Acrylonitrile Butadiene Styrene Research Articles

3D printing parametric optimization using the power of Taguchi design: an expository paradigm

ABSTRACT The main scope of this work is to exposit good practices of incorporating the power of experimental design in stochastic problems. The filament material extrusion (f-ME) 3D printing process and the acrylonitrile butadiene styrene (ABS) filament were adopted for this scope owing to many processing parameters affecting 3D printed parts quality performance and specifically on flexural strength. Therefore, infill density, raster orientation, printing speed, layer thickness, and nozzle and bed temperatures are optimized using Taguchi orthogonal array and general linear analysis of variances (ANOVA). Linear ANOVA analysis was explained in detail for the first and second runs separately, and all experiment runs, and the residuals were examined for their normality distribution. The contribution of the factors turned out to be similar in each case, showing that the one-run Taguchi design can be safely used at half the cost and time compared to the two-repetition case.

Rapid qualification of fused filament fabrication thermoplastics for cryogenic applications

Thermoplastic additive manufacturing (AM) is an attractive process for fabricating cryogenic componentry, due to the potential for rapid, on-site parts replacement. However, using a process intended for low-feature prototypes in such a demanding application creates survivability concerns. AM further introduces significant material variability that complicates materials qualification. Herein, a highly-repeatable test procedure is developed to qualify as-manufactured samples. Fused Filament Fabrication (FFF) is used to produce both test samples and custom immersion equipment for cryogenic tensile testing, and data quality is improved by modifying the ASTM Type IV geometry. Tensile strength is measured directly, while elastic modulus is calculated using temperature measurements and thermomechanical model fitting. Via this methodology, cryogenic performance is characterized for Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), and Glycol-Modified Polyethylene Terephthalate (PETG). PLA notably demonstrates acceptable strain to failure of 2.6 % and a favorable increase in strength from 47 to 120 MPa when cooled. Testing of carbon fiber filled PLA (CF-PLA) finds a remarkable 250 % increase in strength, from 37 to 130 MPa. Both materials withstand 10 high-stress thermal cycles with mild strength gain, causing a loss of room temperature ductility in neat PLA but not CF-PLA. Dynamic Mechanical Analysis (DMA) indicates a β-transition at −20 to −40 °C, which correlates with the observed changes. These findings show AM thermoplastics are promising for use in cryogenic laboratory environments, and could be modified for use in production applications.

Identification and quantification of microplastics in wastewater treatment plants by spectroscopic and microscopic techniques in Johannesburg East, South Africa

Abstract The occurrence of microplastics in water, their chemistry, physical characteristics, and the efficiency of public wastewater treatment work (WWTW) processes in the removal of microplastics are investigated. Samples were collected from the period 2021 December to 2022 September from two WWTWs in Johannesburg East using 24-h autosamplers. The microplastics were imaged using polarised optical microscopy (POM) and the images were processed using image J 1.53 K to determine the particle counts. The total concentration of microplastics at WWTW A was 3,098 MP/L while WWTW B had 3,561 MP/L. The microplastics identified across the seasons were dominated by angular, fibres, fragments, and films. Fourier transforms infrared (FTIR) spectroscopy identified the polymers such as polyethylene, acrylic, polyethylene terephthalate, and polystyrene in WWTW A and B influent while identifying the polymers such as polystyrene, polyacrylamide, polypropylene, polycarbonate, acrylonitrile butadiene styrene, poly(ethyl cyanoacrylate), carboxyl, poly(ethylene terephthalate), polyethylene, poly(methyl methacrylate), and cellulose in the final effluent. Scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDX) identified Cr, Ca, Fe, Al, Na, Mg, Zn, Cl, P, S, and silicon as additives to microplastics with high-intensity peaks of oxygen and carbon. It is recommended to monitor and regulate microplastics in discharged effluents from WWTWs to minimise environmental pollution.

