DOCSLIB.ORG

Conducting Properties of Polypropylene/ Carbon Nanofiber Composites

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Conducting Properties of Polypropylene/ Carbon Nanofiber Composites 16TH INTERNATIONAL CONFERENCE ON COMPOSITE MATERIALS CONDUCTING PROPERTIES OF POLYPROPYLENE/ CARBON NANOFIBER COMPOSITES W. H. Zhong, G. Sui, M. A. Fuqua and C. A. Ulven Department of Mechanical Engineering North Dakota State University, Fargo, ND 58105, USA Keywords: carbon nanofibers, polypropylene, nanocomposites, conductivity Abstract particular, very few have reported work Effects of carbon nanofibers (CNFs) on addressing the effects of CNFs on the final the microstructure and properties of semi- properties of the resulting nanocomposites crystalline polymers were studied based on through the crystallization behavior of the preparation of polypropylene (PP) polymer matrix. nanocomposites by a twin-screw extrusion. As an effective processing method, twin- Crystallization behavior and morphology, as screw extrusion can play an important role in well as dielectric property, thermal and preparing of nanocomposites to obtain electrical conductivity of the CNF/PP nanocomposites with uniform microstructure nanocomposites were characterized. The [4-6]. degree of crystallinity of the PP exhibited an This paper introduces the preparation increased trend with addition of CNFs carbon nanofiber/PP nanocomposites by a followed by moderate decreases at higher Micro-18mm twin-screw extruder which can content. The PP nanocomposite containing provide the high shear compounding for 5wt% CNFs exhibited a surprisingly high polymer melts. After a great deal of dielectric constant under wide sweep exploring experiments, the optimal extruding frequencies attended by low dielectric loss. procedures for carbon nanofiber/PP With the increasing of CNF content, nanocomposites were established. The aim of electrical and thermal conductivities of the present work is to study the effects of nanocomposites were enhanced continuously. carbon nanofiber content on crystallization behavior, mechanical properties, thermal 1. Introduction conductivity, and electrical conductivity of As one of the most widely used plastics the PP matrix. in large volume, polypropylene (PP) has a number of desirable properties, such as high 2. Experimental chemical resistance, good mechanical 2.1 Materials properties, fine processability and low cost. The PP was supplied by Formosa To enhance low thermal stability and Plastics Corporation, USA under the trade strength of PP, people have tried to apply name Formolene 5100H and had a density of novel additives and processing technology. 0.91kg/m3. CNFs used for nanocomposites Although numerous investigations were preparation were supplied by Pyrograf carried out on crystallization of PP Products, Inc., OH, USA under the trade composites [1-3], few studies have been name Pyrograf Ⅲ® Carbon fiber. The reported related to overall influences of average fiber diameter vary from 20nm to CNFs on the semi-crystalline polymers. In 200nm, and CNF content is ＞98%. The as- received CNFs was dipped in hydrofluoric 3 Results and discussion acide for 24h to get rid of impurities, and 3.1. Morphological studies then CNFs was carefully washed and filtrated The DSC thermogram of the neat PP with deionized water until the pH level of the and CNF/PP composite specimens is shown solution reached 6. Purified CNFs were dried in Fig.1. prior to use for 24h in a vacuum oven to remove moisture. To avoid the effect of PP+5wt% CNFs chemical reagent on the analyses results, only purified and dried CNFs were used and no PP+3wt% CNFs ow other surface treatments were made in Fl PP+1wt% CNFs experiment. at He Neat PP 2.2. Preparation of the CNF/PP composites The CNFs up to 5wt% loading were hermal melt-compounded with PP in a co-rotating Exot Leistritz Micro-18/GL-40D twin-screw 100 125 150 175 200 extruder manufactured by Brabender Temperature(℃) Technologie Inc, Germany. The screw rotation rate was set at 75 rpm, and the Fig.1 DSC curves of neat PP and CNF/PP temperature profile from hopper to die was as composites follows: 182°C, 188°C, 193°C, 199°C, 204°C, 210°C, 210°C, 210°C. The extruded The Tm (peak temperature of PP and composites were pelletized and then crystallization melting), and ∆Hm (melting compression molded at 200°C to obtain test heat of crystallization) are listed in Table 1. specimens. The degree of crystallinity of a specimen can be calculated from the melting heat of 2.3. Characterizations of the materials crystallization according