Three-dimensional Interconnected Network Research Articles

Soft-template-assisted bottom-up fabrication of tunable porosity monolithic copper film for interconnection in microelectronics

Background: Third-generation devices offer superior attributes, necessitating advanced packaging materials for harsh operating environments. Incorporating 3D porous architectures to increase the reaction area further enhances the reaction rate, making transient liquid phase bonding an ideal interconnection process. Methods: Fabrication of monolithic porous Cu films using a bicontinuous microemulsion (BME) as a dynamic soft template is reported. The BME phase consists of interconnected three-dimensional networks of aqueous and oil phases, separated by surfactants and cosurfactants. This unique structure enables the selective electrodeposition of Cu exclusively within the aqueous region, preventing any unwanted reactions in the oil phase. Tunable porosity in the monolithic Cu film is achieved by adjusting the water to oil phase ratio in the BME. Significant findings: The Sn-plated porous Cu films exhibit low-temperature reflow capability while still maintaining high service temperatures. The utilization of the BME soft template offers a promising approach for fabricating monolithic Cu films with tunable porosity, providing flexibility in controlling the compositions and performance of interconnections. The compatibility of the BME with existing wafer deposition techniques makes it a viable and scalable solution for mass production. The electrodeposition of monolithic Cu arrays on Cu pillars demonstrates its potential applicability in advanced packaging technologies.

Highly tunable negative permittivity of carbon nanofiber/alumina metacomposites at different external temperatures

Effective and precise modulation of negative permittivity behavior still deserved further research. Herewith, alumina (Al2O3) metacomposites with various carbon nanofiber (CNF) contents were fabricated using hot-press sintering, and the effects of CNF content and external temperature on the electrical properties of metacomposites were investigated. As the CNF content increased, a three-dimensional interconnected CNF network was formed in the composites, resulting in the conversion of the impedance characteristic and the conductivity mechanism. The composites with CNF content of 2 wt% exhibited negative permittivity behavior, owing to the low-frequency plasma state of free electrons in the CNF conducting networks, which could be well simulated by the Drude model. Excellent electromagnetic shielding performance was observed in the composites with high CNF contents at Ku band, and shielding effectiveness reached more than 30 dB with a reflection-dominated mechanism. Furthermore, the temperature-dependences of the electrical properties of the composites were explored. Both the negative permittivity and conductivity of the composites increased with external temperature rising, which were mainly attributed to the changes in free electron concentration and mobility. It was worth noting that the values of negative permittivity varied very little, which provided an effective method for precise regulation of negative permittivity. This work not only enriched the adjustment method of negative permittivity but also helped to expand the application field of metacomposites.

Stretchable Thermoelectric Fibers with Three-Dimensional Interconnected Porous Network for Low-Grade Body Heat Energy Harvesting.

Electricity generation from body heat has garnered significant interest as a sustainable power source for wearable bioelectronics. In this work, we report stretchable n-type thermoelectric fibers based on the hybrid of Ti3C2Tx MXene nanoflakes and polyurethane (MP) through a wet-spinning process. The proposed fibers are designed with a 3D interconnected porous network to achieve satisfactory electrical conductivity (σ), thermal conductivity (κ), and stretchability simultaneously. We systematically optimize the thermoelectric and mechanical traits of the MP fibers and the MP-60 (with 60 wt % MXene content) exhibits a high σ of 1.25 × 103 S m-1, an n-type Seebeck coefficient of -8.3 μV K-1, and a notably low κ of 0.19 W m-1 K-1. Additionally, the MP-60 fibers possess great stretchability and mechanical strength with a tensile strain of 434% and a breaking stress of 11.8 MPa. Toward practical application, a textile thermoelectric generator is constructed based on the MP-60 fibers and achieves a voltage of 3.6 mV with a temperature gradient between the body skin and ambient environment, highlighting the enormous potential of low-grade body heat energy harvesting.

