SYNTHESIS AND CHARACTERIZATION OF BORON COMPOSITE NANOPARTICLES FOR WEAR AND FRICTION REDUCTION A Thesis Submitted to the Graduate School of Engineering and Sciences of ø]PLU,QVWLWXWHRI7HFKQRORJ\ in Partial Fulfillments of the Requirements for the Degree of MASTER OF SCIENCE in Chemical Engineering by Esin GÖKMEN July 2019 ø=0ø5 We approve the thesis of Esin GÖKMEN Examining Committee Members: Prof. Dr. Mehmet POLAT Department of Chemical Engineering, İzmir Institute of Technology Prof. Dr. Ekrem ÖZDEMİR Department of Chemical Engineering, İzmir Institute of Technology Prof. Dr. Mustafa DEMİRCİOĞLU Department of Chemical Engineering, Ege University 12 July 2019 Prof. Dr. Mehmet POLAT Supervisor, Department of Chemical Engineering İzmir Institute of Technology ____________________________ ____________________________ Prof. Dr. Erol ŞEKER Prof. Dr. Aysun SOFUOĞLU Head of the Department of Chemical Dean of the Graduate School of Engineering Engineering and Sciences ACKNOWLEDGMENTS Foremost, I would like to express my very great appreciation to my advisor Prof. Dr. Mehmet POLAT for his valuable and constructive suggestions, continuous support during the planning and development of this research work. I could not have imagined having better mentor for my study. I would like to offer my special thanks to my co-advisor Prof. Dr. Hürriyet POLAT. Her guidance helped me in all time of research and writing of this thesis. Her willingness to give his time so generously has been very much appreciated. I wish to thank to Prof. Dr. Mustafa DEMø5&ø2ö/8 and Prof. Dr. Ekrem g='(0øR for accepting to be part of the Thesis Defense Jury. My special thanks are extended to the R&D staff of Opet Fuchs for their valuable support. I am thankful to my lab-mate Elif Suna SOP for their endless supports and contributions during my experiments. I feel very lucky to know her and to be her friend. I would like to express my gratitude to my dear friends $\úH0(7(&$1$\GÕQ &ø+$12ö/8 0HUYH'(0ø5.857 Ece Zeynep TÜZÜN, *L]HP&ø+$12ö/8 and gQGHU7(.ø1$/3 for their patience and support during writing of my thesis. Finally, and the most important, I am really indebted to my family, my sister Emel DURAN and my dream partner 8ODú$7ø./(5 for giving me chance to improve myself, and also their unconditional love, endless courage and precious support. ABSTRACT SYNTHESIS AND CHARACTERIZATION OF BORON COMPOSITE NANOPARTICLES FOR WEAR AND FRICTION REDUCTION Since most of the conventional lubricants reach their performance limits, new antiwear and extreme pressure (EP) additives are designed so that lubricants can minimize friction and wear when used in high temperature and pressure conditions. There is growing interest in the use of nanoparticles as an additive in lubricants. Due to its outstanding chemical properties, boron is frequently involved in the design of nanoparticles. Especially borate derivatives and hexagonal boron nitride (h-BN) have already taken their places in many lubricant formulations. The aim of this study was the production of silica-boron composite nanoparticles that can replace the phosphate-derived additives used in lubricant formulations and to provide the extreme pressure, antiwear and friction-regulating properties at the same time. For this purpose, the Stöber method that is used for silica production was modified to produce Si/Na-Borate nanoparticles. It was found that the synthesis of composite nanoparticles in desired size distribution and morphology as well as composite structures composed of Si and Na-Borate, was possible changing the amounts of ingredients and modes of addition. It was observed that the morphology and the chemical structure of these particles depend on the amount of Na-Borate (1, 3, and 5% w/w) and the addition type of Na-Borate (Direct, 500 PL/min, 5PL/min). Then composite nanoparticles were characterized using SEM, FTIR and ICP-MS and some tests were conducted to examine the structure of particles. The tribological performance of these particles tested using Four Ball Test method have shown that there is a significant improvement in the presence of these particles. iv ÖZET $ù,10$9(6h57h10(<ø$=$/70$.ødø1%25.2032=ø7 1$127$1(/(5ø16(17(=ø9(.