Atmospheric Pressure Plasma for Surface Modification

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Beverly, MA 01915-6106

Publishers at Scrivener Martin Scrivener (martin@scrivenerpublishing.com)

Phillip Carmical (pcarmical@scrivenerpublishing.com)

Atmospheric Pressure Plasma for Surface

Modification

Rory A. Wolf

Scrivener

WILEY

Copyright © 2013 by Scrivener Publishing LLC. All rights reserved.

Co-published by John Wiley & Sons, Inc. Hoboken, New Jersey, and Scrivener Publishing LLC, Salem, Massachusetts. Published simultaneously in Canada.

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Cover design by Russell Richardson

Library of Congress Cataloging-in-Publication Data:

ISBN 978-1-118-01623-7

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

I dedicate this book to my family, and particularly to my wife Julie who is my inspiration in everything I do and every choice I make.

I also dedicate the book to the team at Enercon Industries, without which this book would not have been possible.

Contents

Preface xi

1 Plasma - The Fourth State of Matter 1

1.1 Fundamentals of Plasmas 1 1.2 Thermal vs. Nonthermal Plasmas 6

1.2.1 Thermal Plasmas 7 1.2.2 Nonthermal Plasmas 14

1.3 Mechanisms for Surfaces Reactions 22

2 Plasmas for Surface Modification 27

2.1 Low-Pressure Plasmas 28 2.1.1 Surface Etching 30

2.2 Microwave Systems 31 2.3 Physical Vapor Deposition Systems 33

2.3.1 Physical Vapor Deposition Process 35 2.3.2 Ion Plating Process 38 2.3.3 Plasma-Enhanced Chemical Vapor

Deposition Process 40 2.4 Atmospheric Plasma Systems 42

2.4.1 Dielectric Barrier Discharge Systems 48 2.5 Atmospheric Plasma Precursor Deposition Systems 51

3 Atmospheric Plasma Surface Modification Effects 55

3.1 Surface Cleaning 56 3.2 Surface Etching 63

Vll

viii CONTENTS

3.2.1 Etching with Capacitively-Coupled Plasmas 67 3.2.2 Etching with Inductively-Coupled Plasmas 69

3.3 Surface Functionalization 70 3.4 Grafting and Surface Polymerization Effects 75

Characterization Methods of Atmospheric Plasma Surface Modifications 81

4.1 Surface Characterization Techniques 81 4.2 X-Ray Photoelectron Spectroscopy (XPS) 82

4.2.1 Design and Analytical Capabilities 83 4.2.2 Application Examples 85 4.2.3 Imaging of XPS 85 4.2.4 Element Mapping 86

4.3 Static Secondary Ion Mass Spectrometry by Time-of-Flight (ToF-SIMS) 86

4.4 Atomic Force Microscopy 89 4.4.1 Static Mode 91 4.4.2 Dynamic Mode 92

4.5 Scanning Electron Microscopy 94 4.6 Transition Electron Microscopy (TEM) 97 4.7 Visual Methodologies 98

4.7.1 Dyne Solutions 98 4.7.2 Contact Angle 103 4.7.3 Peel Force Adhesion 107

Atmospheric Plasma Modification of Roll-to-Roll Polymeric Surfaces 109

5.1 Material Classifications and Applications 110 5.2 Atmospheric Plasma Processing

Surface Effects 116 5.3 Assessments of Surface Modification Effects 118

Atmospheric Plasma Modification of Three-Dimensional Polymeric Surfaces 121

6.1 Material Classifications and Applications 125 6.2 Atmospheric Plasma Processing Surface Effects 129 6.3 Assessments of Surface Modification Effects 135

