Masaaki Okubo Nonthermal Plasma Surface Modification of Materials Nonthermal Plasma Surface Modification of Materials Masaaki Okubo Nonthermal Plasma Surface Modification of Materials Masaaki Okubo Department of Mechanical Engineering Graduate School of Engineering Osaka Metropolitan University Sakai, Japan ISBN 978-981-99-4505-4 ISBN 978-981-99-4506-1 (eBook) https://doi.1007/978-981-99-4506-1 © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc.
in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
This Springer imprint is published by the registered company Springer Nature Singapore Pte Ltd. The registered company address is: 152 Beach Road, #21-01/04 Gateway East, Singapore 189721, Singapore Paper in this product is recyclable. Preface This book describes various types of nonthermal plasma surface modification tech- nologies for materials at varying atmospheric-pressure and low-temperature condi- tions, and it is among the first to address these topics. Furthermore, this book aims to bridge the gap between fundamental and technical aspects with respect to industrial applications in material and plasma engineering.
The main objective of this book is to provide readers with an easy-to-understand resource that outlines the foundations and application potential of nonthermal plasma surface modifications. In recent years, the surface modification of materials has gained considerable attention in the field of advanced manufacturing. The technology for the surface modification of materials can be classified into two groups: (1) reduced-pressure plasma treatment and (2) atmospheric-pressure plasma treatment. The latter has many advantages, such as compatibility with industry apparatus, because a reduced- pressure environment can be avoided.
Compared to other treatments, nonthermal plasma treatment offers the possibility of a strong and effective modification. Typically, surface treatment using fluoroplastics, such as perfluoroalkoxy alkane (PFA), polytetrafluoroethylene (PTFE; Teflon), and polychlorotrifluoroethylene (PCTFE), is considered an original, unique, and successful feature. Fluoroplastics have excellent characteristics such as chemical resistance, electrical insulation, heat resistance, flame resistance, and high gas barrier properties, and therefore, they are widely used. However, owing to their high hydrophobicity, they cannot be easily bonded to other materials without losing these characteristics.
My group has solved this problem using our innovative atmospheric-pressure plasma hybrid processing technology and achieved high adhesiveness for the first time. Our technology is expected to be widely applied in the future. Nonthermal plasma surface modification is an interdisciplinary field that is physic- ochemical in nature and has applications in mechanical, electrical, and chemical engineering. Given that practitioners in these fields hail from diverse backgrounds, I strove to devise a technology that is sufficiently self-contained to be accessible to engineers, scientists, and students from many fields.
v vi Preface The contents of the book are summarized as follows: Chapter 1 defines plasma and outlines the fundamentals of nonthermal plasma technologies. A method to generate atmospheric-pressure nonthermal plasma is described. Chapter 2 addresses the fundamentals of surface treatment technolo- gies and characterization. The principle of plasma graft polymerization, evaluation method of surface treatment effects, and apparatus used for surface modification characterization are described.
Chapter 3 describes the hydrophilic treatment of polymer surfaces and its applications. The principle and methods of plasma treat- ment and plasma graft polymerization treatment are described. Furthermore, the application of PTFE/plastic to millimeter-wave devices, development of organic light emitting diode (OLED) elements, and improved adhesion of fluoropolymer film to butyl rubber for biomedical applications are expounded. Chapter 4 describes the hydrophilic treatment technology for textiles, filters, and glass and its appli- cations.
The surface treatment of fibers, apparel, and deodorization technology using these treated materials are described. Chapter 5 covers the hydrophobic treat- ment of polymer surfaces. Diamond-like carbon (DLC) plasma surface treatment hydrophobic technology, catalyst surface treatment, and trends in other surface treat- ments with plasma are explained. Chapter 6 describes the hydrophobic treatment of plastic, glass, and metal surfaces and its applications.
The principles of plasma cleaning and surface activation are explained. Several examples of the implementa- tion of hydrophobicity by plasma cleaning and activation are described, and plasma corrosion-resistant chemical hybrid treatments are explained. Chapter 7 describes plasma and electron-beam technologies used for surface treatment applications. The principles of electron-beam technology for surface treatment and plasma jet steril- ization of surfaces are described, and respective examples are provided.
Chapter 8 describes measurement technology for functional groups generated by plasma treat- ment. The characterization and analysis of functional groups can be used to eval- uate the effect of surface modification. Suitable technologies for the analysis of functional groups and chemical species formed by plasma treatment are described. Concluding remarks summarize the contents of this book and outline future prospects.
The topics treated in this book are presented as self-contained descriptions derived from literature, and Appendix presents supporting information on Sakai city where this book was written, along with the principles of measurement apparatus for surface treatment. I hope technologists in industries, academic university professors, and graduate students in engineering alike find this book useful. The unique elements of this book can be expressed as follows: 1. Covers: Principle, apparatus, methods, and industry application examples of nonthermal plasma surface modification technologies.
Explains: Principle and methods of nonthermal plasma surface modification technologies, in particular, knowledge on the generation of atmospheric-pressure plasma is provided. Demonstrates: Successful industry application technologies for atmospheric- pressure plasma surface treatment. Introduces: Principle and methods of nonthermal plasma surface modification technologies for beginner engineers and graduate students. Readers: I strongly recommend this book for all those who work or intend to work on the adhesion of poorly adhesive materials.
Our research group has a history of more than 20 years of performing research projects on the surface modification for many companies toward the development of new machines. These projects have provided us with a wide range of exciting experiences. We aim to share our fascination with this technology through this book to enable scientists and engineers to engage in it successfully. I believe that our research work should be documented and it is vital that these technologies are conveyed to the future generations.
