How do you normally clean your SiO2 substrates before your experiments?
I suggest a dip in piranha solution (10 min), so everything organic is removed. Then rinse the substrate in deionized water and blow it dry with compressed nitrogren. If you do not have access to H2O2 and H2SO4, you can try an ultrasonic bath (acetone) with subsequent isopropanol rinse and blow-drying. It will not yield the same results, though. A gentle oxygen plasma cleaning step might also work well, if you have a reactive ion etching chamber available.
Actually, I am also doind second method, acethon in ultrasonic bath and isopropanol.
But I am not sure if it is enough for my particles because after spin coating of my particles, i realize sometimes i do not have particle on the substrate,
I do not know what is going on between my particles and wafer, i dont know surface properties, tough.
Thanks a lot for the comment..
you can find different cleaning methods for glass which is like SiO2 and their comparison in the paper below.
http://www.sciencedirect.com/science/article/pii/S0956566399000433
Also, plasma oxidation is another way to clean the surface of glass,silica, PDMS, etc.
Cleaning routine:
1) 5 mins sonication in 1% (v/v) Hellmanex solution
2) 2x dump rinse in hot water
3) 5 mins sonication in IPA
4) 2x dump rinse in deionised water
5) N2 blow dry
It depends on what you do with this oxide. It depends if you have only oxide on your wafer (no metal, or other pattern ?). Is this SiO2 for electrical insulation, or simply a sacrificial oxide, or a native oxide. It depends also on its thickness. If you have 4nm of a super high quality SiO2 (for gate oxide), or do you have 2microns thick SiO2 made by sputtering. Do you want to keep the integrity of your oxide ?
Cleaning examples : 1) acetone/ethanol/DI water 2)plasma O2, 3) H2SO4/H2O2, ...
To clean glass, silicon, quartz wafers you can follow the preparation here
DOI: 10.1016/j.cplett.2018.07.012
In brief. Clean 1st with acetone in USB for 30min, 2nd with Isopropanol in USB for 30 min. Then use saturated Isopropanol solution of KOH (20mg in 100ml). Immerse wafers into and keep at least 12H. After, using the flow of hot water clean wafers until the water will stop bubling. N2 flow drying. Finally 1% of APTES in dry methanol for 2H. Then 2x in methanol in ultrasonic bath, drying with N2 . It works pretty well with one "no". Very often when preparing set of 10 wafers sample 2 among them have aggregated nanoparticles....Why?! I dont know. I will try pihrana solution today to increase the number of OH groups on the surface. Have and idea that low number of OH surface groups doesnt allow to bind APTES with 3 legs ...
But all the time those who using the APTES should keep in mind that even humidity in the lab influences on the quality of APTES coating.
The second important point is following. As soon as you buy new bottle of APTES solution spread in in 5-10ml glasses under N2 conditions(better in Glowbox).
If you have no nanoparticles on the surface, which was precoated with APTES, try to verify pH of the nanoparticle solution. It should be slightly acidic. With this you can charge amines on the surface to induce nanoparticles attachment (obviously if nanoparticles are negatively charged, for instance Turkevich nanoparticles)
Ultrasonication in Acetone and then IPA for 10 mins each. Dry with N2 and use UV Ozone cleaning for 5-10 mins.
it depends on what you want to do. there are a lot of methods. please check the link. you can use some references to find out.
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=Mechanical+behavior+of+3D+GFRP+composite+with+pure+and+treated+shear+thickening+fluid+matrix+subject+to+quasi-static+puncture+and+shear+impact+loading&btnG=
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