to the following Differential scanning calorimetry equation: analysis was performed using TA ∆H m X c = Instruments DSC Q1000 in a nitrogen ∆H 0 atmosphere. The specimens were heated at a Where ∆H0 = 207.1J/g is the melting heat of rate of 10°C/min to 250°C. The morphology 100% crystalline PP [7]. When increasing the of the fracture interface of neat epoxy and loading of the CNFs, the peak temperature of composite specimens was observed by a crystallization melting of specimens was JEOL JSM-6300 model scanning electron almost independent of CNF loading. The microscopy. The dielectric measurements of calculated degree of crystallinity of the samples were carried out at room specimens exhibited an increased trend with temperature using a Novocontrol increasing CNF load, followed by a moderate Technologies Alpha-N high resolution decrease at 5wt% content of CNFs. It was Dielectric Analyzer made in Germany. implied that as the CNFs were added into the Electrical conductivities of specimens were PP matrix, the lower loading of nanofibers tested using a Keithley 6517A could facilitate the mobility of the PP electrometer/high resistance meter at room macromolecular chains. Nanofibers brought temperature. A Keithley 8009 resistivity test heterogeneous nucleation effects fixture is connected. Thermal conductivity simultaneously, thus the degree of performances of samples were tested using a crystallinity of specimens increased. As the Mathis TC-30 Thermal Conductivity content of nanofibers increased, the Instrument at room temperature. nanofibers started to obstruct the mobilization of the macromolecular chains 2 and prevented macromolecular segments from obtaining ordered alignment of the crystal lattice. The degree of crystallinity of specimens decreased accordingly. Table 1 Crystallization parameters of neat PP and CNF/PP composites Tm(°C) ∆Hm(J/g) Xc(%) PP+5wt% 164.68 91.11 43.99 CNFs PP+3wt% 165.25 96.78 46.73 CNFs (b) PP + 3wt% CNFs PP+1wt% 164.29 93.08 44.94 CNFs Neat PP 165.39 87.46 42.23 Fig.2 shows the micro-morphology of the CNF/PP composites prepared in experiments. Generally, nanofillers with high aspect ratios, such as nanofibers, are difficult to uniformly disperse within polymer matrices due to their high surface areas. The CNF/PP nanocomposites prepared for this study showed no obvious agglomerations (c) PP + 5wt% CNFs however, suggesting that the nanofibers were dispersed uniformly in the PP matrix by Fig.2 Micro-morphology of CNF/PP means of the twin-screw extrusion. The composites micro-morphology of the nanocomposites containing 5wt% CNFs presented different This is consistent with the DSC test results features from other specimens. It can be which showed the crystallization degree to be observed that plastic deformation was lower with the addition of 5wt% of CNFs. prevalent in this nanocomposite, which is thought to be the result of both a stronger 3.2. Dielectric properties reinforcing effect from the high Dielectric constant showed the ability of concentration of CNFs and higher amorphous a material to store electric potential energy portions of the PP inside this nanocomposite. under the influence of an electric field. In Fig.3 the effects of CNF loading on the dielectric constant under various applied sweep frequencies is shown. The dielectric constant of the neat polymer exhibited low frequency dependence, but with the addition of CNFs, the frequency dependence was gradually increased. Compared to neat PP, the addition of CNFs initially caused a decrease in the overall level of the dielectric constant. However, further loading to 5wt% CNFs saw the dielectric constant increase to a level much greater than that of the neat (a) PP + 1wt% CNFs polymer. 3 3 10 variation of dielectric constant with frequency indicates the presence of an interfacial polarization in PP matrix. This tant 2 10 Neat PP gradually decreasing dielectric constant with PP+1wt% CNFs PP+3wt% CNFs increased frequency is thought to be caused ic cons PP+5wt% CNFs by the slow dielectric relaxation of the matrix 101 resin and the interface of the composite. The Dielectr value scale and stabilization of dielectric constant obtained in this work is comparable 100 with other reported dielectric materials, even -3 -2 -1 0 1 2 3 4 5 6 7 10 10 10 10 10 10 10 10 10 10 10 is more remarkable and practical [9-12]. Frequency (Hz) The loss factor of the dielectric constant of neat PP and the CNF/PP composites under Fig.3 Dielectric constants vs. frequency various applied sweep frequencies is shown in Fig.4. Except for the PP matrix containing The