Abstract
Hydration forces play a crucial role in a wide range of phenomena in physics, chemistry, and biology. Here, we study the hydration of mica surfaces in contact with various alkali chloride solutions over a wide range of concentrations and pH values. Using atomic force microscopy and molecular dynamics simulations, we demonstrate that hydration forces consist of a superposition of a monotonically decaying and an oscillatory part, each with a unique dependence on the specific type of cation. The monotonic hydration force gradually decreases in strength with decreasing bulk hydration energy, leading to a transition from an overall repulsive (Li + , Na + ) to an attractive (Rb + , Cs + ) force. The oscillatory part, in contrast, displays a binary character, being hardly affected by the presence of strongly hydrated cations (Li + , Na + ), but it becomes completely suppressed in the presence of weakly hydrated cations (Rb + , Cs + ), in agreement with a less pronounced water structure in simulations. For both aspects, K + plays an intermediate role, and decreasing pH follows the trend of increasing Rb + and Cs + concentrations.
| Original language | English |
|---|---|
| Pages (from-to) | 5737-5745 |
| Number of pages | 9 |
| Journal | Langmuir |
| Volume | 35 |
| Issue number | 17 |
| DOIs | |
| Publication status | Published - 30 Apr 2019 |
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Keywords
- UT-Hybrid-D
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Ion-Specific and pH-Dependent Hydration of Mica-Electrolyte Interfaces. / Van Lin, Simone R.; Grotz, Kara K.; Siretanu, Igor; Schwierz, Nadine; Mugele, Frieder.
In: Langmuir, Vol. 35, No. 17, 30.04.2019, p. 5737-5745.Research output: Contribution to journal › Article › Academic › peer-review
TY - JOUR
T1 - Ion-Specific and pH-Dependent Hydration of Mica-Electrolyte Interfaces
AU - Van Lin, Simone R.
AU - Grotz, Kara K.
AU - Siretanu, Igor
AU - Schwierz, Nadine
AU - Mugele, Frieder
N1 - ACS deal
PY - 2019/4/30
Y1 - 2019/4/30
N2 - Hydration forces play a crucial role in a wide range of phenomena in physics, chemistry, and biology. Here, we study the hydration of mica surfaces in contact with various alkali chloride solutions over a wide range of concentrations and pH values. Using atomic force microscopy and molecular dynamics simulations, we demonstrate that hydration forces consist of a superposition of a monotonically decaying and an oscillatory part, each with a unique dependence on the specific type of cation. The monotonic hydration force gradually decreases in strength with decreasing bulk hydration energy, leading to a transition from an overall repulsive (Li + , Na + ) to an attractive (Rb + , Cs + ) force. The oscillatory part, in contrast, displays a binary character, being hardly affected by the presence of strongly hydrated cations (Li + , Na + ), but it becomes completely suppressed in the presence of weakly hydrated cations (Rb + , Cs + ), in agreement with a less pronounced water structure in simulations. For both aspects, K + plays an intermediate role, and decreasing pH follows the trend of increasing Rb + and Cs + concentrations.
AB - Hydration forces play a crucial role in a wide range of phenomena in physics, chemistry, and biology. Here, we study the hydration of mica surfaces in contact with various alkali chloride solutions over a wide range of concentrations and pH values. Using atomic force microscopy and molecular dynamics simulations, we demonstrate that hydration forces consist of a superposition of a monotonically decaying and an oscillatory part, each with a unique dependence on the specific type of cation. The monotonic hydration force gradually decreases in strength with decreasing bulk hydration energy, leading to a transition from an overall repulsive (Li + , Na + ) to an attractive (Rb + , Cs + ) force. The oscillatory part, in contrast, displays a binary character, being hardly affected by the presence of strongly hydrated cations (Li + , Na + ), but it becomes completely suppressed in the presence of weakly hydrated cations (Rb + , Cs + ), in agreement with a less pronounced water structure in simulations. For both aspects, K + plays an intermediate role, and decreasing pH follows the trend of increasing Rb + and Cs + concentrations.
KW - UT-Hybrid-D
UR - http://www.scopus.com/inward/record.url?scp=85065084882&partnerID=8YFLogxK
U2 - 10.1021/acs.langmuir.9b00520
DO - 10.1021/acs.langmuir.9b00520
M3 - Article
C2 - 30974056
AN - SCOPUS:85065084882
VL - 35
SP - 5737
EP - 5745
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 17
ER -