Deep eutectic solvents (DES) are a category of a new class of solvents that can overcome some of the main drawbacks of typical solvents and ionic liquids (ILs). DES have been widely investigated and applied by the research community in several applications since their invention. Over the past years, the use of DES has been directed to the production of new materials and items for new products and processes. This is the case for the implementation of DES in various fields of chemical engineering directed to separations. DES have been very recently initiated to be combined into membranes for membrane processes. In this regard, this Review timely elucidates the current progress in utilizing this new generation of solvents in membrane preparation. In this work, different techniques, methods, and strategies for incorporating DES into polymer membranes for different concepts of membranes according to the final application have been reviewed. Particular emphasis has been devoted to the most relevant development works and results. After the current literature was analyzed, the main challenges and possibilities of DES in membranes were declared.

Glassy carbon electrodes coated with a film of electrodeposited cobalt and nickel hydroxides were prepared in order to determine its activity to the 2,4,6-trichlorophenol (TCP) oxidation. The modified electrodes were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), X-ray photoelectron spectroscopy and Scan Electron Microscopy (SEM) with Energy Dispersive X-ray Spectroscopy (EDS). The results indicate that both hydroxides are homogeneously distributed in the electrode surface. From the viewpoint of electrochemical oxidation of TCP, the presence of cobalt and nickel hydroxides on the electrode surface (i) promotes a more complete oxidation of TCP and (ii) decreases the fouling of the electrode surface in comparison with GC and GC modified with Ni or Co separately. Keywords:Modified electrodes, (Ni-Co) hydroxides, chlorophenol oxidation e-mail: soledad.ureta@usach.cl 1.-INTRODUCTIONWaste from domestic, agricultural and industrial activities such as cellulose treatment and the manufacturing of plastics, adhesives and petrochemicals may pollute watercourses [1]. The widely used halogenated compounds are not amenable to biological degradation, and can accumulate in living organisms, this being the reason why they are used as wood preservatives, antibacterial agents, fungicides, insecticides and herbicides [2,3].Au and Pt show high catalytic activity for the electrooxidation of chlorophenols (CP) over short times, but they are quickly fouled up by small oligomers, generated by the coupling of two phenoxy radicals or by reaction of a radical with unreacted CP molecules [4,5]. Electrodes modified with redox mediators could increase the activity and specificity for a given reaction and avoid fouling [6]. So, glassy carbon (GC) electrodes modified with Co(II) phthalocyanine (CoPc) show higher currents and less fouling in the oxidation of 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP) in 1 M NaOH [7]. Also Alatorre et al. [8] found that GC electrodes modified with electropolymerized nickel complexes showed less fouling in the oxidation of 4-CP and 4-nitrophenol in 1 M NaOH. Our laboratory has some experience in this field [4,5,9,10,11]. The goal is to decrease the oligomerization rate and to promote full oxidation of the phenolic compound.The redox mediator activity in alkaline media of electrodes modified with Ni(II) compounds is due to the quasi reversible properties of the Ni(III)/Ni(II) process [9,10,11],which may be represented as follows [12]:Actually nickel hydroxide can have more than one stable structure [13,14,15]. Van der Ven et al. [16] reported the formation of two types of nickel hydroxide, α -and β-Ni(OH) 2 , and two kinds of nickel oxyhydroxides, α -and γ-NiOOH, which, due to their different structures and degrees of hydration, have different electrochemical properties.Other hydroxide, Co(OH) 2 , has been widely used as an additive to Ni(OH) 2 in order to improve alkaline secondary batteries [17,18,19], these improvements being attributed to an increase of bot...

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