White paper on the future of plasma science and technology in plastics and textiles

This is the peer reviewed version of the following article: “Uros, C., Walsh, J., Cernák, M., Labay, C., Canal, J.M., Canal, C. (2019) White paper on the future of plasma science and technology in plastics and textiles. Plasma processes and polymers, 16 1 which has been published in final form at [doi: 10.1002/ppap.201700228]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."This white paper considers the future of plasma science and technology related to the manufacturing and modifications of plastics and textiles, summarizing existing efforts and the current state‐of‐art for major topics related to plasma processing techniques. It draws on the frontier of plasma technologies in order to see beyond and identify the grand challenges which we face in the following 5–10 years. To progress and move the frontier forward, the paper highlights the major enabling technologies and topics related to the design of surfaces, coatings and materials with non‐equilibrium plasmas. The aim is to progress the field of plastics and textile production using advanced plasma processing as the key enabling technology which is environmentally friendly, cost efficient, and offers high‐speed processingPeer ReviewedPostprint (author's final draft

Biomineral Amorphous Lasers through Light-Scattering Surfaces Assembled by Electrospun Fiber Templates

New materials aim at exploiting the great control of living organisms over molecular architectures and minerals. Optical biomimetics has been widely developed by microengineering, leading to photonic components with order resembling those found in plants and animals. These systems, however, are realized by complicated and adverse processes. Here we show how biomineralization might enable the one-step generation of components for amorphous photonics, in which light is made to travel through disordered scattering systems, and particularly of active devices such as random lasers, by using electrospun fiber templates. The amount of bio-enzymatically produced silica is related to light-scattering capacity and the resulting organosilica surfaces exhibit a transport mean free path for light as low as 3 micron, and lasing with linewidth below 0.2 nm. The resulting, complex optical material is characterized and modelled to elucidate scattered fields and lasing performance. Tightly-controlled nanofabrication of direct biological inspiration establishes a new concept for the additive manufacturing of engineered light-diffusing materials and photonic components, not addressed by existing technologies.Comment: 37 pages, 11 figure

CHARACTERIZATION AND ENHANCEMENT OF SENSING PROPERTIES OF PIEZOELECTRIC MATERIALS WITH APPLICATIONS TO VIBRATION SUPPRESSION

This thesis undertakes the study of piezoelectric properties of polymer-based fabric and film sensors. An enhancement in piezoelectric properties of such sensors, as noted through earlier work, is observed with increasing weight ratios of nanomaterials dispersed in the polymer matrix. A comprehensive mathematical model using cantilever beams is developed to analyze this enhancement both qualitatively and quantitatively. An experimental setup is also developed to implement the proposed real time signal processing necessary to collect required data towards the characterization. In order to distinguish piezoelectric materials from other materials, study of the frequency response of developed fabric sensors to periodic chirp type actuation signals, is also established. Linear Euler-Bernoulli beam theory is used, to model piezoelectric actuation of cantilever beams. The theory has been extended to integrate piezoelectric sensing with the governing equations of motion to obtain a numerical solution to the governing partial differential equation of motion. All equations are derived using a distributed-parameters model applying the extended Hamilton Principle. Results obtained are compared to base values from literature for known materials. Piezoelectric materials are also known to possess bi-stiffness properties, having a higher modulus of elasticity in their open circuit configuration as compared to that in their short circuit configuration. Through research, it has been observed that the weight ratio of dispersed nanomaterials does not affect the piezoelectric properties alone but also has an effect on the mechanical properties and beyond a threshold, established for every polymer analyzed, the increase in the tensile properties of the fabric developed cannot be ignored. This study is extended to analyze the enhancement in the difference between the two moduli of elasticity for the fabric sensors in their respective configurations. The bi-stiffness elements can be used effectively to suppress vibrations implementing a semi-active vibration damping method known as `Switched Stiffness\u27. This concept is studied in regard to continuous systems, and the underlying principle of switching between two configurations is mathematically modeled. The developed control law for vibration suppression is then integrated using non-contact type measurement of tip deflection to suppress vibrations induced in cantilever beams, using the fabric sensors developed at Clemson University. The damping characteristics have been analyzed to study the enhancement in the difference between the higher and lower stiffness values and qualitative conclusions are drawn. Using the mathematical modeling developed to implement the `Switched Stiffness\u27 concept, a novel method to measure the coupling coefficient, k31, a characteristic constant for piezoelectric materials, is established and validated. The results of this measurement are used to decouple the piezoelectric properties from the mechanical properties and a generalized framework to completely characterize piezoelectric materials towards other constants has been proposed

