Dear Nair N.A, what is meant by interaction? Hydrophobically modified polyacrylic acid show enhanced interactions in water solutions. My Regards

Hi;

I did not fully understand your question, but I think that the acrylic acid can be modified to be hydrophobic. This process is achieved by the copolymerization of acrylic or methacrylic acid - which is hydrophilic - with polymers which have long lipophilic aliphatic chains of 10 to 30 carbon atoms: polyalkyl esters or glycol.

With my best regards

I also do not fully understand your question. Are you talking about a polyacrylic acid block in a block-copolymer?

The first and easiest way to make polyacrylic acid more hydrophobic is to lower pH to e.g. 3. At this pH the chain will be fully protonated and no macroion anymore. Hence, solubility will go down. We have abserved this in PNIPAM-Poly(acrylic acid) copolymer microgels. At low pH and above the LCST of PNIPAM these particles aggregate. At high pH they are colloidally stable due to the COO- groups.

Please have a look at:

Article Influence of Charge Density on the Swelling of Colloidal Pol...