PNIPAM is a “smart material” which can form a thermo-responsive hydrogel. With a transition temperature in the 30’s and below body temperature, it has seen significant interest in the field of bioengineering.  Potential applications are artificial muscles, wound dressings, engineered tissues and drug delivery.

This chromatogram shows poly(N-isopropylacrylamide) or PNIPAm. It is a promising copolymer candidate for controlled drug release in polymer-drug conjugates.

Solvent0.02 M LiBr DMF
Flow Rate [mL/min]1.00
Column SetI-MBHMW-3078 + I-MBLMW-3078
Column Temp (°C)60.0
Injection volume μL100.0
Concentration [mg/mL]5.80
Mw Weight Average [Da]124,361
Sample dn/dc [mL/g]0.071
Sample IV [dL/g]0.358
PNIPAM Chromatogram
Chromatogram of poly(N-isopropylacrylamide) PNIPAm. Refractive index RI, Viscometer, Right angle light scattering RALS and Low angle light scattering LALS are shown versus elution volume.

PNIPAM -Poly(N-isopropylacrylamide) is a unique temperature-responsive polymer that has been successfully used for drug delivery. Due to its high polarity, it is a very challenging organic material to properly characterize by GPC. The solvent used for this sample was Dimethylformamide (DMF). Data were acquired with the Viscotek TDAmax system.

The 90º (RALS) and the 7º (LALS) light scattering data are clean despite a relatively low dn/dc.

Related application note:  Zetasizer data from PNIPAM coated silica spheres.


If you have any questions, please email me at ulf.nobbmann@malvern.com. Thanks!