Study of Transport Properties of Polyelectrolyte-Cellulose Acetate Membranes

Activity: Talk or presentation typesConference presentation

Janina Hakanpää - Contributor

Kirsi Yliniemi - Speaker

Benjamin Wilson - Contributor

Ferdinand Singer - Contributor

Sarah Höhn - Contributor

Eero Kontturi - Contributor

Sannakaisa Virtanen - Contributor

The rapid and uncontrollable corrosion of Mg and Mg based alloys is one of the main obstacles in the development of Mg based temporal implant materials1,2; the potentially harmful corrosion products leading to the increase of local pH and release of H2 gas to the surrounding tissues are especially problematic. Therefore, the control over the dissolution rate and release of corrosion products is of high importance if Mg based materials are to be used as temporary biomedical implants. Earlier, the authors have developed a weak polyelectrolyte-cellulose acetate membrane (poly(N,N-dimethylaminoethyl methacrylate)-cellulose acetate=PDMAEMA:CA membrane), which can simultaneously control the dissolution rate of Mg as well as protect the surrounding environment from the high pH increase and H2 gas3.
In the present study, scanning electrochemical microscope (SECM) was used to investigate the transport properties of these membranes in more details. The results show that the PDMAEMA content controls the permeability of the membrane but also, a surprising time-dependent behaviour was observed: the permeability of the PDMAEMA:CA membranes decreased as a function of time and ellipsometer results showed that this behaviour is not related to the swelling of the membrane. Instead, the time-dependent behaviour might be an indicator of the conformational change of PDMAEMA molecules – either due to the screening of charges or change in degree of ionisation - blocking the membrane pores and this results in a change in permeability as a function of time. A material with such a time-dependent behaviour is an extremely interesting candidate when designing smart and responsive coatings and membranes for temporal biomedical implants.
(1) F. Witte, N. Hort, C. Vogt, S. Cohen, K. U. Kainer, R. Willumeit, F. Feyerabend, Current Opinion in Solid State and Materials Science, 2008, 12, 63-72.
(2) S. Virtanen, Mater. Sci. Eng. B, 2011, 176, 1600-1608.
(3) K. Yliniemi, B. P. Wilson, F. Singer, S. Höhn, E. Kontturi S. Virtanen, ACS Applied Materials and Interfaces, 2014, 6, 22393-22399.

27 May 20172 Jun 2017

Event (Conference)

TitleElectrochemical Society Meeting
CityNew Orleans
CountryUnited States
Degree of recognitionInternational event

Research units

ID: 13840218