experimental declines seen for PP 5wt% CNFs, the loss factor of the samples all composites with 1wt% and 3wt% CNF exhibited initial decreases with increased loading were suspected to be result of both frequency, followed by an increase to a an improvement in conductivity of the certain frequency. However, for the PP composite (which will be shown in the next nanocomposites containing 5wt% CNFs, the section), and the increased degree of loss factor increased with frequency at low crystallinity in the specimens, which affected frequency, and a peak of loss factor appeared the dipole polarization of the groups and around 3Hz. The first increase of loss factor segments. From this study, it is reasonable to at low frequency can be attributed to dipole consider that the crystal characteristic of polarization [8]. As the frequency further polymer matrix is also an important factor increased, the dipole polarization effects influencing the dielectric property of reduced and the value of the loss factor composite.
Load more

Recommended publications
  • Questions: Physical Properties and 7 Step Process
    Questions: Physical Properties and 7 Step Process 1. Why does a water-saturated sandstone typically have a higher P-wave velocity than a dry sandstone? A saturated sandstone: a. is more dense b. has a larger bulk modulus c. has a larger shear modulus d. has a higher tensile strength 2. The relative permittivity of a given rock is considered large when: a. it contains a lot of pore water b. an applied electric field results in a larger electric dipole moment c. it has a value of 30 d. b and c are correct e. a,b and c are correct 3. You measure a resistance of 16 kΩ between two parallel faces of a 2cm x 2cm x 2cm cube. Determine the resistivity. a. 320 Ωm b. 800000 Ωm c. 32000 Ωm d. 8000 Ωm 4. You are flying a gravity survey over a sedimentary basin. The flight path crosses a known dyke. What would be the expected gravity response and why? a. Gravity high over the dyke; the dyke is more dense than the background b. Gravity low over the dyke; the dyke is less dense than the background c. Gravity high over the dyke; the dyke is less dense than the background d. Gravity low over the dyke; the dyke is more dense than the background 5. You are building a road through known active Karst terrain in Ireland. Which set of physical property contrasts would be most diagnostic for locating regions where sink- holes could form? a. Karstified: low density, Limestone: high density b. Karstified: low resistivity, Limestone: high resistivity c.
    [Show full text]
  • AC Measurement System (ACMS) Option User's Manual
    Physical Property Measurement System AC Measurement System (ACMS) Option User’s Manual Part Number 1084-100 C-1 Quantum Design 11578 Sorrento Valley Rd. San Diego, CA 92121-1311 USA Technical support (858) 481-4400 (800) 289-6996 Fax (858) 481-7410 Fourth edition of manual completed June 2003. Trademarks All product and company names appearing in this manual are trademarks or registered trademarks of their respective holders. U.S. Patents 4,791,788 Method for Obtaining Improved Temperature Regulation When Using Liquid Helium Cooling 4,848,093 Apparatus and Method for Regulating Temperature in a Cryogenic Test Chamber 5,311,125 Magnetic Property Characterization System Employing a Single Sensing Coil Arrangement to Measure AC Susceptibility and DC Moment of a Sample (patent licensed from Lakeshore) 5,647,228 Apparatus and Method for Regulating Temperature in Cryogenic Test Chamber 5,798,641 Torque Magnetometer Utilizing Integrated Piezoresistive Levers Foreign Patents U.K. 9713380.5 Apparatus and Method for Regulating Temperature in Cryogenic Test Chamber CONTENTS Table of Contents PREFACE Contents and Conventions ...............................................................................................................................vii P.1 Introduction .......................................................................................................................................................vii P.2 Scope of the Manual..........................................................................................................................................vii
    [Show full text]
  • Lab 1 - Physical Properties of Minerals
