A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
Effect of Particle Interactions on the Assembly of Drying Colloidal Mixtures
Tekijät: Tinkler, James D.; Scacchi, Alberto; Argaiz, Maialen; Tomovska, Radmila; Archer, Andrew J.; Willcock, Helen; Martin-Fabiani, Ignacio
Kustantaja: AMER CHEMICAL SOC
Kustannuspaikka: WASHINGTON
Julkaisuvuosi: 2022
Journal: Langmuir
Tietokannassa oleva lehden nimi: LANGMUIR
Lehden akronyymi: LANGMUIR
Vuosikerta: 38
Numero: 18
Aloitussivu: 5361
Lopetussivu: 5371
Sivujen määrä: 11
ISSN: 0743-7463
eISSN: 1520-5827
DOI: https://doi.org/10.1021/acs.langmuir.1c03144
Tiivistelmä
The effects of particle interactions on the size segregation and assembly of colloidal mixtures during drying were investigated. A cationic surfactant was added to a binary latex/silica colloidal dispersion that has been shown to self-stratify upon drying at room temperature. Atomic force microscopy was used to show that the change in particle interactions due to the presence of surfactants reduced the degree of stratification and, in some cases, suppressed the effect altogether. Colloidal dispersions containing higher surfactant concentrations can undergo a complete morphology change, resulting instead in the formation of armored particles consisting of latex particles coated with smaller silica nanoparticles. To further prove that armored particles are produced and that stratification is suppressed, cross-sectional images were produced with energy-dispersive X-ray spectroscopy and confocal fluorescence microscopy. The growth of armored particles was also measured using dynamic light scattering. To complement this research, Brownian dynamics simulations were used to model the drying. By tuning the particle interactions to make them more attractive, the simulations showed the presence of armored particles, and the size segregation process was hindered. The prevention of segregation also results in enhanced transparency of the colloidal films. Overall, this research proves that there is a link between particle interactions and size segregation in drying colloidal blends and provides a valuable tool to control the assembly of different film architectures using an extremely simple method.
The effects of particle interactions on the size segregation and assembly of colloidal mixtures during drying were investigated. A cationic surfactant was added to a binary latex/silica colloidal dispersion that has been shown to self-stratify upon drying at room temperature. Atomic force microscopy was used to show that the change in particle interactions due to the presence of surfactants reduced the degree of stratification and, in some cases, suppressed the effect altogether. Colloidal dispersions containing higher surfactant concentrations can undergo a complete morphology change, resulting instead in the formation of armored particles consisting of latex particles coated with smaller silica nanoparticles. To further prove that armored particles are produced and that stratification is suppressed, cross-sectional images were produced with energy-dispersive X-ray spectroscopy and confocal fluorescence microscopy. The growth of armored particles was also measured using dynamic light scattering. To complement this research, Brownian dynamics simulations were used to model the drying. By tuning the particle interactions to make them more attractive, the simulations showed the presence of armored particles, and the size segregation process was hindered. The prevention of segregation also results in enhanced transparency of the colloidal films. Overall, this research proves that there is a link between particle interactions and size segregation in drying colloidal blends and provides a valuable tool to control the assembly of different film architectures using an extremely simple method.
Turun yliopiston Tutkimustietojärjestelmän portaali