Fabrication Of Architectures Research Articles

Fabrication of impermeable dense architecture containing covalently stitched graphene oxide/boron nitride hybrid nanofiller reinforced semi-interpenetrating network for hydrogen gas barrier applications

The GO-BN hybrid nanofiller reinforced TPU/epoxy semi-interpenetrating network provided an excellent H2barrier coating along with superior adhesion for the nylon 6 based compressed H2storage vessels.

The delamination behaviour of Vectran/Epoxy composites having a novel Non-Crimp Fabric architecture

The Mode I and Mode II Interlaminar Fracture Toughness (IFT) of Vectran/Epoxy composite material were investigated using the Double Cantilever Beam (DCB) and 4 End Notched Flexure (4ENF) methods, respectively. Due to the relatively low compressive strength of Vectran material (<10% of its tensile properties), specimens were hybridised by over wrapping Vectran/Epoxy with T800s/M21 to prevent compressive failure during testing. Experimental results were then simulated using the non-linear Finite Element Method (FEM) package, LS-Dyna. Fractographic studies were also conducted to understand the mechanism of failure and factors influencing it.

Recent Trends in Synthesis and Applications of Porous MXene Assemblies: A Topical Review

MXene possesses high conductivity, excellent hydrophilicity, rich surface chemistry, hence holds great potential in various applications. However, MXene materials have low surface area utilization due to the agglomeration of ultrathin nanosheets. Assembling 2D MXene nanosheets into 3D multi-level architectures is an effective way to circumvent this issue. Incorporation of MXene with other nanomaterials during the assembly process could rationally tune and tailor the specific surface area, porosity and surface chemistry of the MXene assemblies. The complementary and synergistic effect between MXene and nanomaterials could expand their advantages and make up for their disadvantages, thus boost the performance of 3D porous MXene composites. Herein, we summarize the recent progress in fabrication of porous MXene architectures from 2D to 3D, and also discuss the potential applications of MXene nanostructures in energy harvesting systems, sensing, electromagnetic interference shielding, water purification and photocatalysis.

Development and Characterization of Gelatin-Norbornene Bioink to Understand the Interplay between Physical Architecture and Micro-Capillary Formation in Biofabricated Vascularized Constructs.

The principle challenge for engineering viable, cell-laden hydrogel constructs of clinically-relevant size, is rapid vascularization, in order to moderate the finite capacity of passive nutrient diffusion. A multiscale vascular approach, with large open channels and bulk microcapillaries may be an admissible approach to accelerate this process, promoting overall pre-vascularization for long-term viability of constructs. However, the limited availability of bioinks that possess suitable characteristics that support both fabrication of complex architectures and formation of microcapillaries, remains a barrier to advancement in this space. In this study, gelatin-norbornene (Gel-NOR) is investigated as a vascular bioink with tailorable physico-mechanical properties, which promoted the self-assembly of human stromal and endothelial cells into microcapillaries, as well as being compatible with extrusion and lithography-based biofabrication modalities. Gel-NOR constructs containing self-assembled microcapillaries are successfully biofabricated with varying physical architecture (fiber diameter, spacing, and orientation). Both channel sizes and cell types affect the overall structural changes of the printed constructs, where cross-signaling between both human stromal and endothelial cells may be responsible for the reduction in open channel lumen observed over time. Overall, this work highlights an exciting three-way interplay between bioink formulation, construct design, and cell-mediated response that can be exploited towards engineering vascular tissues.

Fluorescent Biosensors Based on Silicon Nanowires.

Nanostructures are arising as novel biosensing platforms promising to surpass current performance in terms of sensitivity, selectivity, and affordability of standard approaches. However, for several nanosensors, the material and synthesis used make the industrial transfer of such technologies complex. Silicon nanowires (NWs) are compatible with Si-based flat architecture fabrication and arise as a hopeful solution to couple their interesting physical properties and surface-to-volume ratio to an easy commercial transfer. Among all the transduction methods, fluorescent probes and sensors emerge as some of the most used approaches thanks to their easy data interpretation, measure affordability, and real-time in situ analysis. In fluorescent sensors, Si NWs are employed as substrate and coupled with several fluorophores, NWs can be used as quenchers in stem-loop configuration, and have recently been used for direct fluorescent sensing. In this review, an overview on fluorescent sensors based on Si NWs is presented, analyzing the literature of the field and highlighting the advantages and drawbacks for each strategy.

