We've all been there, walking along minding our own business when splat! That dreaded step into the abyss. Gum or worse DOG POOP! Now everything stops.
Your number one priority now is to remove the offending stuff from the bottom of your shoe. You limp around looking for a spot to sit down, remove your shoe, find a stick or something, and pick out that stuff. If you're lucky you're wearing smooth bottom shoes and you can quickly wipe off what shouldn't be on the ground in the first place. If not, you're in for 10 minutes of picking and swearing.
For laboratory analysts and field engineers that sticky gum or poop is equivalent to all manor of compounds that want to "stick" to the analytical flowpath. GC systems, HPLC, sampling trains, probes, heat trace tubing, sample cylinders, flare and continuous emission monitors all suffer from "gum shoe syndrome"; we call it adsorption, but the idea is the same. Stuff you want or sometimes don't want gets stuck to the flowpath surface and won't come off. But rather than just a few minutes of swearing, the analyst may be faced with days of troubleshooting to isolate the source of the adsorption.
The consequences of gum on shoe is minimal, but in the analytical world, adsorption can mean lost time, lousy productivity, costly retesting, misleading results, poor yield, or regulatory compliance problems. In short, adsorption or sticky compounds can cost real money. A 1 hour delay in operations can cost an 800,000 tpy ethylene plant $50,000. A 250,000 tpy LDPE unit will cost operations $36,000 for a 1 hour upset while an EBSM styrene plant will cost $33,000.
Think bio/pharma has fewer, less costly issues with sticking compounds? Who wants to put someone through the trauma of telling them they have cancer, only to later realize protein sticking & carryover resulted in a false positive test?
Refineries don't have it any easier. Sulfur compounds sticking to stainless steel flowpaths can lead to extreme delays in results. A refinery can be out of compliance or ship bad product for 90 minutes or more before the analyst realizes there's an issue.
The Culprits
Sulfur compounds, carbon, proteins and others can all stick to surfaces. Examples are:
| H2S |
Ammonia |
| SOx |
Bio proteins |
| COS |
NOx |
Sticky surfaces can be an issue throughout industry from analytical, bio analytical, to semiconductor manufacturing, to automotive and aerospace. The factors that cause surface sticking can range from carbon coking, non-specific protein binding, adsorption or surface energy issues. Changing the condition of the surface is key to preventing your analyte or critical fluid from binding to the flowpath surface. That's where inert coatings add value.
The Solution to Sticky Surfaces
Adhesion, adsorption, chemisorption, physisorption of compounds to stainless steel, glass, or alloy surfaces can lead to trouble, that's why inert coatings exist. To be that ideal flat soled shoe that nothing sticks to; only better, about 1000 times better in fact. SilcoTek coatings act as a barrier, preventing critical fluid interaction with reactive surfaces. Inert coatings don't react with or degrade the analyte, allowing detection levels down to single digit part-per-billion compared to 1 or 2 percent accuracy for an equivalent uncoated surface. No sticking!
Dealing with sticky compounds head on by lining the flowpath with Dursan® or SilcoNert® is the best way to avoid that gum-on-shoe feeling.
Removing the Sticky Stuff
If you've got something in your flowpath that is sticking, adsorbing and desorbing to the surface, here are a few tips on how to remove bad actors from the flowpath.
Click on Charlie Bubblehead here and go to our recommendations for cleaning stainless steel surfaces.
