Functional Composite Materials最新文献

{"title":"Impact of solar radiation on chemical structure and micromechanical properties of cellulose-based humidity-sensing material Cottonid","authors":"R. Scholz,&nbsp;M. Langhansl,&nbsp;M. Hemmerich,&nbsp;J. Meyer,&nbsp;C. Zollfrank,&nbsp;F. Walther","doi":"10.1186/s42252-021-00022-4","DOIUrl":"https://doi.org/10.1186/s42252-021-00022-4","url":null,"abstract":"<p>Renewable and environmentally responsive materials are an energy- and resource-efficient approach in terms of civil engineering applications, e.g. as so-called smart building skins. To evaluate the influence of different environmental stimuli, like humidity or solar radiation, on the long-term actuation behavior and mechanical robustness of these materials, it is necessary to precisely characterize the magnitude and range of stimuli that trigger reactions and the resulting kinetics of a material, respectively, with suitable testing equipment and techniques. The overall aim is to correlate actuation potential and mechanical properties with process- or application-oriented parameters in terms of demand-oriented stimuli-responsive element production. In this study, the impact of solar radiation as environmental trigger on the cellulose-based humidity-sensing material Cottonid, which is a promising candidate for adaptive and autonomously moving elements, was investigated. For simulating solar radiation in the lab, specimens were exposed to short-wavelength blue light as well as a standardized artificial solar irradiation (CIE Solar ID65) in long-term aging experiments. Photodegradation behavior was analyzed by Fourier-transform infrared as well as electron paramagnetic resonance spectroscopy measurements to assess changes in Cottonid’s chemical composition. Subsequently, changes in micromechanical properties on the respective specimens’ surface were investigated with roughness measurements and ultra-micro-hardness tests to characterize variations in stiffness distribution in comparison to the initial condition. Also, thermal effects during long-term aging were considered and contrasted to pure radiative effects. In addition, to investigate the influence of process-related parameters on Cottonid’s humidity-driven deformation behavior, actuation tests were performed in an alternating climate chamber using a customized specimen holder, instrumented with digital image correlation (DIC). DIC was used for precise actuation strain measurements to comparatively evaluate different influences on the material’s sorption behavior. The infrared absorbance spectra of different aging states of irradiated Cottonid indicate oxidative stress on the surface compared to unaged samples. These findings differ under pure thermal loads. EPR spectra could corroborate these findings as radicals were detected, which were attributed to oxidation processes. Instrumented actuation experiments revealed the influence of processing-related parameters on the sorption behavior of the tested and structurally optimized Cottonid variant. Experimental data supports the definition of an optimal process window for stimuli-responsive element production. Based on these results, tailor-made functional materials shall be generated in the future where stimuli-responsiveness can be adjusted through the manufacturing process.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-021-00022-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4237009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3D printing of graphene-based polymeric nanocomposites for biomedical applications","authors":"Magda Silva,&nbsp;Isabel S. Pinho,&nbsp;José A. Covas,&nbsp;Natália M. Alves,&nbsp;Maria C. Paiva","doi":"10.1186/s42252-021-00020-6","DOIUrl":"https://doi.org/10.1186/s42252-021-00020-6","url":null,"abstract":"<p>Additive manufacturing techniques established a new paradigm in the manufacture of composite materials providing a simple solution to build complex, custom designed shapes. In the biomedical field, 3D printing enabled the production of scaffolds with patient-specific requirements, controlling product architecture and microstructure, and have been proposed to regenerate a variety of tissues such as bone, cartilage, or the nervous system. Polymers reinforced with graphene or graphene derivatives have demonstrated potential interest for applications that require electrical and mechanical properties as well as enhanced cell response, presenting increasing interest for applications in the biomedical field. The present review focuses on graphene-based polymer nanocomposites developed for additive manufacturing fabrication, provides an overview of the manufacturing techniques available to reach the different biomedical applications, and summarizes relevant results obtained with 3D printed graphene/polymer scaffolds and biosensors.