Study of Polymer Matrices Based on Blends of Polyvinyl Chloride and Grafted Copolymers

The development of mixed matrices is a well-established and suitable method for obtaining new polymeric materials. The combination of two different types of polymers allows you to get a new and unique material that has the properties of both polymers. This paper compares polymer matrices based on polyvinyl chloride (PVC) and various graft copolymers in order to select the optimal compositions for further filling. Domestic acrylonitrile butadiene styrene (ABS) and imported acrylonitrile styrene acrylate (ASA) were chosen as graft copolymers. Despite the manufacturability of copolymers, the subsequent extrusion of filled compositions is more appropriate with a PVC/ABS matrix, since power consumption during processing will be reduced. At the same time, the matrix based on a mixture of PVC/ASA polymers has higher strength properties, but PVC/ABS has the best effect as an impact-resistant matrix. Depending on the content of the copolymer, the structure of compositions based on polymer mixtures can be microdispersed or viscous and layered, which will determine the main physical and mechanical properties. In general, both matrices can be used for further filling, but with a copolymer content of less than 50 phr.

Performance optimization of acrylonitrile butadiene styrene/thermoplastic polyurethane composite foams blown with carbon dioxide using Taguchi technique

AbstractIn this study, acrylonitrile butadiene styrene (ABS)/thermoplastic polyurethane (TPU) composite foam blown with CO2 was fabricated. Optimization was done by design of experiment (DOE) on the cellular structure using the Taguchi method. Foaming time (20, 40, and 80 s), saturation pressure (4, 5.5, and 7 MPa), and foaming temperature (80, 90, and 120°C) are the input parameters. The results obtained from the signal‐to‐noise (S/N) analysis showed that the most effective factor on the cell density (CD) was the saturation pressure and its influence rate was 48.05%, and also, the CD improved with the increase in the saturation pressure because the high saturation pressure leads to an enhancement in gas solubility and the rate of cell nucleation. Moreover, the foaming temperature and the foaming time had a noteworthy impact on the void fraction and the cell size (CS), and they should be controlled accurately. The impression rate of the foaming time on the CS was 50.86%, and also, with increase in the temperature and the time of foaming, the void fraction showed an increasing trend. The optimal values for the CD, the CS, and the void fraction were predicted to be 1.18 × 109 cells/cm3, 5.37 μm, and 0.5744%, respectively.

Extended least squares (ELS) and generalized least squares (GLS) for clutter suppression in hyperspectral images: A theoretical description

Hyperspectral imaging (HSI) has been demonstrated to be useful for estimating spatial distributions of different chemical constituents on surfaces and in imaged scenes, as well as for detecting anomalies and known targets that may be present. In target detection, the objective is to find pixels that contain significant signal attributable to a known “target” spectrum. Unfortunately, measured images are often dominated by “non-target” interference signals with unknown spectra that vary image-to-image. To be effective, target detection algorithms must account for the non-target signal, commonly referred to as “clutter.” The utility of HSI for target detection in spatially complex scenarios can be attributed to two aspects associated with the sensing system: 1) The target can dominate the measured signal in a few individual pixels, although it may have only a minor contribution to the overall signal, and 2) HSI measures many pixels relevant for characterizing clutter that can be used in clutter suppression algorithms to account for interferences.Clutter suppression enables the detection of minor signal sources in HSI, resulting in a sensing system uniquely suited to highly variable environmental scenarios. Popular clutter suppression methods such as extended least squares (ELS) and generalized least squares (GLS) can be described as extensions of the classical least squares (CLS) model. The main advantage of these methods is that they are fast and easy to train on an image-to-image basis providing highly sensitive, image-specific target detection systems. However, the optimization of such models affects the sensitivity and selectivity of the detection. In an effort to assist practitioners interested in clutter suppression, this paper presents a detailed description of the theoretical aspects of ELS and GLS methods used for target detection on hyperspectral images. The concepts are demonstrated with practical examples of the detection of an acrylonitrile butadiene styrene (ABS) particle in sand based on a single near infrared hyperspectral image.

