Thermally Conductive 3D-Printed Carbon-Nanotube-Filled Polymer Nanocomposites for Scalable Thermal Management

Thermal transportation in a preferred direction is desirable and important for addressing thermal management issues. With the merits of high thermal conductivity, good chemical stability, and desirable mechanical properties, carbon nanotubes (CNTs) have a great potential for wide applications in heat dissipation devices. The combination of 3D printing and CNTs can enable unlimited possibilities for hierarchically aligned structural programming. We report the formation of through-plane aligned multiwalled CNT (MWCNT)-filled polylactic acid (PLA) nanocomposites by 3D printing. The as-printed vertically (or through-plane) aligned structure demonstrates a through-plane thermal conductivity (k⊥) of ∼0.575 W/(mK) at 20 wt % MWCNT content, which is around 2.64 times that of a horizontally aligned structure (∼0.218 W/(mK)) and around 5.87 times that of neat PLA (∼0.098 W/(mK)) at 35 °C. Infrared thermal imaging performed on 3D-printed MWCNT/PLA heat sink verified the superior performance of the nanocomposite compared to that of the matrix polymer. In this study, we achieved the manufacturing of MWCNT/PLA with a high filler loading and a significant improvement in thermal conductivity simultaneously. This work paves the way to develop 3D-printed carbon filler-reinforced polymer composites for thermal-related applications such as heat sinks or thermal radiators

Three-Dimensional Printable High-Temperature and High-Rate Heaters

High temperature heaters are ubiquitously used in materials synthesis and device processing. In this work, we developed three-dimensional (3D) printed reduced graphene oxide (RGO)-based heaters to function as high-performance thermal supply with high temperature and ultrafast heating rate. Compared with other heating sources, such as furnace, laser, and infrared radiation, the 3D printed heaters demonstrated in this work have the following distinct advantages: (1) the RGO based heater can operate at high temperature up to 3000 K because of using the high temperature-sustainable carbon material; (2) the heater temperature can be ramped up and down with extremely fast rates, up to ∼20 000 K/second; (3) heaters with different shapes can be directly printed with small sizes and onto different substrates to enable heating anywhere. The 3D printable RGO heaters can be applied to a wide range of nanomanufacturing when precise temperature control in time, placement, and the ramping rate are important

Three-Dimensional Printable High-Temperature and High-Rate Heaters

High temperature heaters are ubiquitously used in materials synthesis and device processing. In this work, we developed three-dimensional (3D) printed reduced graphene oxide (RGO)-based heaters to function as high-performance thermal supply with high temperature and ultrafast heating rate. Compared with other heating sources, such as furnace, laser, and infrared radiation, the 3D printed heaters demonstrated in this work have the following distinct advantages: (1) the RGO based heater can operate at high temperature up to 3000 K because of using the high temperature-sustainable carbon material; (2) the heater temperature can be ramped up and down with extremely fast rates, up to ∼20 000 K/second; (3) heaters with different shapes can be directly printed with small sizes and onto different substrates to enable heating anywhere. The 3D printable RGO heaters can be applied to a wide range of nanomanufacturing when precise temperature control in time, placement, and the ramping rate are important

3D-Printed Parahydrophobic Functional Textile with a Hierarchical Nanomicroscale Structure

Functional textiles with superhydrophobicity and high adhesion to water, called parahydrophobic, are attracting increasing attention from industry and academia. The hierarchical (micronanoscale) surface patterns in nature provide an excellent reference for the manufacture of parahydrophobic functional textiles. However, the replication of the complex parahydrophobic micronanostructures in nature exceeds the ability of traditional manufacturing strategies, which makes it difficult to accurately manufacture controllable nanostructures on yarn and textiles. Herein, a two-photon femtosecond laser direct writing strategy with nanoscale process capability was utilized to accurately construct the functional parahydrophobic yarn with a diameter of 900 μm. Inspired by rose petals, the parahydrophobic yarn is composed of a hollow round tube, regularly arranged micropapillae (the diameter is 109 μm), and nanofolds (the distance is 800 nm) on papillae. The bionic yarn exhibited a superior parahydrophobic behavior, where the liquid droplet not only was firmly adhered to the bionic yarn at an inverted angle (180°) but also presented as spherical on the yarn (the maximum water contact angle is 159°). The fabric woven by the bionic yarn also exhibited liquid droplet-catching ability even when tilted vertically or turned upside down. Based on the excellent parahydrophobic function of bionic yarn, we demonstrated a glove that has very wide application potential in the fields of water droplet-based transportation, manipulation, microreactors, microextractors, etc