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-021-00020-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4000133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The impact of molded pulp product process on the mechanical properties of molded Bleached Chemi-Thermo-Mechanical Pulp","authors":"Claire Dislaire,&nbsp;Yves Grohens,&nbsp;Bastien Seantier,&nbsp;Marion Muzy","doi":"10.1186/s42252-021-00023-3","DOIUrl":"https://doi.org/10.1186/s42252-021-00023-3","url":null,"abstract":"<p>This study was carried out using bleached softwood Chemi-Thermo-Mechanical Pulp to evaluate the influence of Molded Pulp Products’ manufacturing process parameters on the finished products’ mechanical and hygroscopic properties. A Taguchi table was done to make 8 tests with specific process parameters such as moulds temperature, pulping time, drying time, and pressing time. The results of these tests were used to obtain an optimized manufacturing process with improved mechanical properties and a lower water uptake after sorption analysis and water immersion. The optimized process parameters allowed us to improve the Young’ Modulus after 30h immersion of 58% and a water uptake reduction of 78% with the first 8 tests done.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-021-00023-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5178126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasonic welding of magnetic hybrid material systems –316L stainless steel to Ni/Cu/Ni-coated Nd2Fe14B magnets","authors":"Moritz Liesegang,&nbsp;Tilmann Beck","doi":"10.1186/s42252-021-00017-1","DOIUrl":"https://doi.org/10.1186/s42252-021-00017-1","url":null,"abstract":"<p>The performance of electric sensors is continuously improving due to the demands of modern vehicles and electronic devices. Magnetic sensors are used in a wide field of applications. However, handling and mounting the typical high-performance rare earth permanent magnets are challenging due to their brittleness. A constant magnetic flux is a key property of the magnetic setup in many devices. State-of-the-art adhesive bonding of magnets in devices can cause problems due to the low durability and viscous behaviour of adhesive polymers, as the magnet may change its position and hence, the magnetic flux distribution in the magnetic setup changes.</p><p>Ultrasonic welding is a powerful technique to join hybrid material systems quickly and reliably, providing high joint strength, even for brittle materials such as glasses, ceramics and rare earth permanent magnets. The latter is being investigated in this work for the first time. The ultrasonic welding process was adapted to join 316L stainless steel, representing potential components of magnetic devices, to Ni/Cu/Ni-coated Nd₂Fe₁₄B. In addition to directly joined steel/magnet-hybrids, ductile aluminium and nickel interlayers were used in order to enhance the joint strength.</p><p>Process parameters were developed and evaluated considering the resulting shear strength of the joints. The highest shear strength of 35?MPa was achieved for 316L/Nd₂Fe₁₄B and 316L/Al/Nd₂Fe₁₄B, which is more than twice the shear strength of adhesively bonded joints of up to 20?MPa, according to the literature. The functional performance of the hybrid material systems, evaluated by the magnetic flux density of the hybrid material systems was the highest for directly bonded joints, and those with a nickel interlayer, which did not show any losses in comparison to the single magnet in its initial state. Joints with an aluminium interlayer showed losses of 3% and adhesively bonded joints showed losses of 7% of the magnetic flux density.</p><p>In summary, the results of this work indicate that ultrasonic welding is a suitable technique to improve the production process and performance of magnetic devices.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-021-00017-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4864051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-material braids for multifunctional laminates: conductive through-thickness reinforcement","authors":"Caroline O’Keeffe,&nbsp;Laura Rhian Pickard,&nbsp;Juan Cao,&nbsp;Giuliano Allegri,&nbsp;Ivana K. Partridge,&nbsp;Dmitry S. Ivanov","doi":"10.1186/s42252-021-00018-0","DOIUrl":"https://doi.org/10.1186/s42252-021-00018-0","url":null,"abstract":"<p>Conventional carbon fibre laminates are known to be moderately electrically conductive in-plane, but have a poor through-thickness conductivity. This poses a problem for functionality aspects that are of increasing importance to industry, such as sensing, current collection, inductive/resistive heating, electromagnetic interference (EMI) shielding, etc. This restriction is of course more pronounced for non-conductive composite reinforcements such as glass, organic or natural fibres. Among various solutions to boost through-thickness electrical conductivity, tufting with hybrid micro-braided metal-carbon fibre yarns is one of the most promising. As a well-characterised method of through thickness reinforcement, tufting is easily implementable in a manufacturing environment. The hybridisation of materials in the braid promotes the resilience and integrity of yarns, while integrating metal wires opens up a wide range of multifunctional applications. Many configurations can be produced by varying braid patterns and the constituting yarns/wires. A predictive design tool is therefore necessary to select the right material configuration for the desired functional and structural performance. This paper suggests a fast and robust method for generating finite-element models of the braids, validates the prediction of micro-architecture and electrical conductivity, and demonstrates successful manufacturing of composites enhanced with braided tufts.