The electrical conductive behaviours of polymer-based three-phase composites prepared by spatial confining forced network assembly

Guo

J of Applied Polymer Sci

et al. 2021

In order to meet the heat dissipation requirements of electronic equipment, a variety of methods for preparing thermally conductive polymer composites have been proposed. In this article, highly thermal conductive polydimethylsiloxane (PDMS) composites were prepared by combining the spatial confining forced network assembly (SCFNA) method with adding rigid particles (RPs). The orthogonal experiments were designed to verify the effects of short carbon fiber (SCF) content, glass bubble (GB) content, GB particle size and composite thickness on the thermal conductivity (λ) of SCF-GB/PDMS composite. In addition, the λ and shapes of different RPs (including GB, SiO 2 , AlN, glass fiber [GF]) also play vital roles in λ enhancements of SCF-RP/PDMS composites. The mechanical properties of SCF-RP/PDMS composites were different with various RPs contents, and the SCF-GB/PDMS composite presented the largest elongation at break (70%) and the best mechanical flexibility. The SCF-GB/PDMS composite with a low GB content of 5 vol% can not only greatly improve the λ, but also ensure its excellent mechanical properties.

mentioning

confidence: 90%

Influence of rigid particles on thermal conductivity enhancement of polydimethylsiloxane composite during spatial confining forced network assembly

Guo

J of Applied Polymer Sci

et al. 2021

“…Previous researches have already paid a lot of attention on the influences of size, shape, filling content, and surface modification of single or hybrid thermal conductive fillers on TCs of polymer composites. [35][36][37] The effective promotion of polymer matrix with higher TC on the property enhancement of polymer composite has also been systemically investigated. [38] However, high filling contents would lead to significant decrease of processability and mechanical property of polymer composites, different processing methods (e.g.…”

Section: Introductionmentioning

confidence: 99%

The Contribution of Conductive Network Conversion in Thermal Conductivity Enhancement of Polymer Composite: A Theoretical and Experimental Study

Sun¹,

Zhang²,

Du³

et al. 2021

ES Mater. Manuf.

In view of thermal conductive network (TCN) conversion from high thermal dissipation to low thermal dissipation, a new theory of thermal conductivity (TC) enhancement was proposed in this paper. The TC enhancement effect was greatly limited due to the formation of an uncompacted self-assembly network in the composites prepared by traditional compounding methods. In order to achieve the goal of TCN conversion from high thermal dissipation to low thermal dissipation, we combined the TCN densification through space confining forced network assembly (SCFNA) with adding rigid particles. A composite system of polydimethylsiloxane/short carbon fiber/glass bubble (PDMS/SCF/GB) was selected as the modelling object and used to perform verification experiments. On the basis of Nan model, the TCN conversion mathematical model of TC prediction was established. The effects of volume fraction, thermal boundary resistance, thermal contact resistance, aspect ratio and distribution state of fillers on the effective thermal conductivity (ETC) of this PDMS composite were all systematically studied and discussed. In order to verify the accuracy of the model established to predict the TC of PDMS/SCF/GB composite during TCN conversion, a series of experiments were carried out to compare with the model results.

“…The products obtain from the processing methods that belong to the first type are also known as conductive polymer composites (CPCs). Melt blending, sol–gel method, ice‐templating, self‐assembling, electrospinning, forced infiltration, spatial confining forced network assembly (SCFNA), [ 38–42 ] etc., are all representative methods in this type. However, the CPCs always present limited sensitivity as flexible/wearable sensors with higher filler consumption.…”

Section: Introductionmentioning

confidence: 99%

Scalable Fabrication of Flexible Single‐Layer Strain and Double‐Layer Pressure Sensors by Inkjet Printing for Subtle Vibration Detection

Gai

et al. 2021

Adv Materials Inter

Flexible sensors have attracted tremendous attentions in subtle force/vibration detection, human motion/health monitoring, and other related application fields. Although various sensors are developed to meet this growing demand, it is still a huge challenge to prepare satisfactory sensors with ultrahigh sensitivity and superior stability. In this work, a double‐layer flexible sensor is successfully prepared via an efficient and designable inkjet printing approach. Metallic silver layers are deposited onto polyurethane acrylate substrates with or without microstructures to form the flexible electrodes. The combination of a flat electrode and a microstructured electrode finally becomes a durable double‐layer flexible sensor with ultrahigh sensitivity and superior stability. Besides, the flexible flat electrodes can also be applied as single‐layer sensors. An ultrahigh sensitivity (maximum gauge factor of >1100), favorable durability (>1000 cycles), and fast response time (≈90 ms) are achieved simultaneously in a flat single‐layer sensor, while the combined double‐layer sensor presents quick response capability to small pressures (≈250 Pa). Moreover, these single‐layer and double‐layer sensors can monitor a variety of physiological signals (e.g., human pulse waveform, breathing behavior, and voice recognition), indicating their promising applications in wearable electronics.