Fabrication of Ba0.5Sr0.5TiO3 components combining rapid prototyping with gelcasting using different gelling systems

Barium strontium titanate (BSTO) is a ceramic that finds application as a high-storage capacitor, sensor, detector, transducer and in tuneable microwave devices and as filters. This paper discusses the synthesis of slurries with suspended particles and fabrication of Ba0.5Sr0.5TiO3 components of different shapes and dimensions using environmentally friendly gelling systems like Isobam and methylcellulose, and also the widely used, but toxic, methyl acrylamide system. Suitable moulds made of acrylonitrile butadiene styrene (ABS) and expanded polystyrene (EPS) are fabricated by rapid prototyping and a concentrated slurry of the required ceramic is set in it by gelcasting; the process is referred to as RPGC process. The green body is further processed to obtain a density higher than 98 %. The sintered products are evaluated by measuring density, microstructure and dielectric properties. This work opens up the possibility of adopting the versatile RPGC process with non-toxic organics for applications by industries.

Comparing the biomechanical properties of conventional suture and all-suture anchors using patient-specific and realistic osteoporotic and non-osteoporotic phantom using 3D printing

Conventional suture anchors (CAs) and all-suture anchors (ASAs) are used for rotator cuff repair. Pull-out strength (POS) is an important factor that affects surgical outcomes. While the fixation mechanism differs between the anchor types and relies on the quality, few studies have compared biomechanical properties of anchors based on bone quality. This study aimed to compare the biomechanical properties of anchors using osteoporotic bone (OB) and non-osteoporotic bone (NOB) simulators. Humerus simulators were fabricated using fused deposition modeling of 3D printing and acrylonitrile butadiene styrene adjusting the thickness of cortical bone and density of cancellous bone based on CT images. Cyclic loading from 10 to 50 N, 10 to 100 N, and 10 to 150 N for 10 cycles was clinically determined at each anchor because the supraspinatus generates a force of 67–125 N in daily activities of normal control. After cyclic loading, the anchor was extruded at a load of 5 mm/min. Displacement, POS, and stiffness were measured. In OB simulators, CAs revealed bigger gap displacement than ASAs with cyclic loading of 10–150 N. ASA showed higher values for POS and stiffness. In NOB simulators, ASAs revealed bigger gap displacement than CAs with cyclic loading of 10–150 N. ASA showed higher values for POS and CA showed higher values for stiffness. POS of anchors depends on anchors ‘displacement and bone stiffness. In conclusion, ASA demonstrated better biomechanical performance than CA in terms of stability under cyclic loading and stiffness with similar POS in OB.

Improved mechanical properties of multiwalled carbon nanotube reinforced acrylonitrile butadiene styrene nanocomposites prepared by twin screw extruder

Dispersion of carbon nanotubes in a thermoplastic polymer matrix is a big challenge in the research community. In the present study, multiwalled carbon nanotubes (MWCNTs) were dispersed in acrylonitrile butadiene styrene (ABS) polymer by a twin screw extruder to improve mechanical and thermal properties. The desired ratio of MWCNT in ABS (1, 2, and 3 wt.%) were dispersed through single and double extrusion processes by a twin screw extruder. The test specimens of produced composites and pure ABS materials were prepared by micro-injection molding. The nanocomposites’ mechanical and thermal properties were investigated and compared with pure ABS. It has been found that the tensile strength has increased significantly for single-extruded and double-extruded composites. A comparative study of MWCNTs reinforced ABS nanocomposites and pure ABS was carried out using thermogravimetric analysis, Fourier's transform infrared, X-ray diffraction, and Scanning electron microscopy. It was found that the microhardness has also increased for single- and double-extruded nanocomposites in comparison to pure ABS.

Identification and quantification of polystyrene microplastics in marine sediments facing a river mouth through NMR spectroscopy

Accurate identification and quantification of microplastic pollution in marine sediments are crucial for assessing their ecological impact. In this study, we explored the potential of Nuclear Magnetic Resonance (NMR) spectroscopy as an analytical tool for the analysis of microplastics in complex environmental matrices such as marine sediments. Two common plastic polymers, polystyrene (PS) and acrylonitrile butadiene styrene (ABS), were investigated. The marine sediments facing the Tiber River mouth (Italy) were collected according to a bathymetric gradient. Results demonstrated the successful detection and quantification of PS in all sediment samples (within a range of 12.3–64.6 μg/L), while no ABS significant signals were found. An increment trend with depth was observed in the PS signal, relatable to its physicochemical properties and the Tiber River plume hydrodynamic characteristics. The NMR's non-destructive nature and minimal sample preparation represent a promising avenue for standardizing protocols to assess the microplastic distribution and impact in marine sediments.

