Dynamics of soft nanoparticle suspensions at hard X-ray FEL sources below the radiation-damage threshold

IUCrJ

Lehmkhler, F.¹  Sheyfer, D.²  Roseker, W.³  Valerio, J.⁴ 

[1] Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany;Institute of Physical Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany;Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan;The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, 22761 Hamburg, Germany

关键词: XPCS;    FEL;    PNIPAM NANOPARTICLES;    SACLA;    RADIATION-DAMAGE THRESHOLD;    SOFT-MATTER MATERIALS;   

DOI  :  10.1107/S2052252518013696

学科分类：数学（综合）

来源: International Union of Crystallography

【 摘 要 】

The application of X-ray photon correlation spectroscopy (XPCS) at free-electron laser (FEL) facilities enables, for the first time, the study of dynamics on a (sub-)nanometre scale in an unreached time range between femtoseconds and seconds. For soft-matter materials, radiation damage is a major limitation when going beyond single-shot applications. Here, an XPCS study is presented at a hard X-ray FEL on radiation-sensitive polymeric poly(N-isopropylacrylamide) (PNIPAM) nanoparticles. The dynamics of aqueous suspensions of densely packed silica-PNIPAM core-shell particles and a PNIPAM nanogel below the radiation-damage threshold are determined. The XPCS data indicate non-diffusive behaviour, suggesting ballistic and stress-dominated heterogeneous particle motions. These results demonstrate the feasibility of XPCS experiments on radiation-sensitive soft-matter materials at FEL sources and pave the way for future applications at MHz repetition rates as well as ultrafast modes using split-pulse devices.

【 授权许可】

CC BY