DOCSLIB.ORG

(DMA) for Characterizing Interfacial Interactions in Filled Polymers

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
(DMA) for Characterizing Interfacial Interactions in Filled Polymers Review Use of Dynamic Mechanical Analysis (DMA) for Characterizing Interfacial Interactions in Filled Polymers Muhammad Ahsan Bashir Jotun AS, Hystadveien 167, 3209 Sandefjord, Norway; [email protected] Abstract: Dynamic mechanical analysis (DMA) provides reliable information about the viscoelastic behavior of neat and filled polymers. The properties of filled polymers are relevant to different indus- tries as protective organic coatings, composites etc. Interfacial interactions in filled polymers play an important role in determining their bulk properties and performance during service life. In this brief review article, studies that used DMA to characterize the interfacial interactions in filled polymers have been reviewed. The available open literature provides a mixed opinion about the influence of interfacial interactions on the glass transition temperature of filled polymers. Nevertheless, it appears that in the case of strong interfacial interactions between the filler particles and the polymeric matrix, the peak value of tan δ is reduced in comparison to that of a filled polymer where these interactions are weak. Keywords: DMA; glass transition temperature; organic coatings; interfacial interactions; interphase 1. Introduction Interfaces play an important role in determining the bulk properties and performance Citation: Bashir, M.A. Use of during the service life of filled polymers. Filled polymers generally refer to polymers Dynamic Mechanical Analysis (DMA) blended with different particles, which are commonly called fillers. Certain additives are for Characterizing Interfacial also used in filled polymers to improve their properties. Organic coatings are a special case Interactions in Filled Polymers. Solids of filled polymers. As commercial organic coatings are composed of binders, co-binders, 2021, 2, 108–120. https://doi.org/ dispersing agents, defoaming agents, extenders/fillers, pigments, solvents, co-solvents, 10.3390/solids2010006 curing agents etc., the interface(s) between different constituents of an organic coating influences the uniform dispersion of each ingredient, which then translates into good Academic Editor: Joaquim Carneiro film formation and isotropic properties of the final coating. In a broader sense, all other components of a commercial coating are liquid (or get dissolved into the solvent(s)) except Received: 28 December 2020 the extenders/fillers/pigments. After application and curing, the extenders are consid- Accepted: 23 February 2021 Published: 1 March 2021 ered as the dispersed phase, whereas the binder (including cross-linked curing agent, residual solvents, additives such as dispersing agents, defoamers etc.) is considered as Publisher’s Note: MDPI stays neutral the matrix. A variety of extenders are used in the organic coatings commercially e.g., inor- with regard to jurisdictional claims in ganic particles (such as titanium dioxide, silica, talc, feldspar, calcium carbonate, kaolin etc.), published maps and institutional affil- metallic particles (such as zinc, zinc oxide etc.), carbonaceous materials (carbon black, etc.). iations. Nanoparticles (non-functionalized or functionalized) of various materials such as silica, carbon (graphene, graphene oxide, reduced graphene oxide, carbon nanotubes etc.), Fe, Zn, etc. are being heavily investigated for the enhancement of various properties (e.g., hy- drophobicity, anti-corrosivity etc.) of organic coatings, but their commercial application is limited mainly due to the dispersion and high cost-related issues [1–3]. An interface is Copyright: © 2021 by the author. Licensee MDPI, Basel, Switzerland. formed between the matrix and the surface of solid extender particles. It is believed that This article is an open access article the interfacial interactions (in the interphase region) between the matrix and the exten- distributed under the terms and der(s) play a major role in deciding the performance of an organic coating (or a composite) conditions of the Creative Commons during service. The interphase region is supposed to consist of two nanolayers, as shown Attribution (CC BY) license (https:// schematically in Figure1. The first nanolayer (around 1–20 Å from the surface of the creativecommons.org/licenses/by/ nanoparticle) contains polymer chains that are highly immobile due to strong attachment 4.0/). with the surface