Real-time adsorption of optical brightening agents on cellulose thin films

Carina Sampl, Samuel Eyley, Wim Thielemans, Ulrich Hirn*, Stefan Spirk

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Optical brightening agents (OBAs) are commonly used in textile and paper industry to adjust product brightness and color appearence. Continuous production processes lead to short residence time of the dyes in the fiber suspension, making it necessary to understand the kinetics of adsorption. The interaction mechanisms of OBAs with cellulose are challenging to establish as the fibrous nature of cellulosic substrates complicates acquisition of real-time data. Here, we explore the real-time adsorption of different OBAs (di, tetra- and hexasulfonated compounds) onto different cellulose surfaces using surface plasmon resonance spectroscopy. Ionic strength, surface topography and polarity were varied and yielded 0.76–11.35 mg m−2 OBA on cellulose. We identified four independent mechanisms governing OBA-cellulose interactions. These involve the polarity of the cellulose surface, the solubility of the OBA, the ionic strength during adsorption and presence of bivalent cations such as Ca2+. These results can be exploited for process optimization in related industries as they allow for a simple adjustment and experimental testing procedures including performance assessment of novel OBAs.
Original languageEnglish
Article number117826
JournalCarbohydrate Polymers
Publication statusPublished - Jun 2021


  • Adsorption
  • Cellulose thin film
  • Cellulose xanthate
  • Optical brightening agent
  • Surface plasmon resonance spectroscopy
  • Trimethylsilyl cellulose

ASJC Scopus subject areas

  • Materials Chemistry
  • Polymers and Plastics
  • Organic Chemistry

Fields of Expertise

  • Advanced Materials Science

Cite this