Design and preparation of hierarchical porous carbon-based materials with bionic “ant nest” structure for high performance asymmetric supercapacitors

Rational design of electrodes to broaden the working potential window is an attractive approach to improve the energy density of asymmetric supercapacitors. Herein, a simple non-solvent-induced phase separation method was used to construct a bionic "ant nest" three-dimensional hierarchical porous carbon (HPC) without any template, realizing a three-dimensional interlaced interconnection network structure similar to that of a natural ant nest, which adsorbs more ions through a larger accessible area and facilitates the bi-continuous transport of ions and electrons. Further, the aqueous asymmetric supercapacitor assembled with MnO2-modified HPC (HPC/MnO2) as the positive electrode and nitrogen-doped HPC (NHPC) as the negative electrode has an energy density as high as 21 Wh kg−1 at a power density of 410 W kg−1, and as high as 17 Wh kg−1 even at a power density of 13 kW kg−1. The device exhibits an excellent electrochemical performance over a potential window of 0–1.6 V.

Investigation of human hair keratin-based nanofibrous scaffold for skin tissue engineering application.

Keratin-based nanofibers were fabricated using the electrospinning technique, and their potential as scaffolds for tissue engineering was investigated. Keratin, extracted from the human hair, was blended with poly(vinyl alcohol) (PVA) in an aqueous medium. Morphological characterizations of the fabricated PVA-keratin nanofiber (PK-NF) random and aligned scaffolds performed using a scanning electron microscope (SEM) revealed the formation of uniform and randomly oriented nanofibers with an interconnected three-dimensional network structure. The mean diameter of the nanofibers ranged from 100 to 250nm. Functional groups and structural studies were done by infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. FTIR study suggested that PVA interacted with keratin by hydrogen bonding. Moreover, the in vitro cell culture study could suggest that PK-NF scaffolds were non-cytotoxic by supporting the growth of murine embryonic stem cells (ESCs), human keratinocytes (HaCaT), and dermal fibroblast (NHDF) cell lines. Further, the immunocytochemical characterization revealed the successful infiltration, adhesion, and growth of ESCs, HaCaT, and NHDF cells seeded on PK-NF scaffolds. However, there was no noteworthy difference observed concerning cell growth and viability irrespective of the random and aligned internal fibril arrangement of the PK-NF scaffolds. The infiltration and growth pattern of HaCaT and NHDF cells adjacent to each other in a 3D co-culture study mimicked that of epidermal and dermal skin cells and indeed underscored the potential of PK-NFs as a scaffold for skin tissue engineering.

In-situ strain characterization and stress analysis of SnO2@graphite@CNT electrodes for lithium-ion batteries by digital image correlation method

In this study, SnO2@graphite@CNT composite was synthesized by growing SnO2 nanoparticles within the interconnected three-dimensional network of graphite and carbon nanotubes using an acoustic chemistry method and a followed annealing treatment. As anode material for lithium-ion batteries, the composite exhibits high specific capacity and excellent cycling stability. The deformation behavior of the SnO2@graphite@CNT electrodes was in-situ monitored and recorded during discharge-charge process, and the strain fields onto the electrode surface was analyzed using digital image correlation technique. The dynamic evolution of plane stress in the electrode was evaluated by combining strain data with a mechano-electrochemical constitutive equation, and the contributions of mechanical and electrochemical parts to the plane stress also be discussed, respectively. The results provide valuable insights into the volume deformation behavior and mechano-electrochemical failure mechanism of SnO2-based electrodes for lithium-ion batteries.

