<B0101>
I was thinking about a way to produce HF, I think we can make HF by this reaction: CaF2 + H2SO4 --> CaSO4 + 2 HF, but then I can't find a suitable reaction vessel
<Sync_>
get stainless pickling solution
<Sync_>
or let someone buy you HF that is able to procure it
<B0101>
We can procure HF (only through drain cleaners), but the solution has a lot of impurities in it
<berndj>
B0101, there was a guy on the amateur telescope making list who said he used CaF2 + HCl to help with grinding
<Sync_>
that's what I meant, try to get it pure
<Sync_>
maybe in glass etching solution
<berndj>
and yes, AFAIK CaF2 + H2SO4 is the primary way that HF gets produced
<berndj>
(or was that for F2 itself, but that's a small hop from there to HF)
<berndj>
B0101, what do you mean by "suitable reaction vessel"?
<B0101>
berndj: I wanted to make HF, but I know I cannot use glass or metals
<berndj>
why not metals?
<berndj>
HF should passivize them
<B0101>
I was thinking HF would react with the metals, but then for now, I'd follow Sync_'s advice and I would try glass etching chemicals first
<berndj>
it's the H2SO4 that would attack the metal
<B0101>
berndj: Copper? will it work?
<berndj>
and i have to wonder if glass is "good enough" if not "imperfect"
<berndj>
what concentration of H2SO4 will you use? that could make all the difference
<berndj>
B0101, AFAIK HF gets transported in big nickel (or nickel-lined; that stuff is expensive) tanks
<berndj>
maybe stainless steel is close enough? surely this is something you can figure out empirically
<Sync_>
plastic containers also work
<Sync_>
stainless also works
<berndj>
yeah, polyethylene is ok with HF
<Sync_>
but it depends on concentration
<B0101>
berndj: I am thinking of taking copper sulfate and performing electrolysis with a platinum and copper anodes and cathodes to get H2SO4, then boiling it down to get pure H2SO$
<berndj>
not sure about H2SO4 though! HF + H2SO4 is a nasty combination!
<B0101>
*H2SO4
<berndj>
isn't that called "piranha water"?
<Sync_>
that is one dangerous reaction to do B0101
<Sync_>
I'd rater much not be there when it happens
<berndj>
i don't think H2SO4 works like that - "boiling it down"
<berndj>
you get H2O boiling off, sure, but also SO3 gas
<berndj>
personally i'd go the other way, and make H2SO4 from SO3 - but turning SO2 into SO3 is the step i'm less confident about
<berndj>
B0101, can you get HF and fairly concentrated H2SO4 of basically any purity?
<B0101>
If I am buyinf for my home lab, I only can get maximum 10% of H2SO4 and HF from drain cleaners (purity not known)
<B0101>
*buying
<berndj>
if so, maybe use the impure HF to passivize your metal reaction vessel, then do the CF2 + H2SO4 trick and let the evolving HF gas bubble through water
<Sync_>
h2so4 is found in battery acid
<Sync_>
usually pretty clean
<berndj>
and pretty concentrated too, right?
<Sync_>
also getting that stuff metal free is an issue, I guess it is not much worth if you have HF afterall when it is still contaminated
<Sync_>
yeah
<berndj>
or don't bother passivating, just sacrifice a reaction vessel when it's too damaged
<berndj>
Sync_: that's why i suggest bubbling the gas through water; metal ions should stay behind, i'd think
<Sync_>
we are talking ppb here
<berndj>
oooh, i didn't know that :)
<berndj>
i thought we were doing kitchen chemistry where ppt would be good enough!
<Sync_>
afterall this is #homecmos :P
<Sync_>
yeah I guess it'd work
<Sync_>
but really
<Sync_>
that is far too dangerous
<berndj>
azonenberg seems to think it's #homemems, tsk tsk
<Sync_>
making HF from scratch is a huge issue
<berndj>
of course!
<berndj>
B0101: when you do CaF2 + H2SO4, don't sniff the beaker! :D
<Sync_>
looking at the safety instructions at work I'd really not want to go down that road
<Sync_>
using HF is fine but eh. making it
<B0101>
I remember that some people purify HCl by placing 2 containers in a tank (1 filled with water and another filled with HCl) , sealing it and waiting about 2 weeks to get pure acid
<B0101>
I'm not sure if it works for HF
<berndj>
B0101, it would depend on which impurities you have, and their vapour pressures and evaporation rates
<B0101>
I am not sure if we can make a plastic condenser unit
<B0101>
anyway, how can you remove surfacants from NaOH?