    Page - Lab 1 - Physical Properties of Minerals All rocks are composed of one or more minerals. In order to be able to identify rocks you have to be able to recognize those key minerals that make of the bulk of rocks. By definition, any substance is classified as a mineral if it meets all 5 of the following criteria: - is naturally occurring (ie. not man-made); - solid (not liquid or gaseous); - inorganic (not living and never was alive); - crystalline (has an orderly, repetitive atomic structure); - a definite chemical composition (you can write a discrete chemical formula for any mineral). Identifying an unknown mineral is like identifying any group of unknowns (leaves, flowers, bugs... etc.) You begin with a box, or a pile, of unknown minerals and try to find any group features in the samples that will allow you to separate them into smaller and smaller piles, until you are down to a single mineral and a unique name. For minerals, these group features are called physical properties. Physical properties are any features that you can use your 5 senses (see, hear, feel, taste or smell) to aid in identifying an unknown mineral. Mineral physical properties are generally organized in a mineral key and the proper use of this key will allow you to name your unknown mineral sample. The major physical properties will be discussed briefly below in the order in which they are used to identify an unknown mineral sample. Luster Luster is the way that a mineral reflects light. There are two major types of luster; metallic and non-metallic luster.
    [Show full text]
  • Properties of Matter
    Properties of Matter Say Thanks to the Authors Click http://www.ck12.org/saythanks (No sign in required) To access a customizable version of this book, as well as other interactive content, visit www.ck12.org CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the FlexBook®, CK-12 intends to pioneer the generation and distribution of high-quality educational content that will serve both as core text as well as provide an adaptive environment for learning, powered through the FlexBook Platform®. Copyright © 2013 CK-12 Foundation, www.ck12.org The names “CK-12” and “CK12” and associated logos and the terms “FlexBook®” and “FlexBook Platform®” (collectively “CK-12 Marks”) are trademarks and service marks of CK-12 Foundation and are protected by federal, state, and international laws. Any form of reproduction of this book in any format or medium, in whole or in sections must include the referral attribution link http://www.ck12.org/saythanks (placed in a visible location) in addition to the following terms. Except as otherwise noted, all CK-12 Content (including CK-12 Curriculum Material) is made available to Users in accordance with the Creative Commons Attribution/Non- Commercial/Share Alike 3.0 Unported (CC BY-NC-SA) License (http://creativecommons.org/licenses/by-nc-sa/3.0/), as amended and updated by Creative Commons from time to time (the “CC License”), which is incorporated herein by this reference.
    [Show full text]
  • Dielectric Properties and Other Physical Properties of Low-Acyl Gellan Gel As Relevant to Microwave Assisted Pasteurization Proc
    Journal of Food Engineering 149 (2015) 195–203 Contents lists available at ScienceDirect Journal of Food Engineering journal homepage: www.elsevier.com/locate/jfoodeng Dielectric properties and other physical properties of low-acyl gellan gel as relevant to microwave assisted pasteurization process ⇑ Wenjia Zhang a, Donglei Luan a, Juming Tang a, , Shyam S. Sablani a, Barbara Rasco b, Huimin Lin a, Fang Liu a a Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, United States b UI/WSU bi-State School of Food Science and Human Nutrition, Washington State University, Pullman, WA 99164-6120, United States article info abstract Article history: Various model foods were needed as chemical marker carriers for the heating pattern determination in Received 1 April 2014 developing microwave heating processes. It is essential that these model foods have matching physical Received in revised form 5 October 2014 properties with the food products that will be microwave processed, such as meat, vegetables, pasta, Accepted 13 October 2014 etc. In this study, the physical properties of low acyl gellan gel were investigated to evaluate its suitability Available online 22 October 2014 to be used as a possible model food for the development of single mode 915 MHz microwave assisted pasteurization processes. These physical properties included the dielectric properties, gel strength and Keywords: water holding capacities. In order to adjust the dielectric constant and loss factor, various amounts of Low acyl gellan gel sucrose (0, 0.1, 0.3 and 0.5 g/mL (solution)) and salt (0, 100, 200, and 300 mM) were added to 1% gellan Dielectric properties 2+ Gel strength gel (with 6 mM Ca addition).