of the particles. The second nanolayer is thicker than the first one, which Solids 2021, 2, 108–120. https://doi.org/10.3390/solids2010006 https://www.mdpi.com/journal/solids Solids 2021, 1, FOR PEER REVIEW 2 consist of two nanolayers, as shown schematically in Figure 1. The first nanolayer Solids 2021, 2 (around 1–20 Å from the surface of the nanoparticle) contains polymer chains that are109 highly immobile due to strong attachment with the surface of the particles. The second nanolayer is thicker than the first one, which is formed around 25–90 Å away from the surface of the particles and contains polymer chains that are considered to be loosely is formed around 25–90 Å away from the surface of the particles and contains polymer boundchains to that the are nanoparticles. considered to Th bee looselythickness bound of the to interphase the nanoparticles. region depends The thickness upon ofpoly- the mer/matrixinterphase regiontype, dependssurface chemistry upon polymer/matrix of the extenders, type, surfacevolume chemistryfraction of of the the extenders,extenders used,volume particle fraction size of (and the distribution) extenders used, of the particle extenders size, (andand the distribution) quality of ofdispersion the extenders, of ex- tendersand the inside quality the of matrix dispersion [4–8] of. Properties extenders of inside the inte therphase matrix region [4–8]. are Properties known to of be the dif- in- ferentterphase from region the bulk are known of the topolymer. be different For example, from the bulka diffusion of the polymer.coefficient For of example,50 Å thick a filmdiffusion of polystyrene coefficient deposited of 50 Å thick on filmsilicon of polystyrenewafers was depositedfound to be on 1 silicon–2 orders wafers of magnitude was found lessto be than 1–2 ordersthat of of magnitudethe bulk polymer less than that[9]. ofThe the g bulklass polymertransition [9 ].temperature The glass transition (Tg) of Å poly(propylenetemperature (Tg )glycol) of poly(propylene confined in glycol) controlled confined pores in controlledof 100 poreswas found of 100 to Å wasbe higher found thanto be that higher of the than bulk that polymer of the bulk [10] polymer. [10]. FFigureigure 1. SchematicSchematic representation representation of inner and outer nanolayer formed in nanocomposites. Once closer to the surface of the (micrometer and/or nanometer) extender particles, Once closer to the surface of the (micrometer and/or nanometer) extender particles, the polymer chains can be tied strongly to the surface via a series of interactions devel- the polymer chains can be tied strongly to the surface via a series of interactions devel- oped via dangling tails, loops and adsorbed segments slowing down and broadening the oped via dangling tails, loops and adsorbed segments slowing down and broadening the segmental relaxation process. Segmental relaxations are related to the glass transition segmental relaxation process. Segmental relaxations are related to the glass transition temperature (Tg), which defines the flexibility of an organic coating (or composite) [11]. temperature (Tg), which defines the flexibility of an organic coating (or composite) [11]. Typically, the change (i.e., increase or decrease) in Tg of the filled polymers is attributed to Typically, the change (i.e., increase or decrease) in Tg of the filled polymers is attributed the nature of interactions (i.e., attractive, repulsive, or neutral) between the polymer and tothe the extender nature particles.of interaction Fors example, (i.e., attractive, attractive repulsive interactions, or neutral) (i.e., the between hydrogen the bonding)polymer andbetween the extender the hydroxyl particles groups. For example, of hydrophilic attractive silica interactions and carbonyl (i.e., groups the hydrogen of poly(vinyl bond- ing) between the hydroxyl groups of hydrophilic silica and carbonyl groups of acetate) have been shown to influence the Tg of the nanocomposite [5]. Similarly, covalent poly(vinyl acetate) have been shown to influence the Tg of the nanocomposite [5]. Simi- bonding between the filler surface and the resin has been shown to increase the Tg of the larly,composite covalent with bonding increasing between filler volumethe filler fraction surface inand the the composite resin has [12 been]. Covalent shown to bond in- creaseformation the betweenTg of the the composite particle surface with increasing and the polymer filler volume matrix can fraction be achieved in the bycomposite different [1ways2]. Covalent e.g., by the bond surface formation treatment between of the the extender particle particles surface with and a the polymer-reactive polymer matrix group, can bethe achieved addition by of chemicalsdifferent ways such ase.g., silanes by the to thesurface filled treatment system that of arethe capableextender of particle reactings withboth a with polymer the polymer-reactive and group the, extenderthe addition particles, of che ormicals by grafting such as the silanes polymer to the chains filled withsys- temfunctional that are groups, capable which of reacting can react both with with the the functional polymer and groups the presentextender on particles the surface,
