Adding nanoparticles (NPs) into surfactant solutions represents a promising strategy for enhancing oil displacement in porous media, with significant implications for various engineering and ...environmental applications, including soil remediation and enhanced oil recovery from underground reservoirs. Recent investigations have focused on the integration of silica and alumina NPs into anionic surfactant solutions to mitigate interfacial tension (IFT) and reduce the contact angle between the surfactant and oil phases. However, the utilization of these injection scenarios in fractured porous media has received limited attention. In this experimental study, we employed a 3D printer to design and fabricate three distinct porous media types: single permeability (S), fractured (F), and dual permeability (D). Subsequently, we prepared the sodium dodecyl sulfate (SDS) solution by adding SDS powder into a brine solution containing 2% NaCl. Nanofluids were then produced through the dispersion of SiO2 and Al2O3 NPs in the SDS solution using a sonicator. The prepared solutions were subsequently injected into each porous medium, while the recovery process was recorded using a camera. Recovery rates for each scenario were calculated utilizing a developed Python image processing code. Furthermore, analysis of the images enabled us to demonstrate the behavior and growth of the displacing phase’s fingers within the oil phase. Findings from this study showed that SDS injection into the S medium resulted in an approximate 60% oil recovery. Adding silica and alumina NPs into the SDS solution led to enhanced total recovery rates of up to 70% and 78%, respectively. The recovery results obtained from tests conducted within the F medium exhibited a pronounced decrease, with the SDS solution sweeping a mere 25% of the medium, while the silica and alumina nanofluids recovered 43% and 47%, of the oil respectively. Notably, the silica nanofluid displayed superior performance to the alumina nanofluid during the breakthrough stage in the F medium. In the D medium, the injection of SDS, silica, and alumina nanofluids achieved total recovery rates of 49%, 53%, and 56%, respectively. These outcomes highlight the diminished effectiveness of nanofluids within the dual permeable medium.
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•Different porous media (single permeability, dual permeability and fractured structure) were fabricated utilizing 3D printing technology. dual permeability (D).•A base solution was prepared by combining NaCl and sodium dodecyl sulfate (SDS), followed by the addition of SiO2 and Al2O3 nanopowders.
Origami has recently emerged as a platform for building functional engineering systems with versatile characteristics that targeted niche applications. One widely utilized origami-based structure is ...known as the Kresling origami spring (KOS), which inspired, among many other things, the design of vibration isolators, fluidic muscles, and mechanical bit memory switches. KOSs are traditionally constructed out of foldable materials (e.g. paper, kapton, fabric, polyethylene terephthalate, and acetate sheets) using conventional fabrication processes which include manual folding and creasing. Such materials and fabrication methods are ideal for conceptual illustrations and laboratory testing, but lack many important aspects necessary for real-world implementation. In addition to the very low durability resulting from the high plastic deformations at the folds; lack of repeatability, and high variation of performance among similar samples are typically inevitable. To circumvent these issues, this paper presents a novel approach for the design and 3D printing of a KOS which mimics the qualitative behavior of a paper-based KOS without compromising on durability, repeatability, and functionality. In the new design, each fundamental triangle in the traditional KOS is replaced by an inner central rigid core and an outer flexible rubber-like frame, which are fabricated out of different visco-elastic materials using advanced 3D printing technologies. The quasi-static behavior of the fabricated springs is assessed under both compressive and tensile loads. It is shown that KOSs with linear, softening, hardening, mono- and bi-stable restoring force behavior can be fabricated using the proposed design by simple changes to the geometric design parameters. The durability of the resulting springs is also assessed with no changes observed in the quasi-static behavior even after 5000 loading cycles.
Conventional manufacturing of aeronautic and aerospace parts requires substantial amount of resources (energy and materials) while generating high quantities of waste and carbon dioxide emissions. ...Metal additive manufacturing (MAM) has the potential to reduce resource consumption, which is particularly important for energy-intensive materials such as titanium. We undertake a systematic literature review of MAM processes for the aerospace/aeronautic sector focusing on energy and material efficiency. Relevant literature was classified and discussed based on the life cycle stages at which resource efficiency strategies for MAM were identified: (1) product design; (2) material development and sourcing; (3) processes development, control, and optimization; (4) end-of-life extension and circular economy. Results highlight the key factors required to optimize MAM and the relevance of assessing its environmental impact compared to conventional manufacturing. Material and energy efficiency vary significantly between different MAM processes due to several factors directly linked to the process but also associated with the supply chain, e.g. electricity mix or material sourcing. Further research could explore new trends in technological development for circularity or multi-material MAM.