Robust self-floating covalent organic framework/chitosan aerogels for the efficient removal of sulfamerazine

Covalent organic framework (COF) aerogels have attracted significant interest due to their broad range of potential applications. However, synthesizing COF aerogels with tailored structures and robust mechanical stability remains a formidable challenge. In this work, we present a double-cross-linking strategy to prepare a series of compressible COF/chitosan (COF/CS) aerogels under mild conditions. By harnessing chemical cross-linking and physical interactions, such as electrostatic and hydrogen bonding, ionic COF powders containing sulfonic acid groups (i.e., TpPa-SO3H) are immobilized and connected with CS, forming a three-dimensional interconnected network. Impressively, the ratio of COF to CS and the size of the COF/CS aerogels can be easily controlled by adjusting the processing parameters. The resulting COF/CS aerogels possess a highly porous structure and low density, enabling the aerogels to self-float and facilitating practical applications and recycling. Due to these remarkable characteristics, TpPa-SO3H/CS aerogel demonstrates excellent adsorption capacity, effectively removing sulfamerazine from aqueous solutions with an adsorption capacity of 102.5 mg·g−1. Moreover, the aerogel can be reused in three adsorption–desorption cycles without significant capacity loss. This proposed method offers a facile, eco-friendly, and scalable approach for producing highly compressive COF-based aerogels, thereby accelerating the practical utilization of COFs and contributing to environmental remediation.

Polyurethane foam-supported three-dimensional interconnected graphene nanosheets network encapsulated in polydimethylsiloxane to achieve significant thermal conductivity enhancement

Polyurethane foam-supported three-dimensional interconnected graphene nanosheets network encapsulated in polydimethylsiloxane to achieve significant thermal conductivity enhancement

3D bioprinted hydrogel/polymer scaffold with factor delivery and mechanical support for growth plate injury repair.

Introduction: Growth plate injury is a significant challenge in clinical practice, as it could severely affect the limb development of children, leading to limb deformity. Tissue engineering and 3D bioprinting technology have great potential in the repair and regeneration of injured growth plate, but there are still challenges associated with achieving successful repair outcomes. Methods: In this study, GelMA hydrogel containing PLGA microspheres loaded with chondrogenic factor PTH(1-34) was combined with BMSCs and Polycaprolactone (PCL) to develop the PTH(1-34)@PLGA/BMSCs/GelMA-PCL scaffold using bio-3D printing technology. Results: The scaffold exhibited a three-dimensional interconnected porous network structure, good mechanical properties, biocompatibility, and was suitable for cellchondrogenic differentiation. And a rabbit model of growth plate injury was appliedto validate the effect of scaffold on the repair of injured growth plate. The resultsshowed that the scaffold was more effective than injectable hydrogel in promotingcartilage regeneration and reducing bone bridge formation. Moreover, the addition ofPCL to the scaffold provided good mechanical support, significantly reducing limbdeformities after growth plate injury compared with directly injected hydrogel. Discussion: Accordingly, our study demonstrates the feasibility of using 3D printed scaffolds for treating growth plate injuries and could offer a new strategy for the development of growth plate tissue engineering therapy.

Salt template-assisted construction of three-dimensional interconnected network in thermally conductive EP/PVDF/NiCo@GNP composites

In this study, graphene nanoplatelets (GNP) and nickel–cobalt (NiCo) alloy were adopted as reinforcing materials to prepare epoxy (EP) resin-based composites. NiCo particles were able to achieve uniform anchoring on GNPs’ surface under the electrostatic force due to the successful introduction of oxygen defects on GNPs. With the synergistic effect of adhesive PVDF and salt particles, the system with three-dimensionally (3D) interconnected network was successfully constructed. Benefit from the formation of mechanically stable and efficient heat conduction paths, the thermal conductivity (TC) of the EP/PVDF/NiCo@GNP composite reached 1.077 W⋅m−1⋅K−1 at a filler volume fraction of 6.82 vol%, while the counterpart’s storage modulus (E’) was up to 3.22 GPa. In addition, a scaling formula was quantitatively proposed to correlate TC with E’, and the perfect agreement between the theoretical prediction and experimental data clarified the underlying mechanism of the relationship between phonons transport and stress transfer within a system with 3D ordered structures. The establishment of relationship between AHR (average heating rate) and TC made it possible to further predict TC of composites based upon the infrared thermal imaging (ITI) data. The as-prepared GNP composites show good application prospects as thermal management materials which need to experience thermally mechanical deformation.