Novel disposable and portable 3D-printed electrochemical apparatus for fast and selective screening of 25E-NBOH in forensic samples

The advent of new psychoactive substances (NPS) has caused enormous difficulty for legal control since they are rapidly commercialized, and their chemical structures are routinely altered. In this aspect, derivatives phenethylamines, such as 25E-NBOH, have received great attention in the forensic scenario. Hence, we propose portable and cost-effective (U$ 5.00) 3D-printed devices for the electrochemical screening of 25E-NBOH for the first time. The cell and all electrodes were printed using acrylonitrile butadiene styrene filament (insulating material) and conductive filament (graphite embedded in a polylactic acid matrix), respectively, both by the fused deposition modeling (FDM) 3D printing technique. The electrochemical apparatus enables micro-volume analysis (50–2000 μL), especially important for low sample volumes. A mechanistic route for the electrochemical oxidation of 25E-NBOH is proposed based on cyclic voltammetric data, which showed two oxidation processes around +0.75 V and +1.00 V and a redox pair between +0.2 and −0.2 V (vs. graphite ink pseudo-reference). A fast and sensitive square-wave voltammetry method was developed, which exhibited a linear working range from 0.85 to 5.1 μmoL−1, detection limit of 0.2 μmol L−1, and good intra-electrode precision (n = 10, RSD <5.3 %). Inter-electrode measurements (n = 3, RSD <9.8 %) also attested that the electrode production process is reproducible. Interference tests in the presence of other drugs frequently found in blotting paper indicated high selectivity of the electrochemical method for screening of 25E-NBOH. Screening analysis of blotting paper confirmed the presence of 25E-NBOH in the seized samples. Moreover, a recovery percentage close to 100 % was found for a spiked saliva sample, suggesting the method's usefulness for quantitative purposes aimed at information on recent drug use.

Design And Analysis of a Pipe Inspection Caterpillar Robot Using Different Materials

The development of a pipe inspection robot employing caterpillar locomotion and constructed with PLA and ABS materials entails a comprehensive process. Beginning with the delineation of specific requirements, such as size and inspection capabilities, the conceptual design is conceived, outlining the robot's features. The subsequent phase involves meticulous 3D modelling using software like SolidWorks, followed by ANSYS analysis to simulate and optimize the robot's structural integrity, stress distribution, and overall performance. PLA and ABS are chosen as 3D printing materials, with PLA offering ease of printing and biodegradability, while ABS contributes durability and temperature resistance. The prototype is then constructed, incorporating motors, sensors, and the caterpillar locomotion system. ANSYS analysis is employed to assess the robot's behaviour under varying conditions, ensuring robustness and reliability. The iterative process of testing and refining the design leads to the optimization of the robot's performance. The final steps involve thorough documentation, regulatory compliance checks, and potential scalability for diverse applications, culminating in the deployment of the caterpillar robot for effective pipe inspection tasks.&#x0D; This paper delves into the design and static structural analysis of a caterpillar robot model utilizing ANSYS, with a specific emphasis on assessing two distinct materials: Acrylonitrile Butadiene Styrene (ABS) and Polylactic acid (PLA). The study involves a comprehensive comparison of various parameters between the two materials, aiming to provide insights into their respective performance and suitability for the caterpillar robot's structural components.

