Journal Article

PUBDB-2021-02211

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Synergistic and Competitive Adsorption of Hydrophilic Nanoparticles and Oil-Soluble Surfactants at the Oil–Water Interface

Smits, J. (First author)Extern* ; Giri, R. P.Extern* ; Shen, C.DESY* ; Mendonça, D.Extern* ; Murphy, B.Extern* ; Huber, P.Extern*DESY* ; Rezwan, K. ; Maas, M. (Corresponding author)Extern*

2021
ACS Publ. Washington, DC

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Please use a persistent id in citations: doi:10.1021/acs.langmuir.1c00559  doi:10.3204/PUBDB-2021-02211

Abstract: Fundamental insights into the interplay and self-assembly of nanoparticles and surface-active agents at the liquid–liquid interface play a pivotal role in understanding the ubiquitous colloidal systems present in our natural surroundings, including foods and aquatic life, and in the industry for emulsion stabilization, drug delivery, or enhanced oil recovery. Moreover, well-controlled model systems for mixed interfacial adsorption of nanoparticles and surfactants allow unprecedented insights into nonideal or contaminated particle-stabilized emulsions. Here, we investigate such a model system composed of hydrophilic, negatively, and positively charged silica nanoparticles and the oil-soluble cationic lipid octadecyl amine with in situ synchrotron-based X-ray reflectometry, which is analyzed and discussed jointly with dynamic interfacial tensiometry. Our results indicate that negatively charged silica nanoparticles only adsorb if the oil–water interface is covered with the positively charged lipid, indicating synergistic adsorption. Conversely, the positively charged nanoparticles readily adsorb on their own, but compete with octadecyl amine and reversibly desorb with increasing concentrations of the lipid. These results further indicate that with competitive adsorption, an electrostatic exclusion zone exists around the adsorbed particles. This prevents the adsorption of lipid molecules in this area, leading to a decreased surface excess concentration of surfactants and unexpectedly high interfacial tension.

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Contributing Institute(s):

1. DOOR-User (DOOR ; HAS-User)
2. Experimentebetreuung PETRA III (FS-PET-D)

Research Program(s):

1. 6G3 - PETRA III (DESY) (POF4-6G3) (POF4-6G3)
2. 633 - Life Sciences – Building Blocks of Life: Structure and Function (POF4-633) (POF4-633)

Experiment(s):

1. PETRA Beamline P08 (PETRA III)

Appears in the scientific report 2021

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Database coverage:
; ; ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF < 5 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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