Load more

Recommended publications
  • Exploiting Colloidal Interfaces to Increase Dispersion, Performance, and Pot-Life in Cellulose Nanocrystal/Waterborne Epoxy Composites
    Polymer 68 (2015) 111e121 Contents lists available at ScienceDirect Polymer journal homepage: www.elsevier.com/locate/polymer Exploiting colloidal interfaces to increase dispersion, performance, and pot-life in cellulose nanocrystal/waterborne epoxy composites Natalie Girouard a, Gregory T. Schueneman b, Meisha L. Shofner c, d, * J. Carson Meredith a, d, a School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA, USA b Forest Products Laboratory, U.S. Forest Service, One Gifford Pinchot Drive, Madison, WI, USA c School of Materials Science and Engineering, Georgia Institute of Technology, 771 Ferst Drive, Atlanta, GA, USA d Renewable Bioproducts Institute, Georgia Institute of Technology, 500 10th Street NW, Atlanta, GA, USA article info abstract Article history: In this study, cellulose nanocrystals (CNCs) are incorporated into a waterborne epoxy resin following two Received 23 February 2015 processing protocols that vary by order of addition. The processing protocols produce different levels of Received in revised form CNC dispersion in the resulting composites. The more homogeneously dispersed composite has a higher 2 May 2015 storage modulus and work of fracture at temperatures less than the glass transition temperature. Some Accepted 7 May 2015 properties related to the component interactions, such as thermal degradation and moisture content, are Available online 14 May 2015 similar for both composite systems. The mechanism of dispersion is probed with electrophoretic mea- surements and electron microscopy, and based on these results, it is hypothesized that CNC preaddition Keywords: Interfaces facilitates the formation of a CNC-coated epoxy droplet, promoting CNC dispersion and giving the Colloidal stability epoxide droplets added electrostatic stability.
    [Show full text]
  • Polymer-Particle Nanocomposites: Size and Dispersion Effects
    Polymer-Particle Nanocomposites: Size and Dispersion Effects Joseph Moll Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2012 ©2012 Joseph Moll All Rights Reserved ABSTRACT Polymer-Particle Nanocomposites: Size and Dispersion Effects Joseph Moll Polymer-particle nanocomposites are used in industrial processes to enhance a broad range of material properties (e.g. mechanical, optical, electrical and gas permeability properties). This dissertation will focus on explanation and quantification of mechanical property improvements upon the addition of nanoparticles to polymeric materials. Nanoparticles, as enhancers of mechanical properties, are ubiquitous in synthetic and natural materials (e.g. automobile tires, packaging, bone), however, to date, there is no thorough understanding of the mechanism of their action. In this dissertation, silica (SiO2) nanoparticles, both bare and grafted with polystyrene (PS), are studied in polymeric matrices. Several variables of interest are considered, including particle dispersion state, particle size, length and density of grafted polymer chains, and volume fraction of SiO2. Polymer grafted nanoparticles behave akin to block copolymers, and this is critically leveraged to systematically vary nanoparticle dispersion and examine its role on the mechanical reinforcement in polymer based nanocomposites in the melt state. Rheology unequivocally shows that reinforcement is maximized by the formation of a transient, but long-lived, percolating polymer-particle network with the particles serving as the network junctions. The effects of dispersion and weight fraction of filler on nanocomposite mechanical properties are also studied in a bare particle system. Due to the interest in directional properties for many different materials, different means of inducing directional ordering of particle structures are also studied.
