| Close |
Message | User | Date(yyyy-mm-dd) |
|
|---|
 |
metal diffusion | bruce | 2002-02-05 | Click here to register. |
|---|
| Does the charge of ions make any difference to the diffusion of them through the membranes? Specifically positive metal ions in the aqueous phase. | | |
| jpartee | 2002-02-05 | Click here to register. |
|---|
 | Yes, charge does make a difference. The isoelectric point of the Cellulose ester membrane is 2.2 and RC is 3.0. Any pH above this will result in a negative charge. |
| | |
| bruce | 2002-02-05 | Click here to register. |
|---|
| Sorry, this isn't very clear to me.
Will positively charged ions such as Mg2+, Na+, Li+ and Ca2+ pass through the membrane when they are in their aqueous form? |
| | |
| dave | 2002-02-05 | Click here to register. |
|---|
| Metal ions such as you list, as well as most other inorganic ions, diffuse rapidly through laboratory dialysis tubing. These ions are so much smaller, even when hydrated, than dialysis tubing pores that these ions move as freely as the water molecules themselves.
Any charge on a cellulose membrane is rather diffuse and should not signifigantly affect small ion transport. |
| | |
| jpartee | 2002-02-06 | Click here to register. |
|---|
| It depends on the pH of the membrane. If the membrane is negatively charged, the ions will not pass through very easily.
|
| | |
| bruce | 2002-02-07 | Click here to register. |
|---|
| What pH do the membranes come in? Do the different membrane materials make the diference or is this something that can be altered on all of them? |
| | |
| jpartee | 2002-02-07 | Click here to register. |
|---|
| The membranes have an isoelectric point of about 2.5 and any pH above that will make the membrane slightly negatively charged. The material does not make a difference since they are both a form of cellulose.
|
|
|
| Thanks for visiting.- To ask question or answer a question, you need to register here.
- You can browse by clicking on a message subject to see the complete message.
- If you have previously registered, you can log in below.
|
|
Back to Top
Oldest
Newer