Increase in salt concentration (NaCl) in presence of block copolymer can generally increase the mesopore diameter and decrease the no of micropore. Is there any way that it can increase the surface area and no of mesopore somehow? Please reply.
You need to use the term specific surface area of the copolymer pores. Increase the mesopore diameter is decrease specific surface area of the copolymer pores. The addition of Na Cl should increase the specific surface area. In the theory of salting in / salting out there is a series of H. Hofmeister. NaCl is a salting out. NaI, NaSCN, urea are salting in. Urea should decrease the specific surface area.
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Thanks for the reply Sir.
NaCl in the borderline in Hofmeister series. Although on the borderline, It is typically known to cause the salting-out effect. I think NaCl causes dehydration of the corona and increase the core size of the micelle leads increase in mesopore size and as a result decrease in specific surface area of the copolymer pores. Thats what is explained in the attached paper as well. Please correct me if I am wrong.
I found that NaCl causes increase in aggregation no of blcok copolymer as a result more monomer comes to form micelle and their long hydrophilic chain involves in formation of micropore. thats why sometimes micropore volume increases with increasing concentration of salt.
But my querry is wheather salting out effect can somehow increase mesopore volume or no of mesopore and surface area (if there is not any micropore)?
Thanks for your reply Sir.
When I am synthesizing some material (like silica) using block copolymer as a template and I am increasing NaCl concentration. After the synthesis I am removing the template to create pores. And the final surface area (observed by BET) of the material I am talking about. Thats why I mentioned the term " block copoymer templated mesoporous material". sorry if there is any misunderstanding happened.
The specific surface of the porous material is determined by the BET method. Your nanoparticles or silica mesoparticles are distributed in size. Therefore, you get the pore size distribution. BET gives the average specific surface area of the pores.
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