Parameters under Dip TIPS study with the information about tested variables and other constant conditions followed* (n = 6).

* First, the effect of the polymer type was tested and the polymer giving the optimal results was selected for the subsequent experiment. Next, the effect of molecular weight was tested and the polymer with best results was selected for the test of the polymer concentration. Having selected polymer parameters, we then progressively optimized the process conditions. The parameter fixed after each step is marked in bold font.Parameters under Dip TIPS study with the information about tested variables and other constant conditions followed* (n = 6).