The use of smart colloidal microgels for advanced applications critically depends on their response kinetics. We use pressure jump small angle neutron scattering with supreme time resolution to study the rapid volume phase transition kinetics of such microgels. Utilizing the pressure induced microphase separation inside the microgels we were able to resolve their collapse and swelling kinetics. While the collapse occurs on a time scale of 10 ms, the particle swelling turned out to be much faster. Photon correlation spectroscopy and static small angle neutron scattering unambiguously show, that the much slower collapse can be associated with the complex particle architecture exhibiting a loosely-crosslinked outer region and a denser inner core region. These insights into the kinetics of stimuli-responsive materials are of high relevance for their applications as nano-actuators, sensors or drug carriers. Moreover, the used refined pressure jump small angle neutron scattering technique is of broad interest for soft matter studies.

Significance: Some soft matter systems behave similarly and some differently. Understanding this is one of the significant challenges in the field. For example, while the splay and bend elastic constants for thermotropic and lyotropic nematic liquid crystals are similar, the twist elastic constant is nearly an order of magnitude smaller in lyotropic nematics. Unfortunately, complete elastic data on lyotropic nematics are restricted to one polymer and two chromonic systems, omitting the most common and highly studied lyotropic surfactant systems. This article reports that a surfactant system of disk-like micelles also possesses an extremely small twist elastic constant, demonstrating that this property is general for lyotropic liquid crystals. The reason likely stems from the higher flexibility of molecular assemblies compared to molecules.

The bending rigidity of surfactant membranes in novel bicontinuous CO₂-microemulsions of the type H₂O/NaCl–scCO₂–Zonyl FSH/Zonyl FSN 100 was determined using both high pressure small angle neutron scattering and neutron-spin echo spectroscopy. As an important result it was found, that the stiffness of the membrane increases solely by an increase of the pressure.

The rapid advancement of covalent organic frameworks (COFs) in recent years has firmly established them as a new class of molecularly precise and highly tuneable porous materials. However, compared to other porous materials, such as zeolites and metal‐organic frameworks, the successful integration of hierarchical porosity into COFs remains largely unexplored. The challenge lies in identifying appropriate synthetic methods to introduce secondary pores without compromising the intrinsic structural porosity of COFs. In this study, a template‐induced synthetic methodology is realized to facilitate the construction of hierarchically porous COFs (hCOFs). This novel approach utilizes commercially available zinc oxide nanoparticles as a hard template, enabling to increase the total pore volume of a series of β ‐ketoenamine‐linked COFs as well as an imine‐based COF while preserving their surface areas. In addition to transmission electron microscopy and gas adsorption analyses, small‐angle X‐ray scattering and pulsed field gradient nuclear magnetic resonance techniques are employed to investigate the hierarchical porosity and diffusivity of guest molecules within hCOFs. This study demonstrates that the hierarchically porous nature of hCOFs significantly reduces diffusion limitations, thus leading to simultaneous enhancements in adsorption capacity, diffusivity, and catalytic performance.