Comparing the morphologies and adsorption behavior of electrospun polystyrene composite fibers with 0D fullerenes, 1D multiwalled carbon nanotubes and 2D graphene oxides

Nanoscale adsorbents with unique engineered morphologies give them properties that can be transformative for water treatment. Unlike bulk-scale and top-down sorbents such as activated carbon, bottom-up nanoscale adsorbents dispersed into water are difficult to recover from water unless enmeshed in macro-scale architectures. Electrospinning is a facile and scalable method of immobilizing nanomaterials (NM) including fullerenes (C60), multi-walled carbon nanotubes (MWCNT) and graphene oxide (GO) into non-woven, flexible polymeric fabric architectures. In this study, electrospinning was used to compare three types of NM-polystyrene (PS) composites. The integration of NMs into electrospun fibers created pores, increased fiber diameter, decreased polymer beading and maintained fibers’ surface pore size distribution for all composites. The scanning electron microscopy inspection indicated that GO in electrospun PS coated the surface of the fibers. This was attributed to the 2D sheet like structure of GO that was pushed outside by the evaporating organic solvent during electrospinning. Phenanthrene adsorption experiments indicated that GO preserved adsorptive properties when incorporated into PS whereas MWCNT and C60 did not. The restricted adsorption of MWCNT and C60 was caused by the concealing of NMs within the PS filaments. On the other hand, partial exposure of GO surfaces enabled adsorption of phenanthrene by GO. Despite the similarities in pore formation and increased diameter when NMs are incorporated into electrospun PS, the type, and morphological properties of the NMs played a critical role on their application potential as an adsorbent for water treatment. Further advances in fiber synthesis are needed such as higher NM loadings in fibers, partial exposure without compromising the composite integrity and continuous pores that allow pollutant access to NM surfaces where adsorption occurs.

3D printing of free-standing Ti3C2Tx/PEO architecture for electromagnetic interference shielding

Recently, two-dimensional (2D) MXenes have emerged as filler materials for electromagnetic interference (EMI) shielding polymer composites due to their extraordinary electrical conductivity, high surface area, hydrophilic nature, and flexibility. Three-dimensional (3D) Printing with MXenes appears to be a new paradigm for manufacturing EMI shielding structures, where complex and specific 3D architecture is often required. In this study, composite inks incorporating 2D Ti3C2Tx MXenes with highly thixotropic properties were developed for the liquid deposition modeling (LDM) 3D Printing method. The use of these inks enabled the fabrication of semi-transparent EMI shielding 3D architectures. The 3D-Printed EMI shields exhibited excellent EMI shielding effectiveness (EMI SE), particularly in the X-band (∼231 dB/mm) and semi-transparency (54.61%) in the visible light range. Moreover, excellent thermal management capability with highly anisotropic thermal conductivity (anisotropic index: 3.6) was achieved through 3D Printing. It is anticipated that the approach developed in this study has potential for the fabrication of advanced EMI shielding architecture with good thermal management capability for various applications, for example, precision wireless communication devices using variable frequencies with multiple channels, autonomous driving vehicles, and the Internet of Things (IoT).

(Invited) The Role of Surface Inhibition in Deterministic Controlled Electrodeposition

