Self-division is one of the most common phenomena in living systems and one of the most important properties of life driven by internal mechanisms of cells. Design and engineering of synthetic cells from abiotic components can recreate a life-like function thus contributing to the understanding of the origin of life. Existing methods to induce the self-division of vesicles require external and non-autonomous triggers (temperature change and the addition of membrane precursors). Here we show that pHresponsive giant unilamellar vesicles on the micrometer scale can undergo self-division triggered by an internal autonomous chemical stimulus driven by an enzymatic (urea-urease) reaction coupled to a cross-membrane transport of the substrate, urea. The bilayer of the artificial cells is composed of a mixture of phospholipids (POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine) and oleic acid molecules. The enzymatic reaction increases the pH in the lumen of the vesicles, which concomitantly changes the protonation state of the oleic acid in the inner leaflet of the bilayer causing the removal of the membrane building blocks into the lumen of the vesicles thus decreasing the inner membrane area with respect to the outer one. This process coupled to the osmotic stress (responsible for the volume loss of the vesicles) leads to the division of a mother vesicle into two smaller daughter vesicles. These two processes must act in synergy; none of them alone can induce the division. Overall, our self-dividing system represents a step forward in the design and engineering of a complex autonomous model of synthetic cells. † Electronic supplementary information (ESI) available: Description of the chemical model for the conned urea-urease enzymatic reaction. Descriptions of molecular dynamics simulations and lm balance experiments. Description of videos (Videos S1-S3). Supporting Tables S1, S2 and Fig. S1-S8. See

Highlights • Sol-gel synthesis of mesoporous titania coatings with different pore structures • Dye association in pores depends on the pore sizes and pH of dye solution • Dye association influences the photodegradation process • Monomers show higher photodegradation rates than associated dye molecules

IntroductionPorous silica sol-gel coatings with improved light transmittance (anti-reflective coating = AR) are increasingly popular in various research areas and applications. One of their most important basic requirements is that they maintain their optical stability during the time of their utilization. Attaining sustainable long-lasting porous thin films with AR properties is a major challenge, especially in lighting technologies and in related applications, for instance solar energy conversion [1]. There are numerous requirements in order to avoid the porous system filling with pollutants from the air or the aging process during the utilization (collapsing of structure).Anti-reflective coatings can be single-, double-, or multilayers with gradient or constant refractive index, using coatings or surface texturing on the target surface. Antireflective coatings can be fabricated with nanophysical (chemical vapour deposition, etching, lithography) or with nanochemical methods (solgel process, etc.) [2][3][4].Sol-gel process is one of the commonly used wet chemical methods to prepare AR coatings. The sol-gel techniques are relatively low-cost, the reaction conditions are mild, and moreover the composition and structure of coatings can be easily controlled. The first step of the preparation is the hydrolysis of a suitable silane compound (e.g. alkoxy-silane) in aqueous or alcoholic medium which can be initiated by base or acid catalysis. The hydrolysis followed by polycondensation reaction results in the formation of colloidal particles, macromolecules and/or microphases (precursor sol or solution). Mainly microphases form in case of base catalysis (referred as base catalyzed silica-particles or layers) while using acid catalysis (referred to as acid catalyzed system) polysiloxane chains form in the precursor solution. Deposition of precursor sol onto a solid substrate by dip-coating (or spin-coating process, etc.) results in a thin liquid film on the solid surface, and after drying and/or suitable heat treatment the sol-gel coating is acquired. Mesoporous coatings can be prepared by depositing microphases (the deposited layer will contain several voids among the particles) or by using micellar templates to form the pore system. Strengthening the sol-gel network by post-treatments

One of the main approaches for contact angle determination using sessile drops with a missing apex (e.g., because of the presence of the needle tip) is the polynomial drop-profile fitting method. The major disadvantage of this fitting procedure is that the derived contact angle is highly sensitive to the polynomial order and the number of pixels involved in the actual fit. In the present work, an easily implementable method is introduced to effectively tackle these drawbacks. Instead of fitting the drop-profile itself, the polynomial fitting is applied to the difference between the drop profile and the circumcircle, independently for both sides of the drop. The derivative value of this difference at the contact point is used to correct the slope obtained analytically from the circumcircle. It is shown that this approach allows the robust determination of the contact angle with high (≤0.6°) accuracy in a straightforward manner, and the results are not affected by the actual contact angle, drop volume, or the resolution of the captured image. Validation of this new approach is also given in the contact angle range of 20°–150° by comparing the results to the values calculated by the Young–Laplace fit.

BORBÁLA TEGZE a , EMŐKE ALBERT a , BOGLÁRKA DIKÓ a , JÁNOS MADARÁSZ b , GYÖRGY SÁFRÁN c , ZOLTÁN HÓRVÖLGYI a, * ABSTRACT. Mesoporous TiO2 coatings were prepared by sol-gel dipcoating method on glass and SiO2 coated glass substrates. They were modified with silver by two different methods: impregnation of as-prepared coatings in AgNO3 aqueous solution; coating deposition from precursor sols containing AgNO3. Transmittance spectra, refractive index, layer thickness and porosity were determined by UV-Vis spectroscopy. Crystallinity of the samples was characterized by XRD, and the morphology and structure by HR-TEM. Photoinduced wettability conversion of the samples was studied, and it was found that the presence of the SiO2 barrier layer and the silver content had significant effect on the wetting behaviour. The photoactivity and reusability of the samples were investigated with methyl orange dye degradation under ultraviolet (UV) irradiation. TiO2 coatings impregnated in 1M AgNO3 solution were found to be the most stable photocatalyst system.