4

5

6

CONTENTS ix

7 Atmospheric Plasma Modification of Textile Surfaces 139

7.1 Material Classifications and Applications 141 7.2 Atmospheric Plasma Processing

Surface Effects 145 7.3 Assessments of Surface Modification Effects 151

8 Atmospheric Plasma Modification of Paper Surfaces 155

8.1 Material Classifications and Applications 157 8.2 Atmospheric Plasma Processing

Surface Effects 162 8.3 Assessments of Surface Modification Effects 164

9 Atmospheric Plasma Modification of Metal Surfaces 167

9.1 Material Classifications and Applications 168 9.2 Atmospheric Plasma Processing

Surface Effects 173 9.3 Assessments of Surface Modification Effects 178

10 Atmospheric Plasma Surface Antimicrobial Effects 181

10.1 Antimicrobial Surface Effects 183 10.2 Inactivation and Sterilization

Methods - Medical 186 10.3 Inactivation and Sterilization

Methods - Food 189

11 Economic and Ecological Considerations 195

11.1 Operating Cost Comparison of Atmospheric Plasma Systems 196

11.2 Environmental/Sustainable Advantages 201

12 Emerging and Future Atmospheric Plasma Applications 205

12.1 Solar and Other Alternative Energy Systems 205 12.2 Energy Storage Technologies 211 12.3 Aviation and Aerospace Applications 215 12.4 Electronic Device Fabrication 216

x CONTENTS

12.5 Air Purification Applications 220 12.6 Medical Engineering 221

13 Economic and Environmental Assessment 225

13.1 Goal and Scope 226 13.2 Functional Units 227 13.3 System Boundaries 230 13.4 Data Documentation 232 13.5 Lifecycle Interpretation 233

References 235 Index 243

Preface

This book is an outgrowth of practical commercial application work which I conducted with Enercon Industries Corporation and other industry partners for many years. During this time I have structured designs of experiment and performed laboratory trials to demonstrate the advantages of atmospheric pressure gas plasma discharges. The challenge in performing these activities and cajol-ing early adopters to comprehensively explore the full potential of these plasmas is the complexity of the process. The wealth of plasma phenomena discovered in so many diverse industrial and commercial fields makes it quite different from other atmospheric surface modification techniques such as corona discharge and gas flame. The physics and chemistries associated with the former are one-dimensional whereby the topographical and chemical binding effects are well known and, for the most part, predictable.

Although there are a number of books written which discuss cold plasmas, vacuum (low pressure) plasmas and their various applications, a book which addresses the practical application of atmospheric pressure plasmas for two-dimensional and three-dimensional surfaces appeared to be needed. This book will serve not only the industrial community but also university seniors and graduate students studying the physical sciences such as physics and chemistry and engineering sciences related to material, chemi-cal, and electrical disciplines. I am making the assumption that the reader has base knowledge of physics and chemistry. In addition, this book is also written to serve as a foundational and advanced reference tool for the manufacturing process engineer responsible for enhancing surface performance characteristics with techniques related to plasma, but also for the person in need of more in-depth knowledge of the atmospheric plasma application field.

XI

xii PREFACE

This book's focus and intent is to impart an understanding of the practical application of atmospheric pressure plasmas for the advancements of a wide range of current and emerging technolo-gies. Specifically, the reader will learn the mechanisms which con-trol and operate atmospheric plasma technologies and how these technologies can be leveraged to develop in-line continuous pro-cessing of a wide variety of substrates. The primary key feature of this book will be the introduction of practical experimental evi-dence of successful surface modifications by atmospheric plasma methods. It will also offer a handbook-based approach for lever-aging and optimizing atmospheric plasma technologies which are currently in commercial use. It also presents methods of generation, process diagnostics, and state-of-the-art applications for processing of a wide range of conductive and non-conductive materials. All of the chapters focus on cold atmospheric pressure plasmas relative to incumbent regimes. The principles of the various methods to create and sustain an atmospheric pressure plasma are presented, along with reactions that can possibly occur between these plasmas and a solid surface with which it is in contact. The different types and designs of plasma reactors are presented, as well as their features and benefits. A selection of applications of cold atmospheric pres-sure plasmas for processing specific industry segment surfaces is also profiled.

By writing the book, it is my hope that a new class of atmospheric plasma discoverers will emerge. Providing the theoretical frame-work of plasma physics as a basis for understanding the origins and principles of commercial designs was, to me, the most appropriate approach to progressing refinements and new developments in the field. The visual impression of an atmospheric pressure plasma dis-charges is only that of radiation from embedded atoms. Therefore, there was a need to document evidence of specific atmospheric plasma properties, such as density and temperature, to form the foundation for more effective surface modifications using these plasmas.

July 17,2012 Menomonee Falls, Wisconsin