•Metal Additive Manufacturing (MAM) as an enabler of resource efficiency in aeronautics.•Efficiency strategies were identified at different levels: design, material, process, and end-of-life.•Key factors affecting MAM overall performance were identified.•Material and energy efficiency vary significantly between different MAM processes.
•Developed novel material for direct 3D printing of ion exchange adsorbers.•3D printed adsorbers showed comparable protein binding capacity to commercial materials.•Designed new adsorber geometry to ...enable continuous protein uptake measurements.•3D printing of complex structures such as the Schoen Gyroid with 500 μm features.
Monolithic adsorbers with anion exchange (AEX) properties have been 3D printed in an easy one-step process, i.e. not requiring post-functionalization to introduce the AEX ligands. The adsorber, 3D printed using a commercial digital light processing (DLP) printer, was obtained by copolymerisation of a bifunctional monomer bearing a positively charged quaternary amine as well as an acrylate group, with the biocompatible crosslinker polyethylene glycol diacrylate (PEGDA). To increase the surface area, polyethylene glycol was introduced into the material formulation as pore forming agent. The influence of photoinitiator (Omnirad 819) and photoabsorber (Reactive Orange 16, RO16) concentration was investigated in order to optimize printing resolution, allowing to reliably 3D print features as small as 200 μm and of highly complex Schoen Gyroids. Protein binding was measured on AEX adsorbers with a range of ligand densities (0.00, 2.03, 2.60 and 3.18 mmol/mL) using bovine serum albumin (BSA) and c-phycocyanin (CPC) as model proteins. The highest equilibrium binding capacity was found for the material presenting the lowest ligand density analysed (2.03 mmol/mL), adsorbing 73.7 ± 5.9 mg/mL and 38.0 ± 2.2 mg/mL of BSA and CPC, respectively. This novel 3D printed material displayed binding capacities in par or even higher than commercially available chromatographic resins. We expect that the herein presented approach of using bifunctional monomers, bearing commonly used chromatography ligands, will help overcome the material limitations currently refraining 3D printing applications in separation sciences.
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•Printability (3D) of beams of two recycled materials was evaluated experimentally.•Flexural (bending) tests showed excellent performance of the composite beams.•Composite beams with ...plastic showed higher loads than beams with timber.•We quantified to what extent and which material can provide flexural strength.•The infill density was found to be effective in bending capacity.
The abundance of the waste materials of wood and plastic inspired the authors to explore the possibility of 3D printing the recycled materials as composite beams. This paper addresses the design, fabrication, and structural testing of 3D printed composite beams under 3-point bending. The authors believe that 3D printing of beams from timber waste and Polylactic Acid (PLA) is a state-of-the-art and has excellent potential to be transformed to state-of-the-practice in the construction industry. Beams with different compositions of materials and printing densities were designed, printed and tested to failure. This paper elaborates details of the design and printing of the beams, which then will be followed by detailed discussions as to how each beam reacts under flexural loading in terms of deformability, stiffness, strength-to-mass ratio, failure, and load-carrying capacity. General deformations of the specimens implied that the design of the specimens was quite successful in avoiding any premature failure. Large deflections of all specimens indicated that the shear strengthening performed effectively as the shear-vulnerable areas were not affected by the shear failure. The infill density affects the flexural capacity, which is obviously due to the amount of material present against loading. The capacity of the specimens with PLA at the top and bottom sections of the beams was higher than the equivalent beams with timber flanges. Overall, very promising results were obtained with a view to extending the idea into more advanced elements and techniques to develop various 3D printed structural elements towards the ongoing discussion on automation in the construction and prefabrication.
