Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
Growing a CuSO4 crystal using a "hydrothermal" process
I thought I'd have a crack at growing a copper sulfate crystal using a setup based on hydrothermal crystal growing methods. Obviously I don't need
high pressures or temperatures for CuSO4, so I built a simple setup using a 2000ml measuring cylinder and a cheap Chinese coffee cup warmer (~20W).
This is really just a proof of concept - no attempt has been made to optimize the process.
Initial setup:
1: A 2000ml measuring cylinder, with its plastic base removed, is placed on a heating plate (coffee cup warmer). I used a lab stand for extra
stability as I have a kitten whose middle name is "trouble".
2: 1800ml of saturated CuSO4 solution @50C is added, along with 200g of solid CuSO4.
3: The bottom 1/4 of the cylinder is wrapped in insulation, a cover is added, and the heater is turned on.
4: The system is left to equilibriate for several days.
5: A small seed crystal is suspended in the top 1/4 of the cylinder.
My initial seed was about 9mm long. After 3 days it is already significantly bigger. I don't want to disturb the process by pull it out and measuring
it so I'm trying to take pics through the cylinder.
At any rate, it looks like the process is working. It has a couple of nice advantages: Its sealed so there's no water loss, so no need to top up. And
condensation at the top is continually washing the glass so there's no crust growing up the sides.
The photos are of the initial seed, then 3 days later. The last photo shows my setup (with the insulation pulled aside to show the heater and solid
CuSO4)
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
Ubya
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1247
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
|
|
very intresting![;)](./images/smilies/wink.gif)
a few weeks ago i was thinking to use the same process to make sulphur crystals from a saturated solution of toluene and sulphur, if it worked with
CuSO4 i will definitely give it a shot
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
The crystal is now ~40mm long. I'd post a pic, but unfortunately my phone turned into a brick yesterday.
I don't see why this wouldn't work with toluene - and it has the added bonus of no toluene vapor to get rid of.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
elementcollector1
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 2684
Registered: 28-12-2011
Location: The Known Universe
Member Is Offline
Mood: Molten
|
|
Now if only there was a low-pressure hydrothermal method of growing quartz... I'd be all over that.
Elements Collected:52/87
Latest Acquired: Cl
Next in Line: Nd
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
Yesterday I turned off the heater, as prep for terminating the experiment. This was a mistake - the crystal grew fast overnight, and at some point the
suspension broke and it landed in the solid mess at the bottom. Result was not pretty. It did weigh 90g though - this is after 19 days growth.
I had noticed a missing corner on the crystal earlier - I think this was due to a less than perfect seed. Going to try again with a better seed. This
is definitely a fairly quick way to grow large crystals.
My phone died last week, so no pic of the result sorry.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
Ubya
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1247
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
|
|
Quote: Originally posted by Twospoons ![](images/xpblue/lastpost.gif) | at some point the suspension broke and it landed in the solid mess at the bottom. Result was not pretty. It did weigh 90g though - this is after 19
days growth. |
that's unfortunate![:(](./images/smilies/sad.gif)
anyway, wow 90g!
i need to find a coffee mug heater and try it, bad news is that in italy they are not something common to find so probably i need to go to my trusty
ebay and wait 1 month for a shipment from china...
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
I got my heater from china - on Aliexpress. I've bought quite a lot of stuff that way, and only encountered issues a couple of times.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
Second attempt. This took about a week and a half to grow to this size. It has unfortunately sprouted a twin on one side.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
Ubya
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1247
Registered: 23-11-2017
Location: Rome-Italy
Member Is Offline
Mood: I'm a maddo scientisto!!!
|
|
Quote: Originally posted by Twospoons ![](images/xpblue/lastpost.gif) | Second attempt. This took about a week and a half to grow to this size. It has unfortunately sprouted a twin on one side.
|
pretty damn fast.
what is the temperature in the hot and cold sides?
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
At the top, and in fact most of the way down, its 34C. Right at the bottom, on top of the bulk CuSO4, its 42C.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
blogfast25
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
I'm trying to set up a similar experiment.
How did you measure the temperature of the hot zone?
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
I just stuck a thermocouple into cylinder, briefly.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
blogfast25
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
I've water-proofed a thermocouple but I'm getting low temperatures (< 30 C) at the bottom. Need more patience, I guess...
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
As I recall it took a while for the temperature profile to establish and stabilise, by which I mean many hours. Insulation around the bottom helps,
as does having a stable room temperature.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
blogfast25
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
I'm using a 1 litre measuring cylinder with the base stands cut off and the bottom quarter insulated with expandec LDPE. I use an old hot plate on a
very low setting.
I'm getting about 45 C at the bottom, so great, right? Trouble is that the top temperature is only 2 - 3 degrees lower...
Looks like I need myself some cooling fins! ![:(](./images/smilies/sad.gif) ![:D](./images/smilies/biggrin.gif)
[Edited on 16-3-2023 by blogfast25]
|
|
Twospoons
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1311
Registered: 26-7-2004
Location: Middle Earth
Member Is Offline
Mood: A trace of hope...
|
|
I honestly dont know how much delta T is needed for this to work - probably depends a lot on the solubility vs T curve. And will be limited by how far
you can go into super-saturation before stuff just spontaneously crystalizes.
Helicopter: "helico" -> spiral, "pter" -> with wings
|
|
Fulmen
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 1702
Registered: 24-9-2005
Member Is Offline
Mood: Bored
|
|
Your approach is a bit one-sided. Yes, for rapid crystal growth you want a large dT, but this also increases the risk of defects. The slower you grow
the crystals the better it will be. So the real answer is "it depends on your setup" and requires some patience on your behalf.
Although measurements are useful the most important thing here will be repeatability and stability. The setup should be well defined and done in a
temperature controlled environment. The heat source can be any stable (resistive) load like a heating element or light bulb. I would avoid regulated
heat sources (at least initially) as they could induce switching fluctuations.
We're not banging rocks together here. We know how to put a man back together.
|
|
blogfast25
International Hazard
![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif) ![*](images/xpblue/star.gif)
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Fulmen ![](images/xpblue/lastpost.gif) | Your approach is a bit one-sided. Yes, for rapid crystal growth you want a large dT, but this also increases the risk of defects. The slower you grow
the crystals the better it will be. So the real answer is "it depends on your setup" and requires some patience on your behalf.
Although measurements are useful the most important thing here will be repeatability and stability. The setup should be well defined and done in a
temperature controlled environment. The heat source can be any stable (resistive) load like a heating element or light bulb. I would avoid regulated
heat sources (at least initially) as they could induce switching fluctuations. |
Agreed with everything, especially your openiing sentence.
But "I would avoid regulated heat sources [...]" probably isn't a measurable effect because of the thermal inertia of the solution column.
|
|
Texium
|
Thread Moved 30-11-2023 at 10:55 |