Gilbert-Taylor cones and multi-phase Electrospinning

In this thesis a numerical method is developed, which allows to compute the shape of electrically charged liquid surfaces of droplets of finite conductivity

Factories of the Future

Engineering; Industrial engineering; Production engineerin

Magnetic nanofibers for remotely triggered catalytic activity applied to the degradation of organic pollutants

This work reports on the fabrication and characterization of a novel type of electrospun magnetic nanofibers (MNFs), and their application as a magnetically-activable catalysts for degradation of organic pollutants. The magnetic stimulation capability for the catalytic action is provided by iron-manganese oxide (MnxFe2-xO4) magnetic nanoparticles (MNPs) embedded into electrospun polyacrylonitrile (PAN), which provides stability and chemical resistance. The MNPs (average size d = 40 ± 7 nm) were first obtained by a green and fast sonochemical route, and subsequently embedded into electrospun PAN nanofibers. The final MNFs showed an average diameter of 760 ± 150 nm, providing a superhydrophobic surface with contact angle (θc = 165°), as well as a considerable amount ( 50 % wt.) of embedded MNPs (Mn0.5Fe2.5O4), thermally stable up to temperatures of 330 °C. The catalytic Fe2+/3+/Mn2+/3+/4+ active centers on the MNPs of MNF’s surface could be remotely activated by alternating magnetic fields (AMF) to degrade the methyl blue (MB). Remarkable stability of the MNFs during heating under extreme pH conditions (3 80 %, after several cycles of reusing the same sample without any regeneration process. The capacity of these materials as a catalytic material with magnetic remote activation makes them appealing for those catalytic applications under conditions of darkness or restrained access, where photocatalytic reaction cannot be achieved

SciTech News Volume 71, No. 1 (2017)

Columns and Reports From the Editor 3 Division News Science-Technology Division 5 Chemistry Division 8 Engineering Division Aerospace Section of the Engineering Division 9 Architecture, Building Engineering, Construction and Design Section of the Engineering Division 11 Reviews Sci-Tech Book News Reviews 12 Advertisements IEEE

Electrospun polymer nanofibers for electromechanical transduction investigated by scanning probe microscopy

Negli ultimi anni, il copolimero ferroelettrico P(VDF-TrFE), ha suscitato un grande interesse nella ricerca scientifica per le potenziali applicazioni elettroniche come ad esempio l’energy harvesting per la produzione di dispositivi indossabili e autoalimentabili, sensori biocompatibili e memorie non volatili. Molti sforzi si sono concentrati nello sviluppo di procedure di fabbricazione che possano migliorare le performance elettromeccaniche di questi materiali. Una delle soluzioni proposte è un processo chiamato elettrofilatura, una tecnica efficiente e a basso costo che sarebbe in grado di realizzare nanofibre polimeriche già polarizzate e pronte per l’integrazione nei dispositivi. Dalle analisi microscopiche svolte in questa tesi, utilizzando tecniche di microscopia a scansione di sonda, è stato scoperto che in realtà l’elettrofilatura non provoca polarizzazione nelle fibre, bensì induce un processo di iniezione di cariche all’interno del materiale che, se testato a livello macroscopico, mostra un’apparente risposta ferroelettrica dovuta però alle cariche intrappolate, come in un elettrete. Nonostante ciò, dopo la dissipazione delle cariche spaziali, ho potuto dimostrare, grazie al’implementazione della Switching Spectroscopy PFM ad alto potenziale, che le nanofibre elettrofilate possono essere polarizzate e mostrano proprietà piezoelettriche simili a quelle del film sottile. Quindi, inducendo la completa polarizzazione del network dopo la deposizione, è auspicabile un miglioramento delle proprietà elettromeccaniche dei dispositivi basati su nano-fibre elettrofilate