Speaker
Description
The growing awareness of environmental issues is driving the printing industry towards the use of water-based inks. These type of inks typically contain water, cosolvents, surfactants, pigments and polymeric particles [1]. To optimize the print quality, a thorough understanding of the transport of all ink components in thin porous media is needed. A lot of research on surfactants in porous media has been done [2], [3], [4]. However, these studies show that the effect of surfactants is highly dependent on the specific surfactants – substrate combination and is still poorly understood.
It is challenging to measure liquid uptake inside paper because it requires high spatial and temporal resolutions. An ultra-fast NMR-based imaging technique [5] (figure 1) was therefore developed for this purpose.
To study the transport of surfactant solutions through the porous medium, spatially dependent liquid distributions are followed over time. Figure 2 shows the average NMR signal inside unsized uncoated paper, which is a measure for the moisture content, over time for solutions with different concentrations of sodium dodecyl sulfate (SDS). From these measurements, it is concluded that the surfactant concentration does not influence the penetration speed in the thickness direction. Nevertheless, differences in wetting and lateral penetration are observed at the top surface. The latter two processes happen on a larger time scale compared to penetration in the thickness direction. It is suggested that adsorption of surfactants on the medium does not happen om the timescale of liquid penetration or adsorption causes immediate surfactant depletion. In both cases, this may result in negligible effects of surfactant concentration on the penetration speed.
| References | [1] A. Kamyshny and S. Magdassi, “Inkjet ink formulations,” Inkjet-based Micromanufacturing, pp. 173–189, May 2012, doi: 10.1002/9783527647101.CH12. [2] B. Simončič and V. Rozman, “Wettability of cotton fabric by aqueous solutions of surfactants with different structures,” Colloids Surf A Physicochem Eng Asp, vol. 292, no. 2–3, pp. 236–245, Jan. 2007, doi: 10.1016/J.COLSURFA.2006.06.025. [3] L. Labajos-Broncano, J. A. Antequera-Barroso, M. L. González-Martín, and J. M. Bruque, “An experimental study about the imbibition of aqueous solutions of low concentration of a non-adsorbable surfactant in a hydrophilic porous medium,” J Colloid Interface Sci, vol. 301, no. 1, pp. 323–328, Sep. 2006, doi: 10.1016/J.JCIS.2006.04.076. [4] G. Venditti, V. Murali, and A. A. Darhuber, “Inkjet printing of surfactant solutions onto thin moving porous media,” Colloids Surf A Physicochem Eng Asp, vol. 634, Feb. 2022, doi: 10.1016/j.colsurfa.2021.127832. [5] R. J. K. Nicasy, H. P. Huinink, S. J. F. Erich, O. C. G. Adan, and N. Tomozeiu, “Ultra Fast Imaging NMR method for measuring fast transport processes in thin porous media,” Magn Reson Imaging, vol. 103, pp. 61–74, Nov. 2023, doi: 10.1016/J.MRI.2023.06.009. |
|---|---|
| Country | The Netherlands |
| Acceptance of the Terms & Conditions | Click here to agree |
