INFICON RQCM - Quartz Crystal Microbalance Research System - Manual (Page 10)

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3.5 ADJUSTING CAPACITANCE CANCELLATION TRIMMER & SWITCH............................ 3-5
3.5.1 AS A GENERAL RULE........................................................................................................ 3-6
3.6 WORKING WITH VERY LOW Q CRYSTALS ........................................................................ 3-7
3.7 NORMAL OPERATION ............................................................................................................ 3-7
3.8 HOOKUP FOR ELECTROCHEMICAL EXPERIMENTS ........................................................ 3-7
3.9 OPERATION GUIDELINES...................................................................................................... 3-9
3.9.1 ALLOW THE RQCM TO WARM UP .................................................................................. 3-9
3.9.2 ISOLATE THE RQCM FROM TEMPERATURE CHANGE ............................................... 3-9
3.9.3 FOR OPERATION IN AIR................................................................................................... 3-9
3.9.3.1 Operate at or Near The Crystal’s “Turn-Around-Point”................................................ 3-10
3.9.3.2 Control The Temperature .............................................................................................. 3-10
3.9.3.3 Keep the Test Chamber Clean ....................................................................................... 3-10
3.9.3.4 Keep a Constant Gas Flow ............................................................................................ 3-10
3.9.4 FOR OPERATION IN LIQUIDS ....................................................................................... 3-10
3.9.4.1 Degas The Sample Liquid ............................................................................................. 3-10
3.9.4.2 Wait For Mechanical Disturbances To Stabilize ........................................................... 3-10
3.9.4.3 Wait For The Temperature To Stabilize ........................................................................ 3-10
3.9.4.4 Prepare Your Solutions Carefully.................................................................................. 3-11
3.9.4.5 Avoid Using A Stirrer.................................................................................................... 3-11
3.9.5 FOR OPERATION WITH THE FC-550 FLOW CELL ...................................................... 3-11
3.9.5.1 Avoid Excessive Differential Pressure .......................................................................... 3-11
3.9.5.2 Keep a Constant Line Pressure ...................................................................................... 3-11
3.9.5.3 Allow Ample Time For the Crystal To Come to Equilibrium....................................... 3-11
4 CRYSTALS, HOLDERS AND FLOW CELL ........................................................................ 4-1
4.1 1 INCH DIAMETER CRYSTALS .............................................................................................. 4-1
4.1.1 ELECTRODE CONFIGURATION ...................................................................................... 4-1
4.1.2 CRYSTAL PARAMETERS ................................................................................................... 4-2
4.1.3 CRYSTAL SURFACE FINISH ............................................................................................. 4-3
4.1.4 CRYSTAL ELECTRODE MATERIALS................................................................................ 4-3
4.1.5 CRYSTAL THICKNESS ....................................................................................................... 4-3
4.1.6 MASS SENSITIVITY ............................................................................................................ 4-3
4.1.7 STABILITY........................................................................................................................... 4-4
4.1.8 CRYSTAL LIFE EXPECTANCY .......................................................................................... 4-4
4.1.9 TEMPERATURE COEFFICIENT ....................................................................................... 4-5
4.2 CRYSTAL CARE AND HANDLING ........................................................................................ 4-7
4.2.1 CRYSTAL CLEANING......................................................................................................... 4-8
4.2.1.1 General Cleaning ............................................................................................................. 4-8
4.2.1.2 Organic (hydrocarbon contaminants) .............................................................................. 4-8
4.2.1.3 Biomaterials (lipids, proteins and similar biomolecules)................................................. 4-8
4.2.1.4 Lipid vesicles on SiO
2
surfaces........................................................................................ 4-8
4.2.1.5 Polystyrene removal ........................................................................................................ 4-8
4.2.1.6 Polymer Removal ............................................................................................................ 4-8
4.2.2 ELECTRODE SURFACE MODIFICATIONS ..................................................................... 4-9
4.2.2.1 SPIN COATING.............................................................................................................. 4-9
4.2.2.2 SELF-ASSEMBLED MONOLAYERS (SAM) .............................................................. 4-9
4.2.2.3 PHYSICAL VACUUM DEPOSITION (PVD)............................................................... 4-9
4.3 CRYSTAL HOLDERS.............................................................................................................. 4-10
4.3.1 HOW TO INSTALL A CRYSTAL IN A INFICON CRYSTAL HOLDER............................. 4-10
4.3.2 HOLDER CARE AND HANDLING................................................................................... 4-12
4.3.3 CONSIDERATIONS FOR BUILDING YOUR OWN HOLDER ........................................ 4-13
4.4 FLOW CELL............................................................................................................................. 4-13
5 THEORY OF OPERATION ................................................................................................... 5-1
5.1 SAUERBREY EQUATION........................................................................................................ 5-1
5.2 Z-MATCH EQUATION.............................................................................................................. 5-2