    [Show full text]
  • Stimulus Methods of Multi-Functional Shape Memory Polymer
    Composites: Part A 100 (2017) 20–30 Contents lists available at ScienceDirect Composites: Part A journal homepage: www.elsevier.com/locate/compositesa Review Stimulus methods of multi-functional shape memory polymer nanocomposites: A review ⇑ ⇑ Tianzhen Liu a, Tianyang Zhou a, Yongtao Yao a, Fenghua Zhang a, Liwu Liu b, Yanju Liu b, , Jinsong Leng a, a Centre for Composite Materials and Structures, Harbin Institute of Technology (HIT), No. 2 YiKuang Street, PO Box 3011, Harbin 150080, People’s Republic of China b Department of Astronautical Science and Mechanics, Harbin Institute of Technology (HIT), No. 92 West Dazhi Street, PO Box 301, Harbin 150001, People’s Republic of China article info abstract Article history: This review is focused on the most recent research on multifunctional shape memory polymer nanocom- Received 19 February 2017 posites reinforced by various nanoparticles. Different multifunctional shape memory nanocomposites Received in revised form 22 April 2017 responsive to different kinds of stimulation methods, including thermal responsive, electro-activated, Accepted 28 April 2017 alternating magnetic field responsive, light sensitive and water induced SMPs, are discussed separately. Available online 2 May 2017 This review offers a comprehensive discussion on the mechanism, advantages and disadvantages of each actuation methods. In addition to presenting the micro- and macro- morphology and mechanical prop- Keywords: erties of shape memory polymer nanocomposites, this review demonstrates the shape memory perfor- Shape memory polymer mance and the potential applications of multifunctional shape memory polymer nanocomposites Nanocomposites Multifunctional under different stimulation methods. Actuation Ó 2017 Elsevier Ltd. All rights reserved. Contents 1. Introduction .......................................................................................................... 20 2. Thermo-responsive SMP nanocomposites.
    [Show full text]
  • Non-Spherical Nanoparticles in Block Copolymer Composites: Nanosquares, Nanorods and Diamonds
    Non-spherical nanoparticles in block copolymer composites: nanosquares, nanorods and diamonds Javier Diaz1, Marco Pinna∗1, Andrei V. Zvelindovsky1 and Ignacio Pagonabarragay2,3,4 1Centre for Computational Physics, University of Lincoln. Brayford Pool, Lincoln, LN6 7TS, UK 2Departament de F´ısicade la Mat`eriaCondensada, Universitat de Barcelona, Mart´ıi Franqu`es1, 08028 Barcelona, Spain 3 CECAM, Centre Europ´eende Calcul Atomique et Mol´eculaire, Ecole´ Polytechnique F´ed´eralede Lausanne, Batochime - Avenue Forel 2, 1015 Lausanne, Switzerland 4Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain October 28, 2019 For Table of Contents use only Abstract A hybrid block copolymer(BCP) nanocomposite computational model is proposed to study nanoparti- cles(NPs) with a generalised shape including squares, rectangles and rhombus. Simulations are used to study the role of anisotropy in the assembly of colloids within BCPs, ranging from NPs that are compat- ible with one phase, to neutral NPs. The ordering of square-like NPs into grid configurations within a minority BCP domain was investigated, as well as the alignment of nanorods in a lamellar-forming BCP, comparing the simulation results with experiments of mixtures of nanoplates and PS-b-PMMA BCP. The assembly of rectangular NPs at the interface between domains resulted in alignment along the interface. The aspect ratio is found to play a key role on the aggregation of colloids at the interface, which leads to a distinct co-assembly behaviour for low and high aspect ratio NPs. 1 Introduction Polymer nanocomposite materials containing anisotropic nanoparticles have attracted a lot of atten- tion due to their ability to create functional materials with enhanced properties 1.
    [Show full text]
  • Textile Nanocomposite of Polymer/Carbon Nanotube
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Ivy Union Publishing (E-Journals) American Journal of Nanoscience and Nanotechnology ResearchPage 1 of 8 A Kausar et al. American Journal of Nanoscience & Nanotechnology Research. 