Temperature response of sucrose palmitate solutions: Role of ratio between monoesters and diesters.

Hypothesis: Aqueous solutions of long-chain water-soluble sucrose ester surfactants exhibit non-trivial response to temperature variations, revealing a peak in viscosity around 40-50 °C. While previous investigations have explored the structures within sucrose stearate systems at various constant temperatures, a comprehensive understanding of the entire temperature dependence and the underlying molecular factors, contributing to this phenomenon is currently missing.

Experiments: Temperature dependent properties and supramolecular structures formed in aqueous solutions of commercial sucrose palmitate were examined using SAXS/WAXS, DSC, optical microscopy, rheological measurements, NMR, and cryo-TEM.

Retropupillary Iris-fixated versus Sutured Scleral-fixated Intraocular Lenses.

To compare the anatomical and functional results and patient satisfaction following retropupillary implantation of Artisan Aphakia iris-fixated intraocular lens (rAAIF) and sutured scleral fixated intraocular lens (SFIOL). We presented a prospective double-arm non-blinded study. Forty-one eyes with acquired aphakia, no age-related macular degeneration, no previous keratoplasty, no combined procedures, no AC reaction (cells, fibrin), normal intraocular pressure, no history of endothelial corneal dystrophy in relatives or fellow eye were included.

Polymorphic phase transitions in triglycerides and their mixtures studied by SAXS/WAXS techniques: In bulk and in emulsions.

Triacylglycerols (TAGs) exhibit a monotropic polymorphism, forming three main polymorphic forms upon crystallization: α, β' and β. The distinct physicochemical properties of these polymorphs, such as melting temperature, subcell lattice structure, mass density, etc., significantly impact the appearance, texture, and long-term stability of a wide range products in the food and cosmetics industries.

Structure of the Hexadecane Rotator Phase: Combination of X-ray Spectra and Molecular Dynamics Simulation.

Rotator phases are rotationally disordered plastic crystals, some of which can form upon freezing of alkane at alkane-water interfaces. Existing X-ray diffraction studies show only partial unit cell information for rotator phases of some alkanes. This includes the rotator phase of -hexadecane, which is a transient metastable phase in pure alkane systems, but shows remarkable stability at interfaces when mediated by a surfactant.

Presbyopia correction with a new Extended Depth of Focus Intraocular Lens.

Extended depth of focus intraocular lenses (EDoF IOLs) offer an expanded number of modalities for simultaneous cataract and presbyopia treatment. The objective of the current study was to assess clinical outcomes with a new mono-EDoF intraocular lens and to analyze the effect of different parameters on postoperative results. The inclusion criteria were defined as uneventful cataract surgery, no history of concomitant ocular disease, implantation of ZOE Primus-HD lens.

Correction: Spontaneous particle desorption and "Gorgon" drop formation from particle-armored oil drops upon cooling.

Correction for 'Spontaneous particle desorption and "Gorgon" drop formation from particle-armored oil drops upon cooling' by Diana Cholakova et al., Soft Matter, 2020, 16, 2480-2496, DOI: 10.1039/C9SM02354B.

Rotator phases in hexadecane emulsion drops revealed by X-ray synchrotron techniques.

Hypothesis: Micrometer sized alkane-in-water emulsion drops, stabilized by appropriate long-chain surfactants, spontaneously break symmetry upon cooling and transform consecutively into series of regular shapes (Denkov et al., Nature 2015, 528, 392). Two mechanisms were proposed to explain this phenomenon of drop "self-shaping".

Cold-Burst Method for Nanoparticle Formation with Natural Triglyceride Oils.

The preparation of nanoemulsions of triglyceride oils in water usually requires high mechanical energy and sophisticated equipment. Recently, we showed that α-to-β (viz., gel-to-crystal) phase transition, observed with most lipid substances (triglycerides, diglycerides, phospholipids, alkanes, etc.

Nanopore and Nanoparticle Formation with Lipids Undergoing Polymorphic Phase Transitions.

We describe several unexpected phenomena, caused by a solid-solid phase transition (gel-to-crystal) typical for all main classes of lipid substances: phospholipids, triglycerides, diglycerides, alkanes, . We discovered that this transition leads to spontaneous formation of a network of nanopores, spreading across the entire lipid structure. These nanopores are spontaneously impregnated (flooded) by water when appropriate surfactants are present, thus fracturing the lipid structure at a nanoscale.

Spontaneous particle desorption and "Gorgon" drop formation from particle-armored oil drops upon cooling.