    [Show full text]
  • PROPERTIES of MATERIALS This Page Intentionally Left Blank Properties of Materials Anisotropy, Symmetry, Structure
    PROPERTIES OF MATERIALS This page intentionally left blank Properties of Materials Anisotropy, Symmetry, Structure ROBERT E. NEWNHAM Pennsylvania State University 1 3 Great Clarendon Street, Oxford OX26DP Oxford University Press is a department of the University of Oxford. It furthers the University’s objective of excellence in research, scholarship, and education by publishing worldwide in Oxford New York Auckland Bangkok Buenos Aires Cape Town Chennai Dar es Salaam Delhi Hong Kong Istanbul Karachi Kolkata Kuala Lumpur Madrid Melbourne Mexico City Mumbai Nairobi São Paulo Shanghai Taipei Tokyo Toronto Oxford is a registered trade mark of Oxford University Press in the UK and in certain other countries Published in the United States by Oxford University Press Inc., New York © Oxford University Press 2005 The moral rights of the authors have been asserted Database right Oxford University Press (maker) First published 2005 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press, or as expressly permitted by law, or under terms agreed with the appropriate reprographics rights organization. Enquiries concerning reproduction outside the scope of the above should be sent to the Rights Department, Oxford University Press, at the address above You must not circulate this book in any other binding or cover and you must impose this same condition on any acquirer British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Data available ISBN 0-19-852075-1 (hbk) ISBN 0-19-852076-x (pbk) 10987654321 Typeset by Newgen Imaging Systems (P) Ltd., Chennai, India Printed in Great Britain on acid-free paper by Antony Rowe, Chippenham Preface This book is about anisotropy and structure–property relationships.
    [Show full text]
  • Engineering Properties of Foods - Barbosa-Cánovas G.V., Juliano P
    FOOD ENGINEERING – Vol. I - Engineering Properties of Foods - Barbosa-Cánovas G.V., Juliano P. and Peleg M. ENGINEERING PROPERTIES OF FOODS Barbosa-Cánovas G.V. and Juliano P. Washington State University, USA Peleg M. University of Massachusetts, USA Keywords: Food engineering, engineering property, physical, thermal, heat, electrical, foods, density, porosity, shrinkage, particulates, powders, compressibility, flowability, conductivity, permittivity, dielectric, color, gloss, translucency, microstructure, microscopy, diffusivity, texture Contents 1. Introduction 2. Thermal Properties 2.1. Definitions 2.2. Thermal Variations in Properties and Methods of Determination 2.3. Food Processing Applications 3. Optical Properties 3.1 Definitions 3.2. Methods and Applications 4. Electrical Properties 4.1. Electrical Conductivity and Permittivity 4.2. Methods and Applications 5. Mechanical Properties 5.1. Structural and Geometrical Properties 5.1.1. Density 5.1.2. Porosity 5.1.3. Shrinkage 5.2. Rheology and Texture 6. Properties of Food Powders 6.1. Primary Properties 6.2. Secondary Properties 7. Role ofUNESCO Food Microstructure in Engineering – EOLSSProperties 7.1. Structural Characterization of Foods 7.2. Practical Implications Glossary SAMPLE CHAPTERS Bibliography Biographical Sketches Summary The engineering properties of foods are important, if not essential, in the process design and manufacture of food products. They can be classified as thermal (specific heat, thermal conductivity, and diffusivity), optical (color, gloss, and translucency), electrical (conductivity and permittivity), mechanical (structural, geometrical, and strength), and ©Encyclopedia of Life Support Systems (EOLSS) FOOD ENGINEERING – Vol. I - Engineering Properties of Foods - Barbosa-Cánovas G.V., Juliano P. and Peleg M. food powder (primary and secondary) properties. Most of these properties indicate changes in the chemical composition and structural organization of foods ranging from the molecular to the macroscopic level.
