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Why is my PVDF solution for electrospinning turning fuzzy and brown.?
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+ Polymer chemistry
+ Polymer nanocomposites
+ Electrospinning
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Manuel Nelson
Why is my PVDF solution for electrospinning turning fuzzy and brown.?
The changing in the color of PVDF/DMF solution to brown should be attributed to the changing in properties of DMF under heating. You can try that by heating only DMF without PVDF, the same brown color will be observed.
The changing in the color of PVDF/DMF solution to brown should be attributed to the changing in properties of DMF under heating. You can try that by heating only DMF without PVDF, the same brown color will be observed.
Hello, I also used DMF as solvent for PVDF. I had difficulties dissolving the PVDF pellets at room temp. so I employed heating up to 70 deg C. Soon after, I noticed a solution color transition from clear to brown. I am wondering if this is normal as I made sure the bottles and equipment I used are well washed.
Hello, I also used DMF as solvent for PVDF. I had difficulties dissolving the PVDF pellets at room temp. so I employed heating up to 70 deg C. Soon after, I noticed a solution color transition from clear to brown. I am wondering if this is normal as I made sure the bottles and equipment I used are well washed.
Not only PVDF but also include PAN in DMF, too. Even there is no different and interfere during electrospinning but its caused a little frustrated to use.
Not only PVDF but also include PAN in DMF, too. Even there is no different and interfere during electrospinning but its caused a little frustrated to use.
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf... My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown. Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale. My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf... My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown. Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale. My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf... My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown. Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale. My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf... My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown. Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale. My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
I too have the same observation. But I disagree with the change in properties of DMF since i observed it only for high concentration of PVDF. Also, the clear solution turns golden brown after storing it for a long time. I agree with Shuting Chen . The reason could be cross linking of polymers or C=C conjugation. Should be confiremed with NMR and XPS.
I too have the same observation. But I disagree with the change in properties of DMF since i observed it only for high concentration of PVDF. Also, the clear solution turns golden brown after storing it for a long time. I agree with Shuting Chen . The reason could be cross linking of polymers or C=C conjugation. Should be confiremed with NMR and XPS.
The changing in the color of PVDF/DMF solution to brown should be attributed to the changing in properties of DMF under heating. You can try that by heating only DMF without PVDF, the same brown color will be observed.
The changing in the color of PVDF/DMF solution to brown should be attributed to the changing in properties of DMF under heating. You can try that by heating only DMF without PVDF, the same brown color will be observed.
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Hello, I also used DMF as solvent for PVDF. I had difficulties dissolving the PVDF pellets at room temp. so I employed heating up to 70 deg C. Soon after, I noticed a solution color transition from clear to brown. I am wondering if this is normal as I made sure the bottles and equipment I used are well washed.
Hello, I also used DMF as solvent for PVDF. I had difficulties dissolving the PVDF pellets at room temp. so I employed heating up to 70 deg C. Soon after, I noticed a solution color transition from clear to brown. I am wondering if this is normal as I made sure the bottles and equipment I used are well washed.
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Most welcome Chen
Most welcome Chen
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Not only PVDF but also include PAN in DMF, too. Even there is no different and interfere during electrospinning but its caused a little frustrated to use.
Not only PVDF but also include PAN in DMF, too. Even there is no different and interfere during electrospinning but its caused a little frustrated to use.
More
VOTE
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf...
My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown.
Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale.
My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf...
My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown.
Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale.
My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
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Is it possible to electrospin the solution with NMP a a solvent?
Regards
Emad
Is it possible to electrospin the solution with NMP a a solvent?
Regards
Emad
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Would you please describe the method used to obtain this solution? (Temperature, time. need to stir?)
Would you please describe the method used to obtain this solution? (Temperature, time. need to stir?)
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you can try with NMP, I have made a transparent solution of PVDF with NMP
you can try with NMP, I have made a transparent solution of PVDF with NMP
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I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf...
My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown.
Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale.
My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
I crushed the Pvdf pellets in a hot press (room temp) before dissolving at 60deg C. It does turn orangish brown and as you cool it, the color gets paler but not completely clear. But this is not a problem for electrospinning. Here's how my experience goes with Pvdf...
My first experience with PVDF (530K Mw) in DMF(sigma)/THF(mtedia):: 1/1 was a clear solution. Another thing to note, my solvents were new: anhydrous. Following this, I added OG Poss for one of my studies, which turned my pvdf solution into orangish brown.
Hereafter, all my attempts with Pvdf(530K &180K) in Dmf (without poss) were orangish brown (solvents are not new).when I tried to change the solvent sys to Dmac, Thf the solution was brown at higher temperature but became clear at room temp.Yet another thing I observed is, when I use water bath to heat the polymer solution (80 deg C), the color is darker. I put it out on hot plate (60 deg C), the solution turns pale.
My first attempt at spinning Pvdf (530k) was successfull but not the following attempts (regardless of solvent system). Either the fibers had clumps or branches. Both of which were undesirable. Instead, I am now using Pvdf with 180K mw. In this case also, the solution in dmf/thf is brown in color. Resulting fibers are relatively uniform in diameter and surface wetting is 137 deg ( repeatedly). With this, I am confident that brown solution doesnt interfere with electrospinning.
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I too have the same observation. But I disagree with the change in properties of DMF since i observed it only for high concentration of PVDF. Also, the clear solution turns golden brown after storing it for a long time. I agree with Shuting Chen . The reason could be cross linking of polymers or C=C conjugation. Should be confiremed with NMR and XPS.
I too have the same observation. But I disagree with the change in properties of DMF since i observed it only for high concentration of PVDF. Also, the clear solution turns golden brown after storing it for a long time. I agree with Shuting Chen . The reason could be cross linking of polymers or C=C conjugation. Should be confiremed with NMR and XPS.
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I have the same situation and I recommend answer of Viswanath Pamarti - it is brown because of storing it for a long time.
I have the same situation and I recommend answer of Viswanath Pamarti - it is brown because of storing it for a long time.
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