$5$.7(5ø=$6<218 .RQYDQVL\RQHO RODUDN NXOODQÕODQ \D÷OD\ÕFÕODUÕQ oR÷X SHUIRUPDQV VÕQÕUODUÕQD XODúWÕ÷Õ LoLQ \D÷OD\ÕFÕODUÕQ \NVHN VÕFDNOÕN YH EDVÕQo NRúXOODUÕQGD NXOODQÕOGÕ÷ÕQGD sürtünmH YH DúÕQPD\Õ PLQLPL]H HGHELOPHOHUL DPDFÕ\OD \HQL DúÕQPD |QOH\LFL (AW: Antiwear YH DúÕUÕ EDsÕQo (3 ([WUHPH 3UHVVXUH NDWNÕODUÕ WDVDUODQPDNWDGÕU 1DQRWDQHOHULQ \D÷OD\ÕFÕODUGD NDWNÕ RODUDN NXOODQÕPÕ NRQXVXQGD JLGHUHN DUWDQ ELU LOJL YDUGÕUgQHoÕNDQNLP\asal özellikleri nedeniyle bor, nanotanelerin WDVDUÕPÕQGDVÕNOÕNOD NXOODQÕOPDNWDGÕU. Özellikle borat türevleri ve hegzagonal bor nitrür (h-BN) KDOLKD]ÕUGa ELUoRN\D÷OD\ÕFÕIRUPOQGH\HULQLDOPÕúWÕU <D÷OD\ÕFÕIRUPODV\RQODUÕQGDNXOODQÕODQIRVIDWWUHYOLNDWNÕODUÕ ikame edebilecek, DúÕUÕEDVÕQoNRúXOODUÕQGDNXOODQÕODELOHFHN DúÕQPDYHVUWQPHönleyici |]HOOLNOHULQLD\QÕ DQGDVD÷OD\DELOHFHNERUOXQDQRWDQHOHULQUHWLPLYH\HQLQHVLO\D÷OD\ÕFÕODUGDNXOODQÕOPDVÕ bu tezin en önemli motivasyonudur Bu amaçla, silika nanotanelerin üretilmesinde NXOODQÕODQ6W|EHU\|QWHPLPRGLIL\HHGLOHUHN6L1D-Borate QDQRWDQHOHULVHQWH]OHQPLúWLU .RPSR]LWQDQRWDQHOHULQLVWHQLOHQER\XWGD÷ÕOÕPÕQGDYHPRUIRORMLVLQGHVHQWH]OHQPHVLQLQ ELOHúHQOHULQ PLNWDUODUÕQÕQ YH VLVWHPH LODYH HGLOPH úHNOLQLQ GH÷LúWLULOPHVL ile mümkün ROGX÷XJ|UOPúWU.RPSR]LWQDQRWDQHOHULQPRUIRORMLVLYHNLP\DVDO\DSÕVÕQÕQVRG\XP borat (Na-Borat) çözeltisinin konsantrasyonu (kütlece % 1, 3 ve 5) ve sisteme eklenme úHNOLLOH (bir defada, 500 L /dk., 5 L /dk) GR÷UXGDQLOLúNLOLROGX÷XJ|]OHPOHQPLúWLU Sentezlenen kompozit nanotaneler SEM, FTIR ve ICP-06 NXOODQÕODUDN NDUDNWHUL]H HGLOPLúYHWDQHOHULQ\DSÕVÕQÕLQFHOHPHNLoLQLODYHWHVtOHUGHJHUoHNOHúWLULOPLúWLU $\UÕFDVHQWH]OHQHQQDQRWDQHOHULQtribolojik performansÕDört BilyaTest yöntemi NXOODQÕODUDNWHVWHGLOPLúWLUYHWDQHOHULQ\D÷OD\ÕFÕODUÕQWULERORMLN|]HOOLNOHULQLJHOLúWLUGL÷L J|UOPúWU v TABLE OF CONTENTS ACKNOWLEDGMENTS ................................................................................... iii ABSTRACT......................................................................................................... iv ÖZET ............................................................................................................ v TABLE OF CONTENTS..................................................................................... vi LIST OF FIGURES ............................................................................................. ix LIST OF TABLES ............................................................................................... xi LIST OF ABBREVIATIONS ............................................................................. xii CHAPTER 1. INTRODUCTION ......................................................................... 1 1.1. Statement of the Problem ..................................................................... 1 1.2. State of the Art ..................................................................................... 2 1.3. Scope of the Study ................................................................................ 4 CHAPTER 2. BACKGROUND AND LITERATURE REVIEW ....................... 5 2.1. Background Information ....................................................................... 5 2.1.1. Friction ....................................................................................... 5 2.1.2. Wear ........................................................................................... 8 2.1.3. Fundamentals of Lubrication and Lubricants ............................. 9 2.1.4. Lubrication Regimes and Stribeck Diagram ............................ 10 2.1.5. Lubricants ................................................................................. 12 2.1.6. Lubricant Additives .................................................................. 13 2.1.7 Antiwear (AW) and Extreme Pressure (EP) Additives ............. 18 2.2. Literature Review ............................................................................... 20 2.2.1 Conventional AW and EP Additives ......................................... 21 2.2.2. Novel AW and EP Additives-Nanoparticles in Lubricants ...... 24 2.2.3. Boron Compounds as AW and EP Additives ........................... 28 vi CHAPTER 3. MATERIALS AND METHODS ................................................ 36 3.1. Materials ............................................................................................. 36 3.2. Methods .............................................................................................. 36 3.2.1. Synthesis and Characterization of Composite (Si/Na-Borate) Nanoparticles ........................................................................... 37 3.2.1.1. Effect of Na-Borate Concentration on Synthesis of Composite (Si/Na-Borate) Nanoparticles ................... 40 3.2.1.2. Effect of TEOS amount on Synthesis of Composite (Si/Na-Borate) Nanoparticles ..................................... 40 3.2.1.3. Effect of Mode of Na-Borate Addition on Synthesis of Composite (Si/Na-Borate) Nanoparticles .............. 41 3.2.1.4. Understanding the Structure of the Composite Nanoparticles .............................................................. 41 3.2.1.5. Material Balance ......................................................... 42 3.2.2. Tribological Performance of Composite Nanoparticles ........... 42 3.2.2.1 Dispersion of Composite Nanoparticles ...................... 42 3.2.2.2 Four Ball Extreme Pressure Test to define the Load- Wear Index