Accurate calibration and control of relative humidity close to 100% by X-raying a DOPC multilayer
- Univ. of California, San Diego, CA (United States). Dept. of of Physics
- Northern Illinois Univ., DeKalb, IL (United States). Dept. of Physics
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Carnegie Mellon Univ., Pittsburgh, PA (United States). Dept. of Physics
Here in this study, we have designed a compact sample chamber that can achieve accurate and continuous control of the relative humidity (RH) in the vicinity of 100%. A 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) multilayer can be used as a humidity sensor by measuring its inter-layer repeat distance (d-spacing) via X-ray diffraction. We convert from DOPC d-spacing to RH according to a theory given in the literature and previously measured data of DOPC multilamellar vesicles in polyvinylpyrrolidone (PVP) solutions. This curve can be used for calibration of RH close to 100%, a regime where conventional sensors do not have sufficient accuracy. We demonstrate that this control method can provide RH accuracies of 0.1 to 0.01%, which is a factor of 10–100 improvement compared to existing methods of humidity control. Our method provides fine tuning capability of RH continuously for a single sample, whereas the PVP solution method requires new samples to be made for each PVP concentration. The use of this cell also potentially removes the need for an X-ray or neutron beam to pass through bulk water if one wishes to work close to biologically relevant conditions of nearly 100% RH.
- Research Organization:
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- Grant/Contract Number:
- AC02-06CH11357; FG02-04ER46173; R01GM44976
- OSTI ID:
- 1280872
- Journal Information:
- Physical Chemistry Chemical Physics. PCCP, Vol. 17, Issue 5; ISSN 1463-9076
- Publisher:
- Royal Society of ChemistryCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Structure of lipid multilayers via drop casting of aqueous liposome dispersions
|
journal | January 2016 |
Similar Records
Effect of Melatonin and Cholesterol on the Structure of DOPC and DPPC Membranes
Temperature dependence of the structural dimensions of the inverted hexagonal (H sub II ) phase of phosphatidylethanolamine-containing membranes