Carbon Welding by Ultrafast Joule Heating

Carbon nanomaterials exhibit outstanding electrical and mechanical properties, but these superior properties are often compromised as nanomaterials are assembled into bulk structures. This issue of scaling limits the use of carbon nanostructures and can be attributed to poor physical contacts between nanostructures. To address this challenge, we propose a novel technique to build a 3D interconnected carbon matrix by forming covalent bonds between carbon nanostructures. High temperature Joule heating was applied to bring the carbon nanofiber (CNF) film to temperatures greater than 2500 K at a heating rate of 200 K/min to fuse together adjacent carbon nanofibers with graphitic carbon bonds, forming a 3D continuous carbon network. The bulk electrical conductivity of the carbon matrix increased four orders of magnitude to 380 S/cm with a sheet resistance of 1.75 Ω/sq. The high temperature Joule heating not only enables fast graphitization of carbon materials at high temperature, but also provides a new strategy to build covalently bonded graphitic carbon networks from amorphous carbon source. Because of the high electrical conductivity, good mechanical structures, and anticorrosion properties, the 3D interconnected carbon membrane shows promising applications in energy storage and electrocatalysis fields

3D-Printed Parahydrophobic Functional Textile with a Hierarchical Nanomicroscale Structure

Functional textiles with superhydrophobicity and high adhesion to water, called parahydrophobic, are attracting increasing attention from industry and academia. The hierarchical (micronanoscale) surface patterns in nature provide an excellent reference for the manufacture of parahydrophobic functional textiles. However, the replication of the complex parahydrophobic micronanostructures in nature exceeds the ability of traditional manufacturing strategies, which makes it difficult to accurately manufacture controllable nanostructures on yarn and textiles. Herein, a two-photon femtosecond laser direct writing strategy with nanoscale process capability was utilized to accurately construct the functional parahydrophobic yarn with a diameter of 900 μm. Inspired by rose petals, the parahydrophobic yarn is composed of a hollow round tube, regularly arranged micropapillae (the diameter is 109 μm), and nanofolds (the distance is 800 nm) on papillae. The bionic yarn exhibited a superior parahydrophobic behavior, where the liquid droplet not only was firmly adhered to the bionic yarn at an inverted angle (180°) but also presented as spherical on the yarn (the maximum water contact angle is 159°). The fabric woven by the bionic yarn also exhibited liquid droplet-catching ability even when tilted vertically or turned upside down. Based on the excellent parahydrophobic function of bionic yarn, we demonstrated a glove that has very wide application potential in the fields of water droplet-based transportation, manipulation, microreactors, microextractors, etc

Carbon Welding by Ultrafast Joule Heating

Carbon nanomaterials exhibit outstanding electrical and mechanical properties, but these superior properties are often compromised as nanomaterials are assembled into bulk structures. This issue of scaling limits the use of carbon nanostructures and can be attributed to poor physical contacts between nanostructures. To address this challenge, we propose a novel technique to build a 3D interconnected carbon matrix by forming covalent bonds between carbon nanostructures. High temperature Joule heating was applied to bring the carbon nanofiber (CNF) film to temperatures greater than 2500 K at a heating rate of 200 K/min to fuse together adjacent carbon nanofibers with graphitic carbon bonds, forming a 3D continuous carbon network. The bulk electrical conductivity of the carbon matrix increased four orders of magnitude to 380 S/cm with a sheet resistance of 1.75 Ω/sq. The high temperature Joule heating not only enables fast graphitization of carbon materials at high temperature, but also provides a new strategy to build covalently bonded graphitic carbon networks from amorphous carbon source. Because of the high electrical conductivity, good mechanical structures, and anticorrosion properties, the 3D interconnected carbon membrane shows promising applications in energy storage and electrocatalysis fields

3D-Printed Parahydrophobic Functional Textile with a Hierarchical Nanomicroscale Structure