Templated electrodeposition is a common practice for the fabrication of metal nanostructures. The nanostructure architecture is set by that of the nanoporous template. For complex nano-architectures such as the metal nanomesh (see Figure) which was developed in our group [1,2], templates will remain necessary. Nonetheless, the 3D nanoporous anodized aluminum oxide (AAO) used for the templated electrodeposition, did form by self-assembly. Regular AAO made from pure Al has only vertical pores with a hexagonal arrangement. The additional horizontal pores in the 3D-AAO are formed with regular interval by doping of the aluminum with Cu [1]. Such level of deterministic control on the growth direction is not yet achievable with electrodeposition. Yet, directed growth of pillars and nanowires has been achieved by control of current inhibiting surface layers, either introduced by additives [3] or intrinsic to the metal electrochemistry [4]. We will shortly discuss the example of indium electrodeposition where InCl intermediate adsorbate is believed to form a coating around electrodeposited indium, leading to large single crystalline morphologies and nanowires when guided by a shallow pattern [3].Conformal deposition of thin-film coatings on high aspect ratio structures is typically claimed by Atomic and Molecular Layer Deposition (ALD and MLD). The nature of the surface limited reactions of these vapor-phase methods allows for the formation of continuous sub-nanometer to a few tens of nanometer thin films with uniform thickness over the most complex architectures. The accuracy of the technique goes at the cost of long deposition cycles especially when very large surface areas with extreme aspect ratios (>100) are involved. In recent years, electrodeposition processes have shown where the metal electrodeposition reaction for e.g. Ni or Pt can be inhibited early on, similarly leading to sub-nanometer to few nanometer thick coatings by cycling [5, 6]. In this paper, we will show examples where this process can be used also to coat nano-architectures such as our nanomesh with very large surface area (100 cm2 per planar cm2) and aspect ratio (100x).Finally, the electrochemical fabrication of oxide thin-films by electro-precipitation and electrochemically induced sol-gel reactions will be discussed. The poor electronic conductivity of oxides makes that the reaction is maintained by ionic conduction through the films, similar as for oxide formation by anodization. The resistive nature of the layers typically allows also for good conformality over high aspect ratio substrates [7]. Similarly, thin polymer films such as poly-phenylene oxide or PPO can be made conformally [8].[1] "The Formation Mechanism of 3D Porous Anodized Aluminum Oxide Templates from an Aluminum Film with Copper Impurities" Johannes Vanpaemel, Alaa Abd-Elnaiem, Stefan De Gendt, Philippe M. Vereecken, J. Phys. Chem. C, 119 (4), 2105–2112 (2015); [2] “Combining High Porosity with High Surface Area in Flexible Interconnected Nanowire Meshes for Hydrogen Generation and Beyond" Stanislaw Zankowski and Philippe M. Vereecken, ACS Appl. Mater. Interfaces, 10 (51), pp 44634–44644 (2018); [3] “Electrodeposited free-standing single-crystal indium nanowires" G. Hautier, J. D’Haen, K. Maex and P.M. Vereecken, ESL 11, K49 (2008); [4] “Fabrication of complex architectures using electrodeposition into patterned self-assembled monolayers” N.S.Pesika, A. Radisic, K.J. Stebe, P.C. Searson, Nano Letters. 6, 1023-1026 (2006); [5] Electro-chemical deposition of sub-nanometer Ni films on TiN” Johannes Vanpaemel, Masahito Sugiura ,Daniel Cuypers, Marleen H. van der Veen, Stefan De Gendt, Stefan and Philippe M. Vereecken, Langmuir, 30 (8), 2047–2053 (2014); [6] “Self-Terminating Growth of Platinum Films by Electrochemical Deposition” Yihua Liu, Dincer Gokcen, Dincer Gokcen, Ugo Bertocci, Tom Moffat, Science 338(6112):1327-30 (2012); [7] "Electrodeposition of Adherent Submicron to Micron Thick Manganese Dioxide Films with Optimized Current Collector Interface for 3D Li-Ion Electrodes" Marina Timmermans, Nouha Labyedh, Felix Mattelaer, Stanislaw Zankowski, Stella Deheryan, Christophe Detavernier, and Philippe M. Vereecken, J. Electrochem. Soc. 164 , 14, D954-D963 (2017); [8] “Self-limiting electropolymerisation of ultrathin, pinhole free poly(phenylene oxide) film on Carbon Nanosheets” S. Deheryan, D. J. Cott, R. Muller, M. Heyns and P. M. Vereecken, Carbon, , 88, 42-50, (2015). Figure 1

Interfacial Assembly and Applications of Functional Mesoporous Materials.