Improved acrylonitrile-butadiene-styrene surface properties via electroless (NiP-SiC) nanocomposite coating

By using electroless nickel-phosphor plating techniques, several (NiP-SiC) nanocomposite coatings were applied to acrylonitrile-butadiene-styrene (ABS) substrates at different temperatures and deposition times. Field emission scanning electron microscope (FESEM) images show that different coating morphologies have been produced. The energy-dispersive x-ray spectroscopy (EDX) data demonstrate that the (NPs) were successfully integrated and nickel and phosphorus are the principal components of the coating. The nickel peaks have been noticed at an angle around (43.29⁰) which belongs to Ni (111) using an X-ray diffraction analysis (XRD) pattern for (NiP-SiC NCCs) produced under different immersion times and temperatures. The nanocomposite coating that was made at 95 °C for 30 min showed the best hydrophobic properties, with a maximum contact angle value of (119.68°), according to the contact angle data. The corrosion behavior was studied via the electrochemical method in (3.5 wt.%) NaCl at (25 °C), and the results showed that the best polarization resistance for the (NiP-SiC) coating is obtained at (90 min at 75 °C) deposition conditions and is (45.14222 kΩ. cm) which produce complete coverage compact coating with growth globular. The best hardness value recorded for a coating that has the most nucleation sites came from a high incorporation nanoparticles level with a small nodule structure which formed at (30 min and 75 °C) and is (3.15 GPa). Finally, the lower wear rate value was collected for the coating having the lower coefficient of friction which was produced at (30 min at 75 °C) deposition conditions and is (0.023 mg/m)).

Acrylonitrile Butadiene Styrene/Thermoplastic Polyurethane Blends for Material Extrusion Three-Dimensional Printing: Effects of Blend Composition on Printability and Properties.

Blend filaments of acrylonitrile butadiene styrene (ABS) and thermoplastic polyurethane (TPU) were prepared at different weight ratios, i.e., 100:0, 70:30, 50:50, 30:70, and 0:100, for FDM printing; the prepared filaments, with an average diameter of 2.77 ± 0.19 mm, were encoded as A100, A70T30, A50T50, A30T70, and T100, respectively. The properties and printability of the filaments were thoroughly investigated. The blend composition, as well as the printing parameters, were optimized to obtain the FDM-printed objects with a well-defined surface structure and minimized warpages. The glass transition temperatures of ABS and TPU in the blends were not much altered from those of the parent filaments, whereas the thermal degradation characteristics of the blend filaments still fell between those of the neat filaments. The fractured surfaces of the filaments, observed by SEM, appeared smoother when higher amounts of TPU integrated; the smoothest surface of the ABS-based filament was found in A30T70, indicating the well-compatible blend characteristic. This was also confirmed by its rheological behavior examined by a parallel plate rheometer at 225 °C. Not only was the printability of the filaments improved, but also the warpages of the 3D-printed specimens were decreased when increasing amount of TPU was incorporated into the filaments. Among the printed objects, the A30T70 specimen exhibited the evenest surface morphology with the lowest surface roughness value of 32.9 ± 13.2 nm and the most uniform and consistent linear printing structure when being fabricated at the nozzle temperature of 225 °C and the printing bed temperature of 60 °C. However, the incorporation of TPU into the filaments markedly cut down both strength and modulus values of the fabricated materials up to about half but assisted the printed articles to absorb more energy, demonstrating that this polymer served as a good and effective toughener for ABS.

Investigation of electrical, electromagnetic interference shielding and tensile properties of 3D-printed acrylonitrile butadiene styrene/carbon nanotube composites

Conductive polymer composites (CPCs) are manufactured by compounding conductive particles with a polymer matrix. There are many applications where they are used, including light-weight applications requiring both electrical and heat conductivity. Carbon nanotubes (CNTs) have been accepted as common materials to accomplish this goal. As part of this research, a material extrusion additive manufacturing (AM) process was utilized to create nanocomposites by a 3D-printing technique. Multi-wall carbon nanotubes (MWCNTs) were mixed in 1, 3 and 6 wt fractions with acrylonitrile butadiene styrene (ABS) and extruded in filament form. Three-dimensionally printed specimens were used to evaluate electrical, electromagnetic interference shielding effectiveness (EMI SE) and tensile properties. The electrical conductivity of the material was 26 times greater than that of ABS. In the X-band of electromagnetic waves, EMI SE's reflected and absorbed portions increased respectively 4 and 16 times. The tensile strength and modulus were enhanced by 15% and 9%, respectively. On composite specimens, microwave heat treatment was applied. There is less void space between the rasters and layers, which helps improve tensile properties. Additionally, 3D-printed specimens were tested for melt flow rate (MFR) and dynamic mechanical behaviour. The nozzle has experienced some wear due to the intrinsic abrasive nature of CNTs.