Efficient fabrication of poly(vinylidene fluoride)/graphene composite actuators with robust superhydrophobicity and excellent photothermal performance for controllable light-driven motion

The Marangoni effect has garnered significant interest as a promising method for non-contact, remote-controlled actuation. Despite the numerous advantages it offers, the high cost and complex fabrication procedures associated with the technology have limited its widespread application. To address these limitations, an industrialized polymer processing strategy that combines melt blending and hydrophobic modification is proposed for the large-scale and cost-effective production of lightweight poly(vinylidene fluoride)/graphene nanosheets foam with a three-dimensional interconnected network. The foam displays excellent superhydrophobic properties, including a contact angle of 155 ± 2° and a rolling angle of 7 ± 3°. Furthermore, the foam is durable under a variety of conditions, including dynamic impact, high temperatures, acidic and alkaline environments, knife scratching, abrasion damage, and tape peeling. Additionally, the foam displays stable photothermal conversion performance due to the uniform dispersion of graphene nanosheets throughout the polymer matrix. When used as a light-driven actuator, the foam demonstrates the ability to achieve on-demand driving as well as swimming route planning at the water–air interface. The proposed method offers a promising solution for the efficient fabrication of light-driven actuators that are both adapted to practical applications and resistant to external damages.

Porous structure of fixed sulfur and networked electronic channels in three-dimensional skeletal structure of polyaniline and MOF-derived materials

Lithium-sulfur batteries (LSBs) are favored for their high specific capacity and energy density, but they have problems, such as electrode volume expansion and poor electrical conductivity, that need to be solved. In this work, a three-dimensional (3D) interconnection network structure (3CPC) material was designed and synthesized from the composite of polyaniline (PANI) and metal–organic-skeleton-derived nitrogen carbon (NC). PANI conductive fiber acts as a bridge between NC and insulating sulfur to promote electron transfer. A large number of mesopores and micropores in the 3D spatial network structure effectively fixed sulfur. Results show that the 3CPC@S cathode materials have excellent electrochemical properties. The initial discharge-specific capacity of the 3CPC@S cathode material reached 1220.1 mAh g−1 at a current density of 0.1 C. Its reversible capacity was 1018.7 mAh g−1 after 100 cycles, corresponding to a capacity retention rate of 83.5%. The material frame was used to provide electronic channels, and the physical structure was combined to carry out sulfur fixation to improve the electrochemical performance of the cathode material. This method provides a new idea for improving the volume expansion and conductivity of LSB electrode.

Facile fabrication of Zr-based metal–organic framework/Ketjen black-carbon nanotubes composite sensor for highly sensitive detection of methyl parathion

A novel methyl parathion (MP) electrochemical sensor was fabricated from the multifunctional composite of Zr-based metal–organic framework (UiO-66) and Ketjen black-carbon nanotubes (KB-CNTs), which achieved the sensitive detection of MP in food samples. For the UiO-66/KB-CNTs composite, Zr-based UiO-66 with Zr-OH groups possessed good affinity for phosphate groups on methyl parathion molecules, which enhanced the selective recognition and enrichment capability towards MP, and KB-CNTs possessed three-dimensional interconnected carbon conductive network with synergistic point-line carbon conductive contact, which showed excellent electrical conductivity. Moreover, KB with pearl chain-like structure and more conductive contact points realized the full contact between KB-CNTs and UiO-66 with Zr-OH groups. The fabricated UiO-66/KB-CNTs/GCE sensor showed good MP detection performance with low limit of detection of 1.53 nM in linear MP concentration range of 0.005–12 µM. Moreover, the fabricated sensor showed good repeatability, reproducibility, and selectivity. A good practical feasibility can be achieved at the UiO-66/KB-CNTs/GCE sensor for the detection of MP in grape juice and apple juice samples (Recovery rate: 96.14–102.93, relative standard deviation: 2.17%-4.95%).