Functional textiles with superhydrophobicity and high adhesion to water, called parahydrophobic, are attracting increasing attention from industry and academia. The hierarchical (micronanoscale) surface patterns in nature provide an excellent reference for the manufacture of parahydrophobic functional textiles. However, the replication of the complex parahydrophobic micronanostructures in nature exceeds the ability of traditional manufacturing strategies, which makes it difficult to accurately manufacture controllable nanostructures on yarn and textiles. Herein, a two-photon femtosecond laser direct writing strategy with nanoscale process capability was utilized to accurately construct the functional parahydrophobic yarn with a diameter of 900 μm. Inspired by rose petals, the parahydrophobic yarn is composed of a hollow round tube, regularly arranged micropapillae (the diameter is 109 μm), and nanofolds (the distance is 800 nm) on papillae. The bionic yarn exhibited a superior parahydrophobic behavior, where the liquid droplet not only was firmly adhered to the bionic yarn at an inverted angle (180°) but also presented as spherical on the yarn (the maximum water contact angle is 159°). The fabric woven by the bionic yarn also exhibited liquid droplet-catching ability even when tilted vertically or turned upside down. Based on the excellent parahydrophobic function of bionic yarn, we demonstrated a glove that has very wide application potential in the fields of water droplet-based transportation, manipulation, microreactors, microextractors, etc

3D-Printed Parahydrophobic Functional Textile with a Hierarchical Nanomicroscale Structure

Functional textiles with superhydrophobicity and high adhesion to water, called parahydrophobic, are attracting increasing attention from industry and academia. The hierarchical (micronanoscale) surface patterns in nature provide an excellent reference for the manufacture of parahydrophobic functional textiles. However, the replication of the complex parahydrophobic micronanostructures in nature exceeds the ability of traditional manufacturing strategies, which makes it difficult to accurately manufacture controllable nanostructures on yarn and textiles. Herein, a two-photon femtosecond laser direct writing strategy with nanoscale process capability was utilized to accurately construct the functional parahydrophobic yarn with a diameter of 900 μm. Inspired by rose petals, the parahydrophobic yarn is composed of a hollow round tube, regularly arranged micropapillae (the diameter is 109 μm), and nanofolds (the distance is 800 nm) on papillae. The bionic yarn exhibited a superior parahydrophobic behavior, where the liquid droplet not only was firmly adhered to the bionic yarn at an inverted angle (180°) but also presented as spherical on the yarn (the maximum water contact angle is 159°). The fabric woven by the bionic yarn also exhibited liquid droplet-catching ability even when tilted vertically or turned upside down. Based on the excellent parahydrophobic function of bionic yarn, we demonstrated a glove that has very wide application potential in the fields of water droplet-based transportation, manipulation, microreactors, microextractors, etc

3D-Printed Parahydrophobic Functional Textile with a Hierarchical Nanomicroscale Structure

Functional textiles with superhydrophobicity and high adhesion to water, called parahydrophobic, are attracting increasing attention from industry and academia. The hierarchical (micronanoscale) surface patterns in nature provide an excellent reference for the manufacture of parahydrophobic functional textiles. However, the replication of the complex parahydrophobic micronanostructures in nature exceeds the ability of traditional manufacturing strategies, which makes it difficult to accurately manufacture controllable nanostructures on yarn and textiles. Herein, a two-photon femtosecond laser direct writing strategy with nanoscale process capability was utilized to accurately construct the functional parahydrophobic yarn with a diameter of 900 μm. Inspired by rose petals, the parahydrophobic yarn is composed of a hollow round tube, regularly arranged micropapillae (the diameter is 109 μm), and nanofolds (the distance is 800 nm) on papillae. The bionic yarn exhibited a superior parahydrophobic behavior, where the liquid droplet not only was firmly adhered to the bionic yarn at an inverted angle (180°) but also presented as spherical on the yarn (the maximum water contact angle is 159°). The fabric woven by the bionic yarn also exhibited liquid droplet-catching ability even when tilted vertically or turned upside down. Based on the excellent parahydrophobic function of bionic yarn, we demonstrated a glove that has very wide application potential in the fields of water droplet-based transportation, manipulation, microreactors, microextractors, etc