2018, 6:28-35 http://www.ivyunion.org/index.php/ajnnr 2017, 5:21-40 Research Article Textile Nanocomposite of Polymer/Carbon Nanotube Ayesha Kausar* School of Natural Sciences, National University of Sciences and Technology (NUST), H-12, Islamabad, Pakistan Abstract: Carbon nanotube (CNT) possess outstanding electrical, mechanical, anisotropic, and thermal properties to be employed in several material science applications. Polymer/carbon nanotube forms an important class of nanocomposites for textile uses. Different techniques have been used to develop such textiles including dip coating, spraying, wet spinning, electrospinning, etc. Enhanced nanocomposite performance has been attributed to synergistic effect of polymer and carbon nanotube nanofiller. Textile performance of polymer/CNT nanocomposite has been potentially important for flame retardant clothing, electromagnetic shielding wear, anti-bacterial fabric, flexible sensors, and waste water treatment. In this article, researches on application areas of polymer/CNT in textile industry has been reviewed. Modification of nanotube may lead to variety of further functional textiles with different high performance properties. Keywords: Polymer; carbon nanotube; nanocomposite; textile Received: May 26, 2018; Accepted: June 28, 2018; Published: July 22, 2018 Competing Interests: The author has declared that no competing interests exist. Copyright: 2018 Kausar A et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
    [Show full text]
  • A Review on Polymer Nanocomposites and Their Effective Applications in Membranes and Adsorbents for Water Treatment and Gas Separation
    membranes Review A Review on Polymer Nanocomposites and Their Effective Applications in Membranes and Adsorbents for Water Treatment and Gas Separation Oluranti Agboola 1,*, Ojo Sunday Isaac Fayomi 2, Ayoola Ayodeji 1, Augustine Omoniyi Ayeni 1 , Edith E. Alagbe 1, Samuel E. Sanni 1 , Emmanuel E. Okoro 3 , Lucey Moropeng 4, Rotimi Sadiku 4 , Kehinde Williams Kupolati 5 and Babalola Aisosa Oni 6 1 Department of Chemical Engineering, Covenant University, Ota PMB 1023, Nigeria; [email protected] (A.A.); [email protected] (A.O.A.); [email protected] (E.E.A.); [email protected] (S.E.S.) 2 Department of Mechanical Engineering, Covenant University, Ota PMB 1023, Nigeria; [email protected] 3 Department of Petroleum Engineering, Covenant University, Ota PMB 1023, Nigeria; [email protected] 4 Department of Chemical, Metallurgical and Materials Engineering, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa; [email protected] (L.M.); [email protected] (R.S.) 5 Department of Civil Engineering, Tshwane University of Technology, Private Bag X680, Pretoria 0001, South Africa; [email protected] 6 Department of Chemical Engineering and Technology, China University of Petroleum, Beijing 102249, China; [email protected] * Correspondence: [email protected] Abstract: Globally, environmental challenges have been recognised as a matter of concern. Among Citation: Agboola, O.; Fayomi, O.S.I.; these challenges are the reduced availability and quality of drinking water, and greenhouse gases Ayodeji, A.; Ayeni, A.O.; Alagbe, E.E.; that give rise to change in climate by entrapping heat, which result in respirational illness from smog Sanni, S.E.; Okoro, E.E.; Moropeng, L.; and air pollution.
    [Show full text]
  • Electrospun Polyacrylonitrile Nanocomposite Fibers Reinforced
    Polymer 50 (2009) 4189–4198 Contents lists available at ScienceDirect Polymer journal homepage: www.elsevier.com/locate/polymer Electrospun polyacrylonitrile nanocomposite fibers reinforced with Fe3O4 nanoparticles: Fabrication and property analysis Di Zhang a, Amar B. Karki b, Dan Rutman a, David P. Young b, Andrew Wang c, David Cocke a, Thomas H. Ho a, Zhanhu Guo a,* a Integrated Composites Laboratory (ICL), Dan F. Smith Department of Chemical Engineering, Lamar University, Beaumont, TX 77710, USA b Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803, USA c Ocean NanoTech, LLC, 2143 Worth Ln., Springdale, AR 72764, USA article info abstract Article history: The manufacturing of pure polyacrylonitrile (PAN) fibers and magnetic PAN/Fe3O4 nanocomposite fibers is Received 12 June 2009 explored by an electrospinning process. A uniform, bead-free fiber production process is developed by Accepted 20 June 2009 optimizing electrospinning conditions: polymer concentration, applied electric voltage, feedrate, and Available online 30 June 2009 distance between needle tip to collector. The experiments demonstrate that slight changes in operating parameters may result in significant variations in the fiber morphology. The fiber formation mechanism for Keywords: both pure PAN and the Fe3O4 nanoparticles suspended in PAN solutions is explained from the rheologial Nanocomposite fibers behavior of the solution. The nanocomposite fibers were characterized by scanning electron microscopy Electrospinning Polyacronitrile (PAN) (SEM), Fourier transform infrared (FT-IR) spectrophotometer, and X-ray diffraction (XRD). FT-IR and XRD results indicate that the introduction of Fe3O4 nanoparticles into the polymer matrix has a significant effect on the crystallinity of PAN and a strong interaction between PAN and Fe3O4 nanoparticles.