Hierarchical Pt/NiCo2O4 nanosheets decorated carbon nanofibers for room-temperature catalytic formaldehyde oxidation

Room-temperature catalytic formaldehyde (HCHO) oxidation is regarded as the most promising way for constant and oxidative removal of indoor HCHO. Herein, carbon nanofibers (CNF) with three-dimensional (3D) interconnection network structure decorated with Pt/NiCo2O4 alloy nanosheets (Pt/NiCo2O4/CNF) were fabricated in-situ to catalyze the oxidation of HCHO at ambient temperature. The presence of CNF helps to inhibit the aggregation of NiCo2O4 nanosheets, expose more active sites and form a hierarchically porous structure, which is conducive to the dispersion of platinum nanoparticles (NPs) and the diffusion of reactants. Besides, oxygen vacancies from Pt-loading process ensure abundant active oxygen species, which are beneficial to HCHO oxidation. Moreover, CNF with microporous structure can strongly adsorb HCHO, rapidly reduce the concentration of HCHO in air and increase its concentration near Pt/NiCo2O4, thus accelerating the formaldehyde oxidation reaction. At Pt content as low as 0.5 wt%, Pt/NiCo2O4/CNF exhibits superior HCHO oxidation activity, and conversion of 92.4% can be achieved within 60 min due to the combination of adsorption and oxidation. This work may shed light on fabricating CNF-based 3D catalysts for the practical application of indoor HCHO elimination.

Porous graphitic carbon nitride nanosheets with three-dimensional interconnected network as electrode for supercapacitors

Graphitic carbon nitride material with hierarchical porous structure and high doping level has been reported to exhibit superior capacitive properties due to the facilitated electrolyte migration and redox process. In this work, porous graphitic carbon nitride layers (UMCN-A1.25) with typical three-dimensional (3D) network were prepared through a facile calcination process. For its preparation, NH4HCO3 was used as the pore generator and glucose was used as the carbon precursor. Urea and melamine, which worked as the binary precursors for sacrificial template, played important roles in the formation of the final 3D interconnected structure. The hierarchical pore structure and high nitrogen-doping level endow UMCN-A1.25 with high specific capacitances (520 F g−1 at 0.1 A g−1 and 219.4 F g−1 at 20 A g−1) and stable charge-discharge behavior with no capacitance declination after 10,000 cyclic tests. This work proposed an efficient route for the construction of inter-connected carbon nitride layers, and also revealed the importance of both lamellar morphology and interwoven structure for the acquisition of high capacitive properties.

Formation of MXene-Derived/NiCoFe-LDH Heterostructures for Supercapacitor Applications.

In this study, MXene-derived/NiCoFe-LDH heterostructures with three-dimensional interconnected porous network microstructures were prepared, leveraging the excellent electrical conductivity and growth platform provided by the MXene material. The remarkable specific capacitance of metal oxides was fully exploited. The composite exhibited high specific capacitance and excellent stability, with a specific capacitance of 1305 F g-1 at 1 A g-1 and a capacitance of 85.7% of the initial performance after 6000 charge/discharge tests at 10 A g-1. A two-electrode assembly was constructed using activated carbon as the negative electrode material corresponding to 49.5 Wh kg-1 at 800 W kg-1, indicating that the electrodes could achieve rapid charge/discharge. The findings of this study indicate that the composite material comprising LDH/MXene has significant potential for supercapacitor applications.

