. The maximum conductivity of PPy–Ag/PI sponge‐based flexible piezoresistive 2.42 × 10 −4 S m −1 , recorded 16.31 kPa range 0–80 Pa. After undergoing 1000 compression cycles, commendable reproducibility.

Язык: Английский

Formation Mechanism of Polypyrrole-Coated Hollow Glass Microspheres (PPy@HGMs) Composite Powder

Materials, Год журнала: 2024, Номер 17(22), С. 5595 - 5595

Опубликована: Ноя. 15, 2024

Coating conductive nanoparticles onto the surface of hollow glass microspheres (HGMs) is essential for broadening their applications. However, low density and high specific area HGM powders, along with thin walls cavity shells poor adhesion, pose challenges uniform attachment functional particles. In this study, we developed a novel integrated process that combines flotation, hydroxylation, amination pretreatment HGMs in situ polymerization to achieve coating polypyrrole (PPy) on HGMs. We explored corresponding growth mechanism. Our findings indicate amount coating, particle size, uniformity PPy are significantly influenced by time, as well microspheres/pyrrole feedstock ratio. The resulted encapsulation spherical PPy, average size PPy-coated (PPy@HGMs) increasing 14.60% compared original elemental nitrogen PPy@HGMs primarily exists form C-N N-H bonds. This study demonstrates groups engage chemical bonding interactions molecules. Mechanistic analysis reveals hydroxyl amino enriched pretreated serve activation centers, facilitating enrichment pyrrole monomers promoting chain conjugated through nucleophilic electrophilic subamino ring. Additionally, reaction between Lewis acid properties Lewis-type electron-donating KH550 fosters strong formation robust interface.

Язык: Английский

Ultralight and Anisotropic Heterocyclic Para-aramid Nanofiber/Reduced Graphene Oxide Composite Aerogel for Efficient Thermal Insulation and Flame Retardancy

Chinese Journal of Polymer Science, Год журнала: 2024, Номер unknown

Опубликована: Дек. 11, 2024

Язык: Английский