    [Show full text]
  • Introducing a Novel Low Energy Gamma Ray Shield Utilizing
    www.nature.com/scientificreports OPEN Introducing a novel low energy gamma ray shield utilizing Polycarbonate Bismuth Oxide composite Rojin Mehrara1, Shahryar Malekie2, Seyed Mohsen Saleh Kotahi1 & Sedigheh Kashian2* The fabrication of diferent weight percentages of Polycarbonate-Bismuth Oxide composite (PC-Bi2O3), namely 0, 5, 10, 20, 30, 40, and 50 wt%, was done via the mixed-solution method. The dispersion state of the inclusions into the polymeric matrix was studied through XRD and SEM analyses. Also, TGA and DTA analyses were carried out to investigate the thermal properties of the samples. Results showed that increasing the amount of Bi2O3 into the polymer matrix shifted the glass transition temperature of the composites towards the lower temperatures. Then, the amount of mass attenuation coefcients of the samples were measured using a CsI(Tl) detector for diferent gamma rays of 241Am, 57Co, 99mTc, and 133Ba radioactive sources. It was obtained that increasing the concentration of the Bi2O3 fllers in the polycarbonate matrix resulted in increasing the attenuation coefcients of the composites signifcantly. The attenuation coefcient was enhanced twenty-three times for 50 wt% composite in 59 keV energy, comparing to the pure polycarbonate. X and γ-rays have a wide range of applications in military, medical, health, scientifc, and agricultural industries. Increasing the utilization of hazardous radiations, including gamma sources in hospitals and research centers for diagnostic and therapeutic applications, has provided a much more unsecured place for personnel. So there will be a need to design an appropriate shield, depends on the type of ionizing radiation, to reduce the radiation dose in the intended site1.
    [Show full text]
  • Michael R. Bockstaller
    Michael R. Bockstaller Professor, Department of Materials Science & Engineering, Carnegie Mellon University, Pittsburgh PA 15213. Phone: (412) 268-2709; Fax: (412) 268-7247; E-mail: [email protected] Professional Preparation University of Karlsruhe, Karlsruhe (Germany) Chemistry (Diplom) 1990-1996 Johannes Gutenberg University, Mainz (Germany) Chemistry (Dr. rer. nat.) 2000-2005 Postdoctoral Associate, MIT, Cambridge MA Mat. Sci. & Eng. 2000-2004 Lecturer, RWTH Aachen, Aachen (Germany) Chemistry 2004-2005 Appointments 07/14 – present Professor, Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 03/11 – present Adjunct Professor, Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213 07/10 – 06/14 Associate Professor, Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 4/05 – 05/10 Assistant Professor, Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213 3/04 – 3/05 Emmy-Noether Research Group Leader, Department of Technical and Macromolecular Chemistry, RWTH Aachen University, Aachen (Germany) 7/00 – 2/04 Postdoctoral Associate, Department of Materials Science and Engineering, MIT, Cambridge, 02139 MA 4/99 – 12/99 Visiting Scientist, Foundation of Research and Technology Hellas - Institute for Electronic Structure and Laser Technology, Iraklion (Greece) 1/98 – 12/98 Teaching Assistant, Dept. of Chemistry., Johannes Gutenberg University, Mainz (Germany) 9/97 – 7/00 Research Assistant, Max-Planck Institute for Polymer Research, Mainz (Germany) Awards and Honors 2014 Fellow of the American Physical Society 2008 The Philbrook Prize (by the Department of Materials Science and Engineering) 2003 Emmy Noether grant recipient of the German Science Foundation 2000 Feodor-Lynen fellowship award by Alexander von Humboldt Foundation Membership and Activities in Honorary Fraternities, Professional Societies 1.