Most of these projects were conducted at Osaka Prefecture University (currently Osaka Metropolitan University) in Sakai city, Osaka Prefecture, Japan. Sakai city has prospered in ocean trade for centuries. In the sixteenth century, it was called “Oriental Venice” or “Saccai” to Europeans, and it has been a prosperous international trade port and home to many industries. At present, Sakai city is an important industrial city in Japan with a large factory zone in the coastal area.
Sakai has a long tradition of metal manufacturing. I am delighted to publish this book on the plasma surface treatment technology from Osaka Metropolitan University, which is located in this traditional Japanese city. This book covers recent developments in nonthermal technologies and their funda- mental aspects. I have also described selected applications of surface modification technologies.
While some of these technologies have reached the commercial stage, others are still in early development. This book provides technical details and test results rooted in fundamentals of plasma engineering. The author first wrote each chapter separately based on materials that have been published previously as scientific papers, reviews, and book chapters, and then, the contents were knit together to maintain comprehensive unity. I am grateful to many individuals who assisted during the preparation of this book.
Ayako Yoden for her meticulous typing of the handwritten manuscripts. It has also been a pleasure to work with the editor of this book Mr. Smith Ahram Chae and Mr. Rajesh Manohar, Project Coordinator—Total Service.
Collaborations with many colleagues over a number of years have been very enriching and enjoyable. I have discussed the future prospects of various plasma treatment systems with Dr. Tomoyuki Kuroki and Dr. Haruhiko Yamasaki of Osaka Metropolitan University, Dr.
Toshiaki Yamamoto and Dr. Hidekatsu Fujishima of Osaka Prefecture Univer- sity, Dr. Keiichiro Yoshida of Osaka Institute of Technology, Dr. Takuya Kuwahara of Nippon Institute of Technology, and Dr.
Hashira Yamamoto of Nihon Yamamura Glass Co. Research studies performed with many students for over 20 years at Osaka Prefecture University and Osaka Metropolitan University have been enriching and enjoyable, and most of these are credited in this book through citations of their viii Preface published work. I have truly enjoyed studying and performing experiments on plasma treatments. I hope that this book proves beneficial not only to material engineers and students but also to professionals in other fields such as electrical, mechanical, chem- ical, and environmental engineering who wish to gain essential knowledge on the emerging plasma surface modification technologies.
Sakai, Japan Masaaki Okubo Contents 1 Fundamentals of Nonthermal Plasma Technologies .2 Generation of Atmospheric-Pressure Nonthermal Plasmas .3 What Are Plasmas? .4 Types of Plasmas .5 Pulse Corona Plasmas .6 Dielectric Barrier Discharge-Induced Plasmas .7 High-Frequency Plasmas .1 Surface Discharge Plasma .2 Radio-Frequency Plasma .3 Microwave-Generated Plasma. 16 2 Fundamentals of Surface Treatment Technologies and Characterization .2 Mechanism of Surface Modification .3 Plasma Graft Polymerization .4 Apparatus for Surface Treatment .5 Surface Characterization Methods .1 Contact Angle Measurement .2 Evaluating Adhesive Properties by Peeling Test .3 Result of Surface Analysis by ESCA (XPS) .4 Result of FTIR Analysis .5 Result of SEM Analysis. 34 ix x Contents 3 Hydrophilic Treatment for Polymer Surfaces and Its Applications .2 Plasma Treatment and Plasma Graft Polymerization Treatment .2 Examples of Plasma Treatment Electrodes .3 Principle and Example of Hydrophilic Plasma Treatment .4 Plasma Surface Treatment and Plasma Graft Polymerization Surface Treatment Mechanism .5 Structure of the Three Electrodes with Different Potentials .6 Principle of Atmospheric-Pressure Plasma Graft Polymerization and Adhesion Improvement Mechanism .3 Atmospheric-Pressure Plasma Graft Polymerization Treatment .1 Atmospheric-Pressure Plasma Graft Polymerization Apparatus .2 Surface Treatment Evaluation for PTFE Metal Plating .3 XPS Analysis Results .4 Applicability of PTFE/Plastics in Millimeter-Wave Devices .1 Plastic Properties: Dielectric Constant, Dielectric Loss Tangent, and Hydrophobicity .2 Small High-Performance Millimeter-Wave Band Antennas .3 Applicability to High-Frequency Coaxial Cables .4 Method of Copper Plating on PTFE and Results .5 Surface Treatment of Dielectric Cable .6 Method of Nickel Plating on PTFE and Results .7 Microfabrication of Nickel Plating on PTFE .8 Applicability to Radome .9 Plasma Hybrid Surface Treatment of Fiber-Reinforced Composite Materials .5 Development of OLEDs on PCTFE .1 Flexible OLED Element .2 Peeling Strength for PCTFE .3 XPS Analysis Results .4 SEM Observation Results .5 Prototype Fabrication Procedure for OLED Device on PCTFE .6 Improved Adhesion of Fluoroplastic Film to Butyl Rubber .1 Application Example: Prefilled Syringe .2 Butyl Rubber and PTFE Film Composite Material .3 Peeling Test of Fluoroplastic Film–Butyl Rubber Composite .4 Peeling Strength of the Composite Material .5 Molecular-Level Adhesion Mechanism Between Rubber and PTFE. 92 4 Hydrophilic Treatment Technology for Textiles, Filters, and Glass and Its Applications .2 Surface Treatment of Textiles and Apparels .1 Principle of Functional Surface Treatment .2 Experimental Apparatus and Methods .3 Experimental Results and Discussion .3 Deodorization Technology Using Low-Temperature Nonthermal Plasma .1 Plasma Deodorization Technology .2 Methods for Producing and Measuring Performance of Functional Filters .3 Experimental Results and Explanation .4 Increased Glass Surface Hydrophilicity by Nonthermal Plasma Treatment .1 Definition of Contact Angle .