Functional mesoporous materials have gained tremendous attention due to their distinctive properties and potential applications. In recent decades, the self-assembly of micelles and framework precursors into mesostructures on the liquid-solid, liquid-liquid, and gas-liquid interface has been explored in the construction of functional mesoporous materials with diverse compositions, morphologies, mesostructures, and pore sizes. Compared with the one-phase solution synthetic approach, the introduction of a two-phase interface in the synthetic system changes self-assembly behaviors between micelles and framework species, leading to the possibility for the on-demand fabrication of unique mesoporous architectures. In addition, controlling the interfacial tension is critical to manipulate the self-assembly process for precise synthesis. In particular, recent breakthroughs based on the concept of the "monomicelles" assembly mechanism are very promising and interesting for the synthesis of functional mesoporous materials with the precise control. In this review, we highlight the synthetic strategies, principles, and interface engineering at the macroscale, microscale, and nanoscale for oriented interfacial assembly of functional mesoporous materials over the past 10 years. The potential applications in various fields, including adsorption, separation, sensors, catalysis, energy storage, solar cells, and biomedicine, are discussed. Finally, we also propose the remaining challenges, possible directions, and opportunities in this field for the future outlook.

Covalent Immobilisation of a Nanoporous Platinum Film onto a Gold Screen-Printed Electrode for Highly Stable and Selective Non-Enzymatic Glucose Sensing

Progress in the development of commercially available non-enzymatic glucose sensors continues to be problematic due to issues regarding selectivity, reproducibility and stability. Overcoming these issues is a research challenge of significant importance. This study reports a novel fabrication process using a double-layer self-assembly of (3 mercaptopropyl)trimethoxysilane (MPTS) on a gold substrate and co-deposition of a platinum–copper alloy. The subsequent electrochemical dealloying of the less noble copper resulted in a nanoporous platinum structure on the uppermost exposed thiol groups. Amperometric responses at 0.4 V vs. Ag/AgCl found the modification to be highly selective towards glucose in the presence of known interferants. The sensor propagated a rapid response time &lt;5 s and exhibited a wide linear range from 1 mM to 18 mM. Additionally, extremely robust stability was attributed to enhanced attachment due to the strong chemisorption between the gold substrate and the exposed thiol of MPTS. Incorporation of metallic nanomaterials using the self-assembly approach was demonstrated to provide a more reproducible and controlled molecular architecture for sensor fabrication. The successful application of the sensor in real blood serum samples displayed a strong correlation with clinically obtained glucose levels.

Micro 3D Printing by Two-Photon Polymerization: Configurations and Parameters for the Nanoscribe System

3D printing by two-photon polymerization enables the fabrication of microstructures with complex shapes and critical dimensions of a few hundreds of nanometers. On state-of-the art commercial two-photon polymerization systems, an immense 3D design freedom can be put into practice by direct laser writing using a precise fabrication technology, which makes this approach highly attractive for different applications on the microscale, such as microrobotics, micro-optics, or biosensing. However, navigating the different possible configurations and selecting the optimal parameters for the fabrication process often requires intensive testing and optimization. In addition to the more established acrylate-based resins, there is a growing interest in the use of soft materials. In this paper, we demonstrate the fabrication of various microscale structures by two-photon polymerization using a Nanoscribe Photonic Professional GT+ commercial system. Furthermore, we describe the different configurations of the system and parameter selection, as well as commercial resins and their chemical and mechanical properties. Finally, we provide a short guide aiming to serve as starting point for the two-photon polymerization-based fabrication of various microscale architectures with distinct characteristics.

Mapping the Progress in Flexible Electrodes for Wearable Electronic Textiles: Materials, Durability, and Applications

AbstractWith the advancement of nanotechnology and electroactive materials, conventional textiles have transformed into a versatile wearable electronic platform that will inevitably escalate the development of next‐generation flexible electronics. Integration of nanoscale conductive particles such as polymers, metals, or nanocarbons into different structural textile design has simplified the way of personal interactive communications and portable sensing by distributing superior stretchability and functionality in a smart textile device. However, for the real‐life application, it is crucial to recognize the functional reliability of wearable textile electronics. This review comprehensively summarizes the recent progress in electronic textiles (e‐textiles) using different electroactive materials and textile architectures for numerous wearable applications. The first section highlights different textile architectures used in e‐textiles and their various properties. Various electroactive polymers from carbon, metal, and conductive polymers, including their electromechanical properties and wash durability, are then discussed. Subsequently, progress in textile‐based energy harvesting and storage, personal thermal management, flexible sensing, electrocardiography (ECG), electromagnetic interference shielding are presented. Finally, the remaining challenges regarding the current materials and processing strategies are pointed out, and practical strategies to fully realize e‐textile systems are suggested.

