Computational modeling of Protein based super-absorbents from waste
2011 (English)Conference paper, Poster (Other academic)
Hydrogels are used for various applications, for example as transporters in drug delivery, in
control lenses, and as superabsorbent material in diapers. Most synthetic produced hydrogels
are based on synthetic polymers. Even though they are efficient and cheap, they are not
biodegradable and sometimes even toxic.
To produce more environmental friendly and biodegradable superabsorbent polymers (Bio-
SAPs), other building blocks can be used, such as polysaccharides and various protein
structures, for example fish shells, collagen, soy protein and egg protein. Experimental
studies at the University of Boras show that it is possible to produce Bio-SAPs from by-products
of ethanol production from ligno-cellulose.[2, 6, 7]
We have studied the absorption properties of protein structures in silico as a comparison to
experimental studies. The NPT Gibbs Ensemble Monte Carlo (GEMC) simulation scheme with
two phases is used in order to calculate the absorption capacity of the protein. Pure water was
simulated in the first GEMC-phase and the peptide in the second phase. The simulations were
made with SPC/E water model  and the AMBER99 atomistic force field for the peptides .
Furthermore, mesoscopic studies with coarse grained force fields have been done.
To facilitate faster computations, we used cell lists for the atom-atom interactions,
configurational bias algorithm to build the water molecules and the peptide side-chains, and the
cavity bias algorithm  for molecule insertions.
Model peptides have been studied with varying secondary structure, temperature and
protonation (pH). We also plan to study how cross-links affect the absorption. One of the peptides
we study is a 20 amino acid long peptide called SSP1. This peptide is designed to form a
fibrous structure a hydrogel, and its structure is well defined. We have also studied a peptide
which changes secondary structure when changing the pH, and concentration. This makes it
possible to compare absorption properties with respect to the secondary structure.
We have simulated peptides with the Gibbs Ensemble Monte Carlo scheme in order to study
the water absorption rate dependent of structure, charge, pH and temperature. This information is
useful when developing new biodegradable superabsorbent materials.
Place, publisher, year, edition, pages
superabsorbents, gibbs ensemble monte carlo, resouce recovery
Energi och material
Theoretical Chemistry Other Industrial Biotechnology
Research subject Resource Recovery
IdentifiersURN: urn:nbn:se:hb:diva-6609Local ID: 2320/9127OAI: oai:DiVA.org:hb-6609DiVA: diva2:887305
Thermodynamics2011, September 1st – September 3rd 2011, Athens, Greece