Unleashing the power of SAN: Innovative in situ fibrillation and moisture-crosslinking techniques yield stronger, tougher, and Greener material than ABS

Styrene-acrylonitrile (SAN) is widely used in various applications due to its excellent properties, including thermal stability, dimensional stability, and chemical resistance. However, poor toughness has limited its applications. In this study, an innovative in-situ fibrillation technique was employed to create nanofibers of thermoplastic polyurethane (TPU) in the SAN matrix. Silane was initially grafted onto TPU, followed by the development of nanofibril TPU, and lastly, post-crosslinking was conducted to retain the nanofibril structure. The grafting reaction was analyzed using Fourier Transform Infrared Spectroscopy (FTIR) and Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR). FTIR and NMR data were used in conjunction with the gel content test to confirm the involved grafting, hydrolysis, and crosslinking reactions. Observations with a Scanning Electron Microscope (SEM) revealed the formation of nanoscale TPU fibers ranging from 90 to 360 nm for various TPU contents. Because of nanofibril TPU's high aspect ratio and the effective SAN-TPU interaction, the required TPU decreased to 1 wt%. Due to the minimal use of rubber, SAN's stiffness was not compromised and compared to pure SAN and a spherical structure with the same concentration, tensile toughness increased by 350% and 200%, respectively. The fracture mechanism was investigated for both the short and long timeframes of deformation, and several potential hypotheses were proposed. Finally, this novel toughened SAN was compared with one of the most effective toughened acrylonitrile butadiene styrene (ABS) materials that contain 40 wt% spherical butadiene rubber (BR) domains.

Development of Screw-Based 3D Printing Machine and Process Experiments for Short Fiber Reinforced Polymer Composites

3D printing is one of the flexible additive manufacturing (AM) processes that can be used to fabricate parts from various types of materials such as polymers, metal, and ceramic. 3D printing process is one of the famous techniques for printing the product from the filament causing material degradation. Granule-based 3D printing or screw-based material extrusion 3D printing is an alternative process that can create the parts from plastic or composite granule raw materials. However, there are limited use and study in the designation of granule-based 3D printing and process parameters including material temperature, heat bed temperature, nozzle size, and printing speed. These process parameters play a significant role in the properties of 3D printing parts. Some parameters cannot be adjusted in the commercial 3D printing process. Thus, the purposes of this study are to develop a screw-based material extrusion 3D printing machine that can freely adjust the process parameters and to investigate the effect of 3D printing parameters on the appearance and mechanical properties of printed parts. Pellets of neat acrylonitrile butadiene styrene (ABS) and short glass fiber/ABS composites are used in the experiments. Six process parameters were studied, including % fiberglass, printing temperature, printing speed, nozzle size, % Infill, and heat bed temperature. Each parameter has 3 levels, which were designed by the Taguchi L18 method. The results were evaluated by the main effect plot method and showed that the printing speed, nozzle size, and %fiberglass are the top 3 parameters that affect tensile strength. The nozzle size, %infill, and %fiberglass are the top 3 parameters that affect Young’s modulus. The granule-based 3D printing machine was completely developed; however, the extruded plastic line from the nozzle was difficult to control resulting in poor product quality. Thus, the feedback control for controlling the screw-extruder speed and temperature will be developed in future work.