    [Show full text]
  • Effect of Copolymer Sequence on Local Viscoelastic Properties in Spherical
    Effect of copolymer sequence on local viscoelastic properties in spherical coordinates around a nanoparticle Mitchell F. Wendt,y Advisors: Alex J. Trazkovich,y,z and Lisa M. Hall∗,y yWilliam G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, 140 W 19th Ave., Columbus, OH 43210 zSEA Limited, 7001 Buffalo Parkway, Columbus, OH 43229 E-mail: [email protected],[email protected],[email protected] Abstract A polymer nanocomposite consisting of a spherical nanoparticle surrounded by coarse-grained polymer chains is simulated. Two monomer types make up the poly- mers, differing only in their interactions with the nanoparticle. All atomic stress fluctu- ations are measured, converted to spherical coordinates centered around the nanopar- ticle, and used to estimate the local stress autocorrelation as a function of distance from the nanoparticle. The local stress autocorrelation is substituted into the relation- ship between the bulk stress autocorrelation and bulk dynamic modulus, analyzed in both radial shear and tangential shear geometries. The result is then treated as an es- timate of the local dynamic modulus. This allows us to separate radial and tangential effects on overall dynamic modulus as a function of distance from the nanoparticle for multiple copolymer sequences. Unlike the direction-independent results, short block length copolymer sequences exhibit a non-monotonic progression of the magnitude of the tan(δ) (hysteresis) peak over distance to the nanoparticle, suggesting that adjusting copolymer sequence could significantly control observed nanocomposite dynamics. 1 Introduction Note: Some text and figures are adapted and reprinted with permission from A.J. Trazkovich.; M.F.Wendt.; L.M.
    [Show full text]
  • Smart Polymers in Micro and Nano Sensory Devices
    chemosensors Review Smart Polymers in Micro and Nano Sensory Devices José Antonio Reglero Ruiz * ID , Ana María Sanjuán, Saúl Vallejos, Félix Clemente García and José Miguel García ID Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Burgos, Plaza Misael Bañuelos s/n, 09001 Burgos, Spain; [email protected] (A.M.S.); [email protected] (S.V.); [email protected] (F.C.G.); [email protected] (J.M.G.) * Correspondence: [email protected]; Tel.: +34-947-258-085 Received: 25 February 2018; Accepted: 19 March 2018; Published: 21 March 2018 Abstract: The present review presents the most recent developments concerning the application of sensory polymers in the detection and quantification of different target species. We will firstly describe the main polymers that are being employed as sensory polymers, including, for example, conducting or acrylate-based polymers. In the second part of the review, we will briefly describe the different mechanisms of detection and the target species, such as metal cations and anions, explosives, and biological and biomedical substances. To conclude, we will describe the advancements in recent years concerning the fabrication of micro and nano sensory devices based on smart polymers, with a bibliographic revision of the research work published between 2005 and today, with special emphasis on research work presented since 2010. A final section exposing the perspectives and challenges of this interesting research line will end the present review article. Keywords: sensors; smart polymers; detection; sensory devices 1. Introduction Sensory or smart polymers present the ability to respond, reversibly or irreversibly, to different stimuli. Different sources can cause these responses: Temperature [1], electromagnetic pulses [2], biological molecules [3] or Ph media [4].
    [Show full text]
  • Intelligent Polymers, Fibers and Applications
    polymers Review Intelligent Polymers, Fibers and Applications Li Jingcheng , Vundrala Sumedha Reddy, Wanasinghe A. D. M. Jayathilaka , Amutha Chinnappan, Seeram Ramakrishna * and Rituparna Ghosh * Department of Mechanical Engineering, Centre for Nanotechnology & Sustainability, National University of Singapore, Singapore 117574, Singapore; [email protected] (L.J.); [email protected] (V.S.R.); [email protected] (W.A.D.M.J.); [email protected] (A.C.) * Correspondence: [email protected] (S.R.); [email protected] (R.G.) Abstract: Intelligent materials, also known as smart materials, are capable of reacting to various external stimuli or environmental changes by rearranging their structure at a molecular level and adapting functionality accordingly. The initial concept of the intelligence of a material originated from the natural biological system, following the sensing–reacting–learning mechanism. The dynamic and adaptive nature, along with the immediate responsiveness, of the polymer- and fiber-based smart materials have increased their global demand in both academia and industry. In this manuscript, the most recent progress in smart materials with various features is reviewed with a focus on their applications in diverse fields. Moreover, their performance and working mechanisms, based on different physical, chemical and biological stimuli, such as temperature, electric and magnetic field, deformation, pH and enzymes, are summarized. Finally, the study is concluded by highlighting the existing challenges and future opportunities in the field of intelligent materials. Keywords: intelligent materials; stimuli-responsive; polymers Citation: Jingcheng, L.; Reddy, V.S.; Jayathilaka, W.A.D.M.; Chinnappan, A.; Ramakrishna, S.; Ghosh, R. Intelligent Polymers, Fibers and 1. Introduction Applications.
    [Show full text]