Lignin derived porous carbon with favorable mesoporous contributions for highly efficient ionic liquid-based supercapacitors

Lignin and its derivatives hold great potential in developing high performance porous carbon materials for supercapacitors due to the versatile features of high carbon content, abundant multifunctional groups, low cost, and environmental benefits. Unfortunately, their derived porous carbon generally has the features of unfavorable microporous-dominated morphologies and low specific surface area (SSA) attributed from the highly-branched structure of lignin, which are hardly suitable for the supercapacitors with ionic liquid (IL) electrolyte, leading to poor energy density and rate capability. Herein, porous carbon materials with desirable mesoporous contributions from sodium lignosulphonate are designed via a facile template method. Such rich mesoporisity carbon materials not only possess with three-dimensional interconnected network, large SSA, as well as favorable pore size distribution for accelerated ion and electron mass transfer, but also feature low heteroatom content for high electrochemical stability. Consequently, the optimal electrode exhibits a high capacitance of 166 F/g at 0.5 A/g, superior rate performance (59 Wh/kg at 59 kW/kg), as well as impressive cycle life with good capacitance retention of 93.1% in EMIBF4 electrolytes. The present work opens a new avenue to design porous carbon materials with high mesopore properties from lignin for effective compatibility with IL electrolyte in high-performance supercapacitors.

A 3D Corncob-based interfacial solar evaporator enhanced by environment energy with salt-rejecting and anti-corrosion for seawater distillation

Biomass-derived, carbon converted from renewable biomass materials via the carbonization process, has been widely investigated for interfacial solar evaporators and is deemed a promising choice for solar desalination. However, salt accumulation at the evaporation interface is a great challenge. Studies show that the surface wetting and antifouling ability of carbonized-biomass, affects solar absorption, water supply, and water evaporation. In this paper, a simple two-step strategy completely different from carbonization is proposed for efficient solar evaporation and seawater desalination. In this regard, an interfacial solar evaporator is prepared based on the corn cob. The evaporator makes the best use of the raw three-dimensional interconnected fiber network structure, which extremely promotes the collection of solar energy, sufficient water supply, and vapor escape at the evaporation interface. Owing to the decrease in evaporation enthalpy and drawing energy from the environment, the evaporation rate and the photothermal conversion efficiency of proposed the evaporator reached 1.68 kg·m−2·h−1 and 99.32 % under solar irradiation intensity of 1 kW·m−2, respectively. The performance of the proposed scheme was investigated under various salinity levels and a great salt-rejecting and anti-corrosion performance was achieved. This simple strategy is a promising candidate for preparing biomass-based interfacial solar evaporators in practical applications.

A natural juncus-derived three-dimensional interconnected tubular carbon network decorated with tiny solid-solution metal sulfide nanoparticles achieves efficient sodium storage

Juncus-derived three-dimensional interconnected tubular carbon network decorated with tiny solid-solution metal sulfide nanoparticles favorably affords affluent active sites and porous channels, thus endowing superior sodium-storage performance.

Application of a three dimensional polyethyleneimine functionalized graphene oxide aerogel as an adsorbent for the determination of phytohormones in ginseng.

Aerogels have attracted considerable attention in sample pretreatment for their outstanding properties, such as the unique porous structure, large surface area and abundant modifiable active sites. The present research reports a three-dimensional interconnected porous network aerogel (PEI-AGO) manufactured based on graphene oxide (GO), polyethyleneimine (PEI) and agar as basic materials through a vacuum freeze-drying treatment. The PEI-AGO aerogel exhibits great potential as a solid phase extraction adsorbent for the selective purification of six endogenous plant hormones in conjunction with high performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-MS). Several factors affecting the extraction efficiency were investigated. Under the optimized extraction conditions, a wide linear range of 0.5-100 ng mL-1 with a good linearity (r > 0.9934) was observed. Low limits of detection (LODs) and limits of quantification (LOQs) were obtained in the range of 0.032-0.155 ng mL-1 and 0.107-0.518 ng mL-1, respectively. Furthermore, the relative recoveries for spiked ginseng samples exhibited remarkable consistency, ranging from 90.2% to 117.6%, with a relative standard deviation (RSD) of ≤9.4% (n = 3). In summary, PEI-AGO has proven to be an effective adsorbent for the pretreatment and enrichment of phytohormones which can be used for the determination of trace endogenous acidic plant hormones in ginseng leaves.