Additive manufacturing is based on high-precision material deposition to build a final part or component by using various techniques. It is being one of the main advances in the fourth industrial ...revolution. This type of manufacturing is not new, although it is growing. There are many types of additive manufacturing techniques, and the use of efficient inspection methods to ensure a certain level of quality, and to detect faults, porosities, etc., are required in the industry. Nondestructive Testing is widely applied, and particularly in additive manufacturing, to ensure efficient quality control and preventive/predictive maintenance without changing the characteristics and initial state of the material. Each Nondestructive Testing technique is based on different physical principles; therefore, the selection and correct use of each technique depends on the application, the manufacturing process, the type of material and the possible discontinuities, among many others. This article develops a complete, exhaustive, and updated review and analysis of the state of the art of Nondestructive Testing applied in additive manufacturing. The main characteristics of the processes are analyzed, highlighting the most relevant works and the challenges that each technique should face. An analysis of techniques necessary for the development of Nondestructive Evaluation has been carried out, mainly Machine Learning techniques used for the quantification, detection and analysis of defects detected by Nondestructive Testing techniques.
•An exhaustive and updated review of the state of the art of Nondestructive Testing applied in additive manufacturing.•The main characteristics of the processes are analyzed, showing the most relevant works and challenges for each technique.•An analysis of techniques necessary for the development of Nondestructive Evaluation has been carried out.•Machine Learning techniques are used for the analysis of defects detected by Nondestructive Testing techniques.
Three-dimensional (3D) printing offers the advantages of customisation, reproducibility and rapid production. In parallel, there is a demand for electrochemical components designed for ...miniaturisation or customisation of devices. Herein we report a straightforward, fast and simple method to prepare an Ag/AgCl pseudo-reference electrode primarily based on 3D printing using a graphene/polylactic acid filament. The fabrication process involves electrodeposition of silver followed by bleaching to form AgCl on the surface of the electrode. Scanning electron microscopy and energy dispersive X-ray spectroscopy confirm the fabrication process. Open circuit potential measurements against commercial Ag/AgCl reference electrodes reveal a difference of 14 ± 0.3 mV. Nonetheless, the values are stable and reproducible, fulfilling the necessary requirements of a reference electrode. The performance of the 3D-printed pseudo-reference electrode was tested via cyclic voltammetry in two redox systems, Fe(CN)63−/4− and Ru(NH3)62+/3+. Fabrication of stable 3D-printed reference electrodes represents a key step in the production of fully 3D-printable electrochemical systems.
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•A modified 3D-printed electrode is used as a pseudo-reference electrode.•Its potential is stable and reproducible.•The 3D-printed Ag/AgCl electrode exhibits a small potential difference compared with a classical Ag/AgCl reference electrode.
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•In situ bone repair scaffolds with different content Ti2AlN/polycaprolactone were prepared by FDM 3D printing technology.•Ti2AlN/polycaprolactone scaffolds were used to repair the ...bone defects of rat tibia and rabbit maxillofacial bone.•Scaffold with 5% Ti2AlN content showed the best osteogenesis in vitro and bone repair in vivo.•Transcriptome profile revealed the osteogenic signaling pathway involved in Ti2AlN.
Obtaining a safe and reliable scaffold that can be rapidly fabricated and used for clinical bone defect repair has always been a challenge. In this study, polycaprolactone (PCL) composite scaffolds with various MXene (Ti2AlN) contents were prepared using 3D printing technology. The effects of different contents of Ti2AlN on the mechanical properties, hydrophilicity, cytocompatibility, and osteogenic differentiation ability were systematically studied and analysed. In vitro experiments showed that scaffolds containing 5% Ti2AlN (PCL@5#Ti2AlN) obtained the best cell adhesion and proliferation ability and significantly upregulated the alkaline phosphatase (ALP) level. In vivo experiments of tibial defect repair in rats showed that the PCL scaffold containing 5% Ti2AlN (PCL@5#Ti2AlN) could significantly promote the formation of new bone, and the experimental results of rabbit maxillofacial bone defect repair further proved that the PCL@5#Ti2AlN scaffold could effectively promote the repair of bone defects. Transcriptome analysis indicated that Ti2AlN may promote osteogenic differentiation by the Wnt/β-catenin signaling pathway and calcium-binding proteins. These findings suggest that Ti2AlN/PCL composite scaffolds with improved in situ bone repair ability represent an intelligent strategy for bone defect repair.
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