We study how the phenomenon of drop "self-shaping" (Denkov et al., Nature, 528, 2015, 392), in which oily emulsion drops undergo a spontaneous series of shape transformations upon emulsion cooling, is affected by the presence of adsorbed solid particles, like those used in Pickering emulsion stabilization. Experiments with several types of latex particles, and with added surfactant of low concentration to enable drop self-shaping, revealed several new unexpected phenomena: (1) adsorbed latex particles rearranged into regular hexagonal lattices upon freezing of the surfactant adsorption layer.

Rotator phases in alkane systems: In bulk, surface layers and micro/nano-confinements.

Medium- and long-chain alkanes and their mixtures possess a remarkable physical property - they form intermediate structured phases between their isotropic liquid phase and their fully ordered crystal phase. These intermediate phases are called "rotator phases" or "plastic phases" (soft solids) because the incorporated alkane molecules possess a long-range positional order while preserving certain mobility to rotate, which results in complex visco-plastic rheological behaviour. The current article presents a brief overview of our current understanding of the main phenomena involved in the formation of rotator phases from single alkanes and their mixtures.

Multilayer Formation in Self-Shaping Emulsion Droplets.

In several recent studies, we showed that micrometer-sized oil-in-water emulsion droplets from alkanes, alkenes, alcohols, triglycerides, or mixtures of these components can spontaneously "self-shape" upon cooling into various regular shapes, such as regular polyhedrons, platelets, rods, and fibers ( Denkov , N. , Nature 2015 , 528 , 392 ; Cholakova , D. , Adv.

Mechanisms and Control of Self-Emulsification upon Freezing and Melting of Dispersed Alkane Drops.

Emulsification requires drop breakage and creation of a large interfacial area between immiscible liquid phases. Usually, high-shear or high-pressure emulsification devices that generate heat and increase the emulsion temperature are used to obtain emulsions with micrometer and submicrometer droplets. Recently, we reported a new, efficient procedure of self-emulsification (Tcholakova et al.

"Self-Shaping" of Multicomponent Drops.

In our recent study we showed that single-component emulsion drops, stabilized by proper surfactants, can spontaneously break symmetry and transform into various polygonal shapes during cooling [ Denkov Nature 2015 , 528 , 392 - 395 ]. This process involves the formation of a plastic rotator phase of self-assembled oil molecules beneath the drop surface. The plastic phase spontaneously forms a frame of plastic rods at the oil drop perimeter which supports the polygonal shapes.

Efficient self-emulsification via cooling-heating cycles.

In self-emulsification higher-energy micrometre and sub-micrometre oil droplets are spontaneously produced from larger ones and only a few such methods are known. They usually involve a one-time reduction in oil solubility in the continuous medium via changing temperature or solvents or a phase inversion in which the preferred curvature of the interfacial surfactant layer changes its sign. Here we harness narrow-range temperature cycling to cause repeated breakup of droplets to higher-energy states.

Theory of Shape-Shifting Droplets.

Recent studies of cooled oil emulsion droplets uncovered transformations into a host of flattened shapes with straight edges and sharp corners, driven by a partial phase transition of the bulk liquid phase. Here, we explore theoretically the simplest geometric competition between this phase transition and surface tension in planar polygons and recover the observed sequence of shapes and their statistics in qualitative agreement with experiments. Extending the model to capture some of the three-dimensional structure of the droplets, we analyze the evolution of protrusions sprouting from the vertices of the platelets and the topological transition of a puncturing planar polygon.

On the Mechanism of Drop Self-Shaping in Cooled Emulsions.

Two recent studies (Denkov et al., Nature 2015, 528, 392 and Guttman et al. Proc.

Control of drop shape transformations in cooled emulsions.

The general mechanisms of structure and form generation are the keys to understanding the fundamental processes of morphogenesis in living and non-living systems. In our recent study (Denkov et al., Nature 528 (2015) 392) we showed that micrometer sized n-alkane drops, dispersed in aqueous surfactant solutions, can break symmetry upon cooling and "self-shape" into a series of geometric shapes with complex internal structure.

Self-shaping of oil droplets via the formation of intermediate rotator phases upon cooling.

Revealing the chemical and physical mechanisms underlying symmetry breaking and shape transformations is key to understanding morphogenesis. If we are to synthesize artificial structures with similar control and complexity to biological systems, we need energy- and material-efficient bottom-up processes to create building blocks of various shapes that can further assemble into hierarchical structures. Lithographic top-down processing allows a high level of structural control in microparticle production but at the expense of limited productivity.