Smart Textile for Building and Living

Abstract In construction, textiles can be used either for reinforcing the structure or for finishing design. When we talk about function, the interior is no less important than the exterior and architecture of the building. Thus using textiles to reinforce the structure of buildings, textiles often perform a desired function of reinforcing the “finish.” Building textile materials include fibers that are mixed with concrete, fiberglass reinforcement meshes, insulators, etc. Textile architecture covers permanent tensile structures based on polyester or glass fiber fabrics, with polyvinyl chloride (PVC) or polytetrafluoroethylene (PTFE) coating and awnings generally supported by polyester or polyolefin fabrics, with or without coating, especially for gardening. All above topics are covered within this perspective with the experts from the group of smart textiles for building and living within COST Action CA17107 European Network to Connect Research and Innovation Efforts on Advanced Smart Textiles (CONTEXT) [1].

Hierarchical Microphase Behaviors of Chiral Block Copolymers under Kinetic and Thermodynamic Control

Hierarchical Microphase Behaviors of Chiral Block Copolymers under Kinetic and Thermodynamic Control

Reconstructive spectrometer using a photonic crystal cavity.

Optical spectrometers have propelled scientific and technological advancements in a wide range of fields. While sophisticated systems with excellent performance metrics are serving well in controlled laboratory environments, many applications require systems that are portable, economical, and robust to optical misalignment. Here, we propose and demonstrate a spectrometer that uses a planar one-dimensional photonic crystal cavity as a dispersive element and a reconstructive computational algorithm to extract spectral information from spatial patterns. The simple fabrication and planar architecture of the photonic crystal cavity render our spectrometry platform economical and robust to optical misalignment. The reconstructive algorithm allows miniaturization and portability. The intensity transmitted by the photonic crystal cavity has a wavelength-dependent spatial profile. We generate the spatial transmittance function of the system using finite-difference time-domain method and also estimate the dispersion relation. The transmittance function serves as a transfer function in our reconstructive algorithm. We show accurate estimation of various kinds of input spectra. We also show that the spectral resolution of the system depends on the cavity linewidth that can be improved by increasing the number of periodic layers in distributed Bragg mirrors. Finally, we experimentally estimate the center wavelength and linewidth of the spectrum of an unknown light emitting diode. The estimated values are in good agreement with the values measured using a commercial spectrometer.

An Ultrastable Virus-Like Particle with a Carbon Dot Core and Expanded Sequence Plasticity.

Ordered bio-inorganic hybridization has evolved for the generation of high-performance materials in living organisms and inspires novel strategies to design artificial hybrid materials. Virus-like particles (VLPs) are attracting extensive interest as self-assembling systems and platforms in the fields of biotechnology and nanotechnology. However, as soft nanomaterials, their structural stability remains a general and fundamental problem in various applications. Here, an ultrastable VLP assembled from the major capsid protein (VP1) of simian virus 40 is reported, which contains a carbon dot (C-dot) core. Co-assembly of VP1 with C-dots led to homogeneous T= 1 VLPs with a fourfold increase in VLP yields. The resultant hybrid VLPs showed markedly enhanced structural stability and sequence plasticity. C-dots and a polyhistidine tag fused to the inner-protruding N-terminus of VP1 contributed synergistically to these enhancements, where extensive and strong noncovalent interactions on the C-dot/VP1 interfaces are responsible according to cryo-EM 3D reconstruction, molecular simulation, and affinity measurements. C-dot-enhanced ultrastable VLPs can serve as a new platform, enabling the fabrication of new architectures for bioimaging, theranostics, nanovaccines, etc. The hybridization strategy is simple and can easily be extended to other VLPs and protein nanoparticle systems.