    [Show full text]
  • Physical Properties As Indicators of Liquid Compositions: Derivation of the Composition for Titan’S Surface Liquids from the Huygens SSP Measurements A
    Mon. Not. R. Astron. Soc. 359, 637–642 (2005) doi:10.1111/j.1365-2966.2005.08935.x Physical properties as indicators of liquid compositions: Derivation of the composition for Titan’s surface liquids from the Huygens SSP measurements A. Hagermann,1 J. C. Zarnecki,1 M. C. Towner,1 P. D. Rosenberg,1 R. D. Lorenz,2 M. R. Leese,1 B. Hathi1 and A. J. Ball1 1Planetary and Space Sciences Research Institute, The Open University, Walton Hall, Milton Keynes MK7 6AA 2Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721-0092, USA Accepted 2005 February 15. Received 2005 February 15; in original form 2004 November 23 ABSTRACT We present a method for inferring the relative molar abundance of constituents of a liquid mixture, in this case methane, ethane, nitrogen and argon, from a measurement of a set of physical properties of the mixture. This problem is of interest in the context of the Huygens Surface Science Package, SSP, equipped to measure several physical properties of a liquid in case of a liquid landing on Saturn’s moon Titan. While previous models emphasized the possibility of verifying a certain model proposed by atmospheric composition and equations of state, we use an inverse approach to the problem, i.e. we will infer the liquid composition strictly from our measurements of density, refractive index, permittivity, thermal conductivity and speed of sound. Other a priori information can later be used to improve (or reject) the model obtained from these measurements. Keywords: instrumentation: miscellaneous – methods: numerical – techniques: miscella- neous – planets and satellites: individual: Titan.
    [Show full text]
  • Thermodynamics
    Thermodynamics (Chapters 17–20) Temperature and Kinetic Gas Theory (Chapter 17) The temperature of an object is a measure of its average internal molecular kinetic energy. A consistent temperature scale can be defined in terms of properties of gases at low densities. Thermal Equilibrium and Temperature: Our sense of touch tells us if an object is hot or cold. A physical property that changes with temperature is called thermometric property. If we place a warm and a cold object into thermal contact, the cold object warms and the warm object cools. Eventually, this process stops and the two objects are said to be in thermal equilibrium and the two objects are then defined to have the same temperature. The zeroth law of thermodynamics: If two objects are in thermal equilibrium with a third, then they are also in thermal equilibrium with one another. 1 The Celsius and the Fahrenheit Temperature Scales Any thermometric property can be used to establish a temperature scale. The common mercury thermometer consists of a glass bulb and tube containing a fixed amount of mercury. When the thermometer is put in contact with a warmer body, the mercury expands, increasing the length of the mercury column (the glass expands by a negligible amount). The ice point temperature or normal freezing point of water is the freezing point of water at a pressure of 1 atm. The steam-point temperature or normal boiling point of water is the the boiling point of water at a pressure of 1 atm. Units of pressure: Pascal (Pa): 1 Pa = 1 N/m2, atmosphere (atm): 1 atm = 101.325 kPa = 14.70 lb/in2, millimeters of mercury (mmHg) in a U-tube barometer (Figures 13-6 and 13-7 of Tipler-Mosca), a unit called torr: 1 atm = 760 mmHg .
    [Show full text]
  • Definition of the Ideal Gas
    ON THE DEFINITION OF THE IDEAL GAS. By Edgar Bucidngham. I . Nature and purpose of the definition.—The notion of the ideal gas is that of a gas having particularly simple physical properties to which the properties of the real gases may be considered as approximations; or of a standard to which the real gases may be referred, the properties of the ideal gas being simply defined and the properties of the real gases being then expressible as the prop- erties of the standard plus certain corrections which pertain to the individual gases. The smaller these corrections the more nearly the real gas approaches to being in the "ideal state." This con- ception grew naturally from the fact that the earlier experiments on gases showed that they did not differ much in their physical properties, so that it was possible to define an ideal standard in such a way that the corrections above referred to should in fact all be ''small" in terms of the unavoidable errors of experiment. Such a conception would hardly arise to-day, or if it did, would not be so simple as that which has come down to us from earlier times when the art of experimenting upon gases was less advanced. It is evident that a quantitative definition of the ideal standard gas needs to be more or less complete and precise according to the nature of the problem under immediate consideration. If changes of temperature and of internal energy play no part, all that is usually needed is a standard relation between pressure and volume.