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-021-00018-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4677087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of 3D-printed hygromorphs based on different cellulosic fillers","authors":"Matthias Langhansl,&nbsp;Jörg Dörrstein,&nbsp;Peter Hornberger,&nbsp;Cordt Zollfrank","doi":"10.1186/s42252-020-00014-w","DOIUrl":"https://doi.org/10.1186/s42252-020-00014-w","url":null,"abstract":"<p>The aim of this work is to characterize the moisture-dependent actuation behavior of bioinspired and additively manufactured hygromorphs based by following deductive and inductive design approaches. Fused Filament Fabrication (FFF) is employed to print bilayered structures consisting of swellable active layers and rigid passive layers. The active layer is composed of a polylactic acid (PLA) matrix filled with different hygroscopic cellulosic materials (native and modified) up to a filler content of 50?m%. Acrylonitrile Butadiene Styrene (ABS) is used for the passive layer. The FFF process allows the generation of desired differential swelling properties in the composites upon moisture absorption. The moisture dependent actuation strain of the printed bilayers was determined by video analyses. Some influencing geometrical factors which contribute to the actuation were deduced from x-ray diffraction (XRD) and micro computed tomography (μCT). The investigation of the mean cellulose microfibril orientation on the surface of the active layer suggested a preferential orientation with respect to printing direction. Furthermore, a gradient of cellulosic material within a single printed layer was observed, which indicates fiber sedimentation. Comparison with the thermomechanical model derived from Timoshenko (1925) shows that the computational prediction of the moisture dependent actuation is considerably accurate for most selected cellulosic materials and filler contents.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-020-00014-w","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5112382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of tungsten disulfide nanotubes on crystallization of polylactide under uniaxial deformation and annealing","authors":"Fausta Loffredo,&nbsp;Loredana Tammaro,&nbsp;Tiziana Di Luccio,&nbsp;Carmela Borriello,&nbsp;Fulvia Villani,&nbsp;Saverio De Vito,&nbsp;Karthik Ramachandran,&nbsp;Julia A. Kornfield","doi":"10.1186/s42252-021-00016-2","DOIUrl":"https://doi.org/10.1186/s42252-021-00016-2","url":null,"abstract":"<p>Tungsten disulfide (WS₂) nanotubes (NTs) are examined here as a filler for polylactide (PLA) for their ability to accelerate PLA crystallization and for their promising biocompatibility in relevant to biomedical applications of PLA-WS₂ nanocomposites. In this work, we have studied the structural and thermal properties of PLA-WS₂ nanocomposite films varying the concentration of WS₂ NTs from 0 (neat PLA) to 0.6?wt%. The films were uniaxially drawn at 90?°C and annealed at the same temperature for 3 and 10?min. Using wide angle x-ray scattering, Raman spectroscopy and differential scanning calorimetry, we probed the effects of WS₂ NT addition on the structure of the PLA films at various stages of processing (unstretched, stretching, annealing). We found that 0.6?wt% of WS₂ induces the same level of crystallinity in as stretched PLA-WS₂ as annealing in neat PLA for 10?min. These data provide useful insights into the role of WS₂ NTs on the structural evolution of PLA-WS₂ composites under uniaxial deformation, and extend their applicability to situations where fine tuning of PLA crystallinity is desirable.