Publications by authors named "T Hellweg"

This work investigates the conversion of bicelles into larger sheets or closed vesicles upon dilution and temperature increase for a system composed of the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and the saponin aescin. Due to its peculiar amphiphilic character, aescin is able to decompose DMPC bilayers into smaller, rim-stabilized bicelles. Aspects of the transition process are analyzed in an aescin content- and temperature-dependent manner by photon correlation spectroscopy (PCS), turbidimetry and small-angle neutron scattering (SANS).

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A confined bicontinuous CE-DO--octane microemulsion is studied using neutron spin echo spectroscopy (NSE). Controlled pore glasses serve as confining matrices with pore diameters ranging from 24 to 112 nm. Firstly, the microemulsion in bulk is investigated by NSE and dynamic light scattering, which allows the determination of the unperturbed collective dynamics as well as the observation of the undulation of the surfactant film.

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We use small-angle neutron scattering (SANS) to investigate the structure and phase behavior of a complex fluid within meso- and macroporous matrices. Specifically, bicontinuous microemulsions of the temperature-dependent ternary system CE-water--octane are investigated in controlled pore glass (CPG) membranes with nominal pore diameters of 10 nm, 20 nm, 50 nm, and 100 nm. The scattering data were analyzed using the Teubner-Strey model and a multiphase generalization of clipped Gaussian-field models.

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Microplastic pollution and the urgent need for sustainable agriculture have raised interest in developing degradable carriers for controlled agrochemical release. Porous polymeric particles are particularly promising due to their unique release profiles compared to solid or core-shell carriers. However, creating degradable, mesoporous (2-50 nm) microparticles is challenging, and their potential for agrochemical delivery is largely unexplored.

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Disc-like lipid nanoparticles stabilized by saponin biosurfactants display fascinating properties, including their temperature-driven re-organization. β-Aescin, a saponin from seed extract of the horse chestnut tree, shows strong interactions with lipid membranes and has gained interest due to its beneficial therapeutic implications as well as its ability to decompose continuous lipid membranes into size-tuneable discoidal nanoparticles. Here, we characterize lipid nanoparticles formed by aescin and the phospholipid 1,2-dimyristoyl-sn-glycero-3-phosphocholine.

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