    [Show full text]
  • Properties of Gases
    1 Properties of Gases Dr Claire Vallance First year, Hilary term Suggested Reading Physical Chemistry, P. W. Atkins Foundations of Physics for Chemists, G. Ritchie and D. Sivia Physical Chemistry, W. J. Moore University Physics, H. Benson Course synopsis 1. Introduction - phases of matter 2. Characteristics of the gas phase Examples Gases and vapours 3. Measureable properties of gases Pressure Measurement of pressure Temperature Thermal equilibrium and temperature measurements 4. Experimental observations – the gas laws The relationship between pressure and volume The effect of temperature on pressure and volume The effect of the amount of gas Equation of state for an ideal gas 5. Ideal gases and real gases The ideal gas model The compression factor Equations of state for real gases 6. The kinetic theory of gases 7. Collisions with the container walls – determining pressure from molecular speeds 8. The Maxwell Boltzmann distribution revisited Mean speed, most probable speed and rms speed of the particles in a gas 9. Collisions (i) Collisions with the container walls (ii) Collisions with other molecules Mean free path Effusion and gas leaks Molecular beams 10. Transport properties of gases Flux Diffusion Thermal conductivity Viscosity 2 1. Introduction - phases of matter There are four major phases of matter: solids, liquids, gases and plasmas. Starting from a solid at a temperature below its melting point, we can move through these phases by increasing the temperature. First, we overcome the bonds or intermolecular forces locking the atoms into the solid structure, and the solid melts. At higher temperatures we overcome virtually all of the intermolecular forces and the liquid vapourises to form a gas (depending on the ambient pressure and on the phase diagram of the substance, it is sometimes possible to go directly from the solid to the gas phase in a process known as sublimation).
    [Show full text]
  • Investigation of the Reflective Properties of a Left-Handed Metamaterial
    Wright State University CORE Scholar Browse all Theses and Dissertations Theses and Dissertations 2007 Investigation of the Reflective Properties of a Left-Handed Metamaterial Amanda Durham Wright State University Follow this and additional works at: https://corescholar.libraries.wright.edu/etd_all Part of the Physics Commons Repository Citation Durham, Amanda, "Investigation of the Reflective Properties of a Left-Handed Metamaterial" (2007). Browse all Theses and Dissertations. 92. https://corescholar.libraries.wright.edu/etd_all/92 This Thesis is brought to you for free and open access by the Theses and Dissertations at CORE Scholar. It has been accepted for inclusion in Browse all Theses and Dissertations by an authorized administrator of CORE Scholar. For more information, please contact [email protected]. INVESTIGATION OF THE REFLECTIVE PROPERTIES OF A LEFT-HANDED METAMATERIAL A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science By AMANDA DURHAM B.S., Embry-Riddle Aeronautical University, 2004 2007 Wright State University WRIGHT STATE UNIVERSITY SCHOOL OF GRADUATE STUDIES March 29, 2007 I HEREBY RECOMMEND THAT THE THESIS PREPARED UNDER MY SUPERVISION BY Amanda Durham ENTITLED Investigation of the Reflective Properties of a Left-handed Metamaterial BE ACCEPTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF Master of Science. _______________________ Lok Lew Yan Voon, Ph.D. Thesis Advisor _______________________ Lok Lew Yan Voon, Ph.D. Department Chair Committee on Final Examination ____________________________ Lok Lew Yan Voon, Ph.D. ____________________________ Gregory Kozlowski, Ph.D. ____________________________ Douglas Petkie, Ph.D. ____________________________ Joseph F. Thomas, Jr., Ph.D. Dean, School of Graduate Studies Abstract Durham, Amanda, M.S., Department of Physics, Wright State University, 2007.
    [Show full text]