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-021-00016-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5004495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Capacitance measurements on integrated conductors for detection of matrix cracks in GFRP","authors":"Christina Buggisch,&nbsp;Abedin Gagani,&nbsp;Bodo Fiedler","doi":"10.1186/s42252-020-00013-x","DOIUrl":"https://doi.org/10.1186/s42252-020-00013-x","url":null,"abstract":"<p>For the reliable and cost-efficient application of glass fibre polymer composites in structural applications, knowledge of the damage state of the material during operation is necessary. Within this work, a structural health monitoring method based on in-situ electrical capacitance measurements is presented, which enables damage monitoring in glass fibre reinforced polymers. For this purpose, individual glass fibre rovings in a non-crimp fabric were replaced by carbon fibre rovings at regular intervals. Additionally, specimens with solid or stranded copper conductors were manufactured to gain insights into the influences of conductor material and composition. The modified fabrics were implemented as 90^° layers of [0/90₄]_<i>s</i> glass fibre polymer cross-ply laminates. To monitor the progressive damage, conductive rovings were contacted, forming the capacitor walls of interleaved capacitors. Carbon fibre conductors show higher sensitivity of the capacitance to crack formation than solid or stranded copper conductors. Capacitance decrease measured in-situ during tensile tests on specimens with carbon fibre conductors shows a high correlation with crack initiation, further crack formation and speed of crack evolution. An analytical model can describe the correlation based on the assumptions of an ideal plate capacitor. Thus, the structural health monitoring method developed in this work can reveal in-situ knowledge of the material damage state.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4492339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A graphene film interlayer for enhanced electrical conductivity in a carbon-fibre/PEEK composite","authors":"Christopher Leow,&nbsp;Peter B. Kreider,&nbsp;Christian Notthoff,&nbsp;Patrick Kluth,&nbsp;Antonio Tricoli,&nbsp;Paul Compston","doi":"10.1186/s42252-020-00015-9","DOIUrl":"https://doi.org/10.1186/s42252-020-00015-9","url":null,"abstract":"<p>Carbon-fibre reinforced composites are seeing increased deployment, especially in the aerospace industry, and the next-generation of these materials will need to meet demanding performance requirements beyond just specific strength. The incorporation of nanomaterials such as graphene into composites has great potential for enhancing electrical, thermal, and mechanical properties, which could then enable new capabilities such as built-in lightning strike protection and electromagnetic shielding. One major challenge is successful integration of nanomaterials into the composite during the manufacturing process especially for thermoplastic based composites. This work explores the spray deposition of exfoliated graphene in liquid suspensions for the nano-enhancement of electrical properties in carbon-fibre reinforced polyether ether keytone (PEEK) composites. Developed thin films were smooth with RMS roughness of 1.06?μm on Si substrates and RMS roughness of 1.27?μm on CF-PEEK tapes. The addition of 1.3?wt% graphene into the interlayers of CF-PEEK composites resulted in bulk electrical conductivity enhancement both in plane and through thickness of ~?1100% and 67.5% respectively. This approach allows for pre-consolidation introduction of high-performance nanomaterials directly to thermoplastic prepregs which could open simple pathways for the in-situ manufacturing of carbon-fibre reinforced polymer nanocomposites.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-020-00015-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4655921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heparinized chitosan/hydroxyapatite scaffolds stimulate angiogenesis","authors":"Griselda V. Nájera-Romero,&nbsp;Muhammad Yar,&nbsp;Ihtesham Ur Rehman","doi":"10.1186/s42252-020-00012-y","DOIUrl":"https://doi.org/10.1186/s42252-020-00012-y","url":null,"abstract":"<p>Formation of blood vessels during bone regeneration represents a major challenge for tissue engineered constructs. Poor revascularization can lead to scaffold failure and consequently, leads to non-healing fracture. Heparin is known to bind with angiogenic growth factors influencing the process of new blood vessels formation. There are several problems associated with the use of growth factors in clinic such as low stability, uncontrolled delivery to the site, and high price. The aim of the present study was to explore the potential of heparin to produce pro-angiogenic bone regeneration materials. Chitosan/hydroxyapatite freeze-gelled scaffolds were prepared and loaded with heparin. Different concentrations of heparin were successfully loaded onto the scaffolds, its release from the scaffold was analysed by toluidine blue assay and their angiogenic effect was evaluated by chorioallantoic membrane (CAM) assay to determine the optimal concentration of heparin to induce a proangiogenic effect. It was noted that low heparin concentrations exhibited a positive effect, with approximately 28?μg per scaffold indicating a significant increment in blood vessels. The synthesized materials showed no cytotoxic effects when evaluated by using U2OS cell line.</p>","PeriodicalId":576,"journal":{"name":"Functional Composite Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1186/s42252-020-00012-y","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5185592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}