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Block copolymers with a low hydrophilic-to-lipophilic balance form membranes that are highly permeable to hydrophilic molecules. Polymersomes with this type of membrane enable the controllable release of molecules without membrane rupture. However, these polymersomes are difficult to assemble because of their low hydrophobicity. Here, we report a microfluidic approach to the production of these polymersomes using double-emulsion drops with ultrathin shells as templates. The small thickness of the middle oil phase enables the attraction of the hydrophobic blocks of the polymers adsorbed at each of the oil/water interfaces of the double emulsions; this results in the dewetting of the oil from the surface of the innermost water drops of the double emulsions and the ultimate formation of the polymersome. This approach to polymersome fabrication enables control of the vesicle size and results in the efficient encapsulation of hydrophilic ingredients that can be released through the polymer membrane without membrane rupture. We apply our approach to the fabrication of Pluronic L121 vesicles and characterize the permeability of their membranes. Furthermore, we show that membrane permeability can be tuned by blending different Pluronic polymers. Our work thus describes a route to producing Pluronic vesicles that are useful for the controlled release of hydrophilic ingredients.

a b s t r a c tThis paper reports the p-nitrophenol (PNP) removal from aqueous solutions by adsorption onto active carbons (ACs). Nine ACs were prepared from acid-precipitated eucalyptus kraft lignin following a twostep process consisting in CO 2 partial gasification (750-850• C) after carbonization (350-800 • C) in N 2 atmosphere. The amount adsorbed ranged from 1 to 4.4 mmol/g, and it is related to the initial concentration of adsorbate, temperature, pH, burn off of the activated carbons, and contact time. The equilibrium results were fitted by the Temkin, Dubinin-Radushkevich, and Guggenheim-Anderson-de Boer equations. The main thermodynamic magnitudes were estimated as well, and their values indicated that the adsorption processes were spontaneous and exothermic. The kinetic study showed that the processes are of apparent second order related to the concentrations of the empty active sites on the ACs surface. The values of the effective diffusivities have been calculated and they have suggested that the internal diffusion controls the net mass transfer. The results obtained in the present work can be for the benefit of the preparation of new adsorbents, as well as the primary design of the adsorption equipment with separation or environmental purposes.

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