Presentation on theme: "Gary Barone, Marty Higgins, David Smith SilcoTek Corporation"— Presentation transcript:
1Gary Barone, Marty Higgins, David Smith SilcoTek Corporation The Characterization of Novel Carboxysilane Depositions on Stainless Steel Substrates for Inertness, Wear Resistance, and Corrosion Resistance ApplicationsGary Barone, Marty Higgins, David SmithSilcoTek Corporation
2Overview Use of Coatings Selecting Coatings Conclusion Coating Materials/PropertiesDurabilityCorrosion TestingMoisture ResistanceChemical InertnessConclusionEnter speaker notes here.
3Using Coatings Most analytical pathways are stainless steel Great structurallyGood corrosion resistancePoor chemical properties for analytical chemistsCoatings used to improve material properties.Industries are demanding harsher services for silicon coatings (like SilcoNert® 2000 (Sulfinert).Carboxysilane coatings (Dursan®) more robust.
4Factors Contributing to Poor Sampling Reliability Durability/WearCorrosionMoistureDesignChemical & Material Compatibility/InertnessInstrument CompatibilityInstallation
5Selecting Coatings Silicon (SilcoNert® 2000) Fluoropolymers Very inert Great adhesionNo carryoverGood corrosion resistanceLimited pH rangeSusceptible to steam cleaningPoor wear resistanceGood to 450°CFluoropolymersVery inertVery corrosion resistantBroad pH applicabilityPoor adhesionPoor wear resistanceGood to 260°C
6New Coating Carboxysilane (Dursan®) Good inertness Great adhesion No carryoverGood corrosion resistanceBroad pH applicabilitySteam cleaning, no problemGood wear resistanceTested to 450°CStill accumulating application data
7Coating/Material Properties PropertySilicon(SilcoNert 2000)CarboxysilaneDursanPTFE,PFAMax Temperature450ºC260ºCMin Temperature-196ºC-100ºC-240ºCLow pH limitHigh pH limit714Thickness0.12um to 0.5um0.5um to 1.0um25umAdhesionVery GoodPoorWear resistance90% of Stainless2 times316 Stainless10% of SS (est.)Moisture contact72-90°°125°Inertness vs. SSExcellentGood
8Improving wear resistance & Durability Equipment and sample conditions can damage surfaces and increase activity.Valve cycling/purging cause delaminationParticulate in sample streamsAbrasive cleaningExisting coatingsProne to wearEasily damagedResult: Adsorption & loss of sample
9Wear and Friction Data Pin on Disc: ASTM G133 Base substrate is mirror-finish SS 316Avg. Coeff. FrictionWear Rate(x10-5mm3/Nm)Uncoated SS0.58913.810Carboxysilane (Dursan)0.3786.129Silicon (SilcoNert 2000)0.714.00Load2.0 NDuration20 minSpeed80 rpmRadius3mmRevolutions1,554Ball Diameter6mmBall MaterialSS 440Courtesy of Nanovea Inc.
10Pull Strength Measurements Paints delaminated from the stainless steel
11Pull Strength Measurements Dursan more “slippery” difficult to bond adhesive. Adhesive bond failed before coating. Demonstrating reduced friction characteristics.
12Challenge of Corrosion Samples can contain corrosives that quickly attack stainlessHydrochloric acid (HCl)Sulfuric acid (H2SO4)SaltwaterPhysical loss of equipment due to corrosionMaintenanceReplacement cyclesCorrosion increases surface activity and particulatesSilicon coatings susceptible to caustics
13Acid Corrosion Resistance ASTM G31 Guidelines: 6M HCl; 24hr; 23ºC316L SSSiliconCarboxysilaneMPY181.984.320.44Improvement Factor over 316L stainless---42411Dursan coatedPhoto after 19hrexposureSilcolloy coated
15Exposure to Caustic Base 1M KOH; 24hr; 22ºCASTM G31316L SSSiliconCarboxysilaneMPY3.400.01Improvement FactorOver SiliconInfiniteDissolution261
16Challenges of Moisture Benefits of coating that help release water fasterComponents less susceptible to corrosionFaster cycle timesIncreased accuracyEliminate moisture/sample interaction
17Impact of MoisturePresence of moisture in sampling system reduced H2S response by 22%: 50ppm sample
18Measuring Hydrophobicity DI Water304 SSSilcoNert 2000DursanPTFEAdvancing36.087.3105.5125.4Receding5.351.585.384Kruss K100 TensiometerTesting on304 SS¼” OD tubingDI Water Contact Angle Illustrations (advancing) on flat surfaces:304 SSSilcoNert 2000Dursan
19Chemical InertnessStainless Steel:Adsorbs sulfur compoundsCauses loss of mercuryDemonstrates poor transportability (tailing) of polar organics such as alcoholsAdsorbs ammoniaNeed coating that is chemically inert for analytical systems
20Total Sulfur Recovery 36ppb & 25ppm, 300cc cylinder SilcoNert: 36ppb 99%+ recoverySS 80% loss in 1 day
21Mercury 50 Day StabilityCourtesy of Spectra Gases Inc.
22Ammonia Adsorption 100PPV, 500sccm, 1.8m tubing, min Measured PTR-MS signals of ammonia (m17). At t=10min the gas stream was switched in a waythat it passed additionally the different 1.8m long lines. The PFA line seems to be best for Ammonia, whilethe steel line completely adsorbs the 100ppbv of Ammonia in the sample gas for hours. All lines were 1.8 m,not heated (30°C), sample gas flow was 500 sccm (std. ml/min) of 100 ppb of ammonia in N Courtesy of IONIMED Analytik
23Selecting Coatings Factor Durability Poor wear resistance FluoropolymersWeightSilicon(SilcoNert )Carboxysilane(Dursan)DurabilityPoor wear resistanceFair wear resistanceGood wearresistanceCorrosionExcellentGoodMoistureInertnessExcellent/ no carryoverChemical / Material CompatibilityPoor adhesion/ Broad pH rangeExcellent adhesionInstrument CompatibilityInstallation260c max450c max
24ConclusionAnalytical and Process industries demanding increased performance from coatingCoating selection dictated by applicationCorrosion resistanceMoisture resistanceInertnessWearBroad spectrum environments and applications may involve a tradeoff in performance.In field applications, carboxysilane coatings (Dursan) may be the best overall performer.