d**a
发帖数: 3715 | 1 polymer沉淀到methanol里面之后，由于颗粒太小，过滤的时候直接通过滤纸怎么办?
谢谢 |
c******h
发帖数: 4573 | 2 选孔径更细的滤纸。
【在 d**a 的大作中提到】
: polymer沉淀到methanol里面之后，由于颗粒太小，过滤的时候直接通过滤纸怎么办?
: 谢谢
|
n*******e
发帖数: 2057 | 3 centrifuge?
【在 d**a 的大作中提到】
: polymer沉淀到methanol里面之后，由于颗粒太小，过滤的时候直接通过滤纸怎么办?
: 谢谢
|
d**a
发帖数: 3715 | |
a*i
发帖数: 1652 | 5 the polymer solution is too diluted.
concentrate it to ~10%, and add MeOH slowly.
【在 d**a 的大作中提到】
: polymer沉淀到methanol里面之后，由于颗粒太小，过滤的时候直接通过滤纸怎么办?
: 谢谢
|
d**a
发帖数: 3715 | 6 I dissolved my polymer (0.3 g) in 10 ml of hot toluene, then drop-wise added
the toluene solution into 400 ml of methanol at r.t. Did I operate
improperly? Thanks. |
a*i
发帖数: 1652 | 7 dissolve it (0.3g) in 3-5 mL toluene (why hot?);
add methanol slowly while stirring the solution until you see precipitation
(add a little more won't hurt).
In this way the precipitate won't be fine powder, and you can decant the
liquid without filtration. IPA will work too.
added
【在 d**a 的大作中提到】
: I dissolved my polymer (0.3 g) in 10 ml of hot toluene, then drop-wise added
: the toluene solution into 400 ml of methanol at r.t. Did I operate
: improperly? Thanks.
|
d**a
发帖数: 3715 | 8 0.3 g of my polymer is insoluble in 10 ml of toluene at r.t. so I have to
heat it up to form a clear solution.
Did you mean I should add the methanol into the toluene solution instead of
adding the polymer solution into methanol? Thanks.
precipitation
【在 a*i 的大作中提到】
: dissolve it (0.3g) in 3-5 mL toluene (why hot?);
: add methanol slowly while stirring the solution until you see precipitation
: (add a little more won't hurt).
: In this way the precipitate won't be fine powder, and you can decant the
: liquid without filtration. IPA will work too.
:
: added
|
a*i
发帖数: 1652 | 9 估计你做沉淀的目的就是要纯化聚合物，
用甲苯加热溶解后，冷却后聚合物溶解性就差了，再加点甲醇可能就沉淀出来了，而杂
质可能还没有沉淀。重复几次就可以了。这样可以避免过滤和离心分离的麻烦。
of
【在 d**a 的大作中提到】
: 0.3 g of my polymer is insoluble in 10 ml of toluene at r.t. so I have to
: heat it up to form a clear solution.
: Did you mean I should add the methanol into the toluene solution instead of
: adding the polymer solution into methanol? Thanks.
:
: precipitation
|