<Sync_>
buying it pure from the hobby pcb shop or photographers supply
* B0101
thinks that quite a lot of chemical she owns are from drain cleaners or self synthesized
<B0101>
Sync_: Photography shops here doesn't carry NaOH
<Sync_>
I usually try to buy technical grad or better depending on what I need
<Sync_>
wat
<B0101>
If the photogrpahy shops or electronics shops have NaOH, I wouldn't try getting NaOH from drain cleaners
<B0101>
*photography
<Sync_>
where do you live that procuring chemicals is even more of an issue than in germany?
<B0101>
Singapore
<Sync_>
I'd think that getting chemicals there would be easier
<B0101>
quite alot of common chemical appears in the list
<Sync_>
uh
<B0101>
I think even NaOH, KOH, HCl and HNO3 are included in there
<Sync_>
naoh and koh is on there
<B0101>
sulfuric acid too
<B0101>
I think you get the idea now
<Sync_>
that is messed up
<azonenberg>
B0101: anionic surfactants in >5% concentration - aka any strong detergent
<azonenberg>
o_O
<azonenberg>
FeCl3 is
<azonenberg>
Acetic acid, but only >80%
<azonenberg>
HCl at >9%? o_O
<azonenberg>
HF at >2% i can somewhat understand
<azonenberg>
HNO3 >9% o_O
<azonenberg>
B0101: So what does it take to get the things on that list?
<B0101>
Black market
<azonenberg>
wait, they cant be legally obtained at all?
<B0101>
for personal use, no
<azonenberg>
o_O
<Sync_>
yeah azonenberg it is pathetic
<Sync_>
NaOH and KOH is on there
<Sync_>
????
<azonenberg>
Yeah
<azonenberg>
thats ridiculous
<azonenberg>
basically every possible drain cleaner is
<azonenberg>
H2SO4 too
<Sync_>
yep
<B0101>
I have talked to a friend who is a police officer, he says that the rules here are actually set to prevent people from home experimentation, not anything else
<azonenberg>
lol what?
<azonenberg>
i was going to say most of those things didnt seem to have obvious drug/explosives uses
<B0101>
Because we have big science companies like GlaxoSmithKline and others, and he says that they're afraid that some home experimenter will discover something big, which may put those companies out of business here
<azonenberg>
Lol
<azonenberg>
Ok, one more reason not to move to singapore (not that i was planning to do so anyway)
<B0101>
That's why people smuggle chemicals in here
<B0101>
And I have to buy from the black market or people who smuggle them in
<B0101>
Funny thing is, Singapore tries to portray itself as a science and tech hub
<B0101>
its absolutely crazy!
<B0101>
In my head: a little voice screams: I want to do science! but then I can't because of all these rules
<Sync_>
yeah reason to move abroad
<superkuh>
I had a fire marshal tell me it was illegal to have a couple gallons of battery acid in my apartment. (USA)
<superkuh>
He made me "dispose" of it with a commercial company. >$500 and that was with huge discounts from the company pickup guy who was actually very nice.
<B0101>
I have no idea what to say...
<Sync_>
yeah getting basic acids has been getting easier here since again
<B0101>
I have been subjected to random checks at train stations for idk what reason
<B0101>
I even think of getting a bike to go to work
<B0101>
I don't want to be checked every time at train stations
<B0101>
I guess I am moving out of this country
<Sync_>
that is a good idea
<B0101>
I'm not sure where is a good place though
<B0101>
I think I want to go somewhere (thailand maybe) and build a underground lab
<B0101>
Is there any film material that turns dark when electricity is applied?
<soul-d>
donno have read on stuff like that in combination with windows
<soul-d>
only in my imagination wich i can assure you is of little help in reality
<Sync_>
azonenberg: iirc there is something done like that
<Sync_>
but only experimental
<azonenberg>
Sync_: yeah, i was wondering what the reason for that was
<Sync_>
money
<azonenberg>
judging by how hard the semi world has been trying to eliminate wet processing
<soul-d>
like there is the copper reaction common in chemistry with sugar so i was thinking maybe one could grow copper stuff (in particular those the nm formation where research is being done on )
<Sync_>
litho is the singlemost expensive step in CMOS
<azonenberg>
i'm just surprised this process stayed wet
<Sync_>
and there are not alot of companies making equipment
<azonenberg>
Sync_: doesn't that mean it would be the one people try hardest to optimize?
<azonenberg>
You can use the same exposure system
<Sync_>
yeah but I guess it did not pan out
<azonenberg>
you'd just need a different resist chemistry
<soul-d>
maybe wet is less suseptable to conatmination ?
<soul-d>
like dust ?
<azonenberg>
Seems unlikely
<azonenberg>
normally dry processes are preferred for better uniformity etc
<Sync_>
well probably the fear is adopting something that is not tested very good
<Sync_>
because fabs are now getting so expensive that they have to be shared by different vendors
<soul-d>
mmm those fabs are second in research they are ones who apply