[Jman]

I usually clean my LCD monitors that have some faint dust & finger prints with isopropyl alcohol mixed with demineralized water at around 30% concentration. I normally use the wipe on, wipe off approach with clean microfiber cloths for a perfect streak free finish leaving residue.

But I have noticed if the surface of the screen is luke warm - pretty warm like from after using my Monitor for a while, that I don't even need to do the wipe off stage for a perfect streak free finish.
But if the surface is cold without the wipe off stage I will get a few streaks over the place.

So why is this & what does the temperature have to do with giving a perfect finish? As if it evaporates on it's own won't that simple leave behind streaks? And what would you think are these streaks? Since all there is just a bit of dust & occasional finger prints on the surface.

[Enthalpy]

I wouldn't use any amount of water on electronic devices. They are plain incompatible.

Against dust, a brush (for paint) is just perfect.

Against finger prints, a dry cloth is efficient. You might add some alcohol if really necessary, but don't put water.

Against more sticky dirt, like ball pen traces, use an eraser.

[Jman]

I wouldn't use any amount of water on electronic devices. They are plain incompatible.

Against dust, a brush (for paint) is just perfect.

Against finger prints, a dry cloth is efficient. You might add some alcohol if really necessary, but don't put water.

Against more sticky dirt, like ball pen traces, use an eraser.

Ohh dear...   I have been cleaning screens since Aristotle parted the waters. Never had a problem, maybe homer simpson spraying directly to the screen.

Dry cloths & erasers will scuff the appearance of the screen doing more damage then water could ever do.

About my original issue, I don't know the chemistry exactly, but warm screen & warm air give streak free, doing it in cold & you get streaks continuously, maybe the colder air condenses with the still wet screen?

[Intanjir]

If we assume that during thorough wiping we achieve something approaching a uniform solution and suspension of material in the liquid then we might ask why drying doesn't yield something approaching a uniform dried film. Instead the dried film is thicker where you have streaks. I think that this is just because the wet film was thicker in the same spots.

The difference in temperature here is slight so it is surprising that there might be all that much difference in tendency to streak. A lower surface tension would support a more even film. However the surface tension of the liquid is only going to vary slightly. Water varies by about 25% from freezing to boiling. Adding isopropyl lowers surface tension quite a lot in general but it isn't going to radically change the temperature dependence of the surface tension which should be on the order of 10% from 20 to 50 °C.
http://www.aquafoam.com/papers/Vazquez1.pdf