Enhancing vibration damping properties of MABS/VDT blends using SEBS-g-MAH as a compatibilizer

This investigation focuses on the enhancement of the damping properties of Methyl Methacrylate Acrylonitrile Butadiene Styrene (MABS) through the formulation of a specific blend with a styrene-based elastomer referred to as VDT, and with the incorporation of Ethylene Butylene Styrene grafted Maleic Anhydride (SEBS-g-MAH) as a compatibilizer. In contrast to traditional investigations that primarily focus on the mechanical rigidity, thermal conductivity, and electrical conductivity of materials, this research explores the enhancement of damping properties via the process of melt compounding. Using a twin-screw extruder in a precise melt-mixing process, a multiphase polymer blend is generated by including three different weight ratios (10, 20, and 30 wt.%) of VDT. Furthermore, in order to enhance the compatibility between MABS and VDT, three different weight percentages of SEBS-g-MAH (2, 4, and 6 wt.%) have been used in the blend. Tensile testing, laser confocal microscopy, dynamic mechanical analysis (DMA) and nuclear magnetic resonance (NMR), are used to thoroughly assess the compatibility and effectiveness of the blends. The results indicate that the damping performance of the blend increases in direct proportion to the amount of VDT. Conversely, the addition of SEBS-g-MAH has a non-monotonic effect: the inclusion of 4 wt.% SEBS-g-MAH leads to the most substantial improvements in both damping performance and tensile strength, exceeding the results obtained with 2 wt.% and 6 wt.% compatibilizer. The study highlights the need for carefully choosing the right wt.% of compatibilizers when aiming to formulate polymer blends with enhanced vibration dampening properties.

Sputtering: An eco‐friendly technique to obtain polymer‐metal hybrids

AbstractAmong the methods commonly used to obtain polymer‐metal hybrids, sputtering has stood out for its ability to deposit thin films at room temperature. Another highlight is that it does not produce toxic gases or residues to the environment, making it an eco‐friendly solution. This work aimed to produce and characterize stainless steel (SS) films on acrylonitrile‐butadiene‐styrene (ABS) polymer using a magnetron sputtering with a direct current source. The ABS‐SS surface and interface, the ABS thermal behavior, and the film‐substrate adhesion quality were analyzed. The characterization techniques were atomic force microscopy and scanning electron microscopy to reveal the surface, x‐ray fluorescence spectroscopy to determine the chemical composition, and transmission electron microscopy to determine the phases on the ABS‐SS interface. The samples' thermal behavior was analyzed through thermogravimetry and differential scanning calorimetry. Method B from the ASTM D3359 standard qualitatively evaluated the film‐substrate adhesion. The characterizations showed that the ABS did not degrade significantly during SS deposition and that the sample had acceptable film‐substrate adhesion quality, making the technique and deposition parameters suitable for the obtention of this hybrid material.

Analysis of Drying Front Propagation and Coupled Heat and Mass Transfer During Evaporation From Additively Manufactured Porous Structures Under a Solar Flux.

Drying front propagation and coupled heat and mass transfer analysis from porous media is critical for soil-water dynamics, electronics cooling, and evaporative drying. In this study, de-ionized water was evaporated from three 3D printed porous structures (with 0.41 mm, 0.41 mm, and 0.16 mm effective radii, respectively) created out of acrylonitrile butadiene styrene (ABS) plastic using stereolithography technology. The structures were immersed in water until all the pores were invaded and then placed on the top of a sensitive scale to record evaporative mass loss. A 1000 W/m2 heat flux was applied with a solar simulator to the top of each structure to accelerate evaporation. The evaporative mass losses were recorded at 15 min time intervals and plotted against time to compare evaporation rates from the three structures. The evaporation phenomena were captured with a high-speed camera from the side of the structures to observe the drying front propagation during evaporation, and a high-resolution thermal camera was used to capture images to visualize the thermal gradients during evaporation. The 3D-structure with the smallest effective pore radius (i.e., 0.16 mm) experienced the sharpest decrease in the mass loss as the water evaporated from 0.8 g to 0.1 g within 180 min. The designed pore structures influenced hydraulic linkages, and therefore, evaporation processes. A coupled heat-and-mass-transfer model modeled constant rate evaporation, and the falling rate period was modeled through the normalized evaporation rate.