Analysis of influence of fabric architecture and radiation characteristics on effective thermal conductivity of carbonized woven thermal protection composites

Resin-based 2.5D angle interlock woven composites are selected as the thermal protection materials used in thermal protection system (TPS) of hypersonic spacecrafts in entry missions in recent years. The accurate prediction of the effective thermal conductivity of these materials in their carbonization state is critical for evaluating their thermal protection performance. Taking both the thermal conduction and the thermal radiation in carbonized 2.5D angle interlock woven composites into consideration, a multi-scale analysis for obtaining the effective thermal conductivity of carbonized ablative woven composite is developed in this study. The multi-scale method is validated by implementing it to predict the effective thermal conductivity of a carbonized plain-woven silica/phenolic composite. Furthermore, the influence of the meso-structure characteristics of fabric architecture (differences in mesoscopic and macroscopic geometric characteristics caused by weave parameters) and the spectral characteristics (extinction coefficients) on the equivalent properties of carbonized woven composites is analyzed. The main results show that thermal radiation plays an important role in determine the effective thermal conductivity of carbonized woven composites, the weave parameters of yarns significantly affect the heat transfer path in these materials, and the equivalent properties considering both thermal conduction and thermal radiation are related to radiation characteristics and fabric architecture. This study can help for the design of thermal protection materials in current TPS.

Nanomaterials-patterned flexible electrodes for wearable health monitoring: a review.

Electrodes fabricated on a flexible substrate are a revolutionary development in wearable health monitoring due to their lightweight, breathability, comfort, and flexibility to conform to the curvilinear body shape. Different metallic thin-film and plastic-based substrates lack comfort for long-term monitoring applications. However, the insulating nature of different polymer, fiber, and textile substrates requires the deposition of conductive materials to render interactive functionality to substrates. Besides, the high porosity and flexibility of fiber and textile substrates pose a great challenge for the homogenous deposition of active materials. Printing is an excellent process to produce a flexible conductive textile electrode for wearable health monitoring applications due to its low cost and scalability. This article critically reviews the current state of the art of different textile architectures as a substrate for the deposition of conductive nanomaterials. Furthermore, recent progress in various printing processes of nanomaterials, challenges of printing nanomaterials on textiles, and their health monitoring applications are described systematically.Graphical

Roll-to-plate additive manufacturing.

In this paper, we propose a roll-to-plate (R2P) projection micro-stereolithography (PSL) 3D printer, where layers of photopolymer are transferred and photopolymerized through a flexible membrane. Benefitting from the "coat-expose-peel" procedure, highly viscous material can be printed quickly with good vertical resolution. Most importantly, the multinozzle dispensing method enables the fabrication of multimaterial architectures with high throughput, low material consumption, and low cross-contamination. R2P-PSL exhibits superior features for flexible 3D printing in terms of material complexity. For this purpose, we envision infinite scenarios involving potential applications in bionics, biotechnology, microcircuit graphics, photonic devices, microfluidics and material science.

“Environmental phosphorylation” boosting photocatalytic CO2 reduction over polymeric carbon nitride grown on carbon paper at air-liquid-solid joint interfaces

The limited CO2 content in aqueous solution and low adsorption amount of CO2 on catalyst surface lead to poor photocatalytic CO2 reduction activity and selectivity. Herein, the design and fabrication of a novel photocatalytic architecture is reported, accomplished via chemical vapor deposition of polymeric carbon nitride on carbon paper. The as-obtained samples with a hydrophobic surface exhibit excellent CO2 transport and adsorption ability, as well as the building of triphase air-liquid-solid (CO2-H2O-catalyst) joint interfaces, eventually resulting in the inhibition of H2 evolution and great promotion of CO2 reduction with a selectivity of 78.6%. The addition of phosphate to reaction environment makes further improvement of CO2 photoreduction into carbon fuels with a selectivity of 93.8% and an apparent quantum yield of 0.4%. This work provides new insight for constructing efficient photocatalytic architecture of CO2 photoreduction in aqueous solution and demonstrates that phosphate could play a key role in this process.