An innovative procedure for positioning a monolayer of hydrophilic metal organic framework (MOF) MIL-101(Cr) (MIL, Materials of Institute Lavoisier) nanoparticles (NPs) in thin-film nanocomposite (TFN) membranes has been implemented by transferring a Langmuir-Schaefer (LS) film of the MOF in between the polyamide thin layer at the top and the cross-linked asymmetric polyimide (P84) support at the bottom. The presence and layout of the LS-MIL-101(Cr) monolayer in the TFN membrane was confirmed by scanning transmission electron microscopy imaging with a high-angle annular dark-field detector images and X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy, electron energy loss spectroscopy, and atomic force microscopy analyses. This methodology requires the smallest amount of MOF reported to date, 3.8 μg cm, and promotes the formation of a defect-free ultrathin MOF film. Although conventional TFN membranes tend to show MOF agglomerates that could contribute to the formation of unselective defects, LS-TFN membranes, characterized by a homogeneous and continuous MOF coating, exhibit an optimal membrane performance, without a significant decrease in selectivity. Outstanding methanol permeances, one of the best results reported to date, of 10.1 ± 0.5 L m h bar when filtering sunset yellow and of 9.5 ± 2.1 L m h bar when filtering rose bengal have been achieved in LS-TFN membranes with a rejection higher than 90% in all cases. Methanol permeates through the polyamide and the LS-MIL-101(Cr) monolayer, greatly enhanced by the MOF pore system, in comparison to thin-film composite and conventional TFN membranes (7.5 ± 0.7 and 7.7 ± 1.1 L m h bar when filtering sunset yellow), respectively, in which polyamide areas free of MOF NPs are present.

This work reports the fabrication and characterization of Langmuir-Blodgett films of nanoparticles (size 51 ± 10 nm) of the metal organic framework MIL-101(Cr). LB film characterization by SEM, UV-vis, GIXRD and QCM has shown that the addition of 1 wt.% of behenic acid to MOF dispersion allows obtaining dense monolayers at the airwater interface that can be deposited onto solid substrates of different nature with transfer ratios close to 1. Moreover, a QCM-based setup has been built and used for the first time to measure CO 2 adsorption isotherms at 303 K on MOF LB films, proving that LB films with MOF masses between 1.2 (1 layer) and 2.3 (2 layers) micrograms can be used to obtain accurate adsorption values at 100 kPa, similar to those obtained by conventional adsorption methods that require much larger MOF quantities (tens of milligrams).3

The use of ultrathin films as selective layers in composite membranes offers significant advantages in gas separation for increasing productivity while reducing the membrane size and energy costs. In this contribution, composite membranes have been obtained by the successive deposition of approximately 1 nm thick monolayers of a polymer of intrinsic microporosity (PIM) on top of dense membranes of the ultra-permeable poly[1-(trimethylsilyl)-1-propyne] (PTMSP). The ultrathin PIM films (30 nm in thickness) demonstrate CO permeance up to seven times higher than dense PIM membranes using only 0.04 % of the mass of PIM without a significant decrease in CO /N selectivity.

In this work, the fabrication of ultrathin films containing the metal organic framework (MOF) Fe-MIL-88B-NH 2 by the Langmuir-Blodgett (LB) technique has been explored.MOF crystals of two different sizes (1.5 ± 0.3 and 0.07 ± 0.01 µm) have been synthesized and assembled at the air-liquid interface by the LB method. The effect of the subphase pH and particle size on the film formation process has been studied.Moreover, for the first time, mixed MOF + polymer (a commercial soluble polyimide) LB films containing different MOF loadings have been fabricated. These experiments show that it is possible to obtain ultrathin MOF + polymer films with a controlled MOF density. Furthermore, MOF particles are homogeneously distributed in the polymer matrix, even with very large amounts of MOF (up to 95 wt%). LB films have been incorporated into materials of different nature, including glass and mica substrates and also polymeric membranes, and the modification of water contact angle after LB film deposition has been analyzed.

Polymers in highly confined geometries can display complex morphologies including ordered phases. A basic component of a theoretical analysis of their phase behavior in confined geometries is the knowledge of the number of possible single-chain conformations compatible with the geometrical restrictions and the established crystalline morphology. While the statistical properties of unrestricted self-avoiding random walks (SAWs) both on and off-lattice are very well known, the same is not true for SAWs in confined geometries. The purpose of this contribution is (a) to enumerate the number of SAWs on the simple cubic (SC) and face-centered cubic (FCC) lattices under confinement for moderate SAW lengths, and (b) to obtain an approximate expression for their behavior as a function of chain length, type of lattice, and degree of confinement. This information is an essential requirement for the understanding and prediction of entropy-driven phase transitions of model polymer chains under confinement. In addition, a simple geometric argument is presented that explains, to first order, the dependence of the number of restricted SAWs on the type of SAW origin.

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Nowadays, there is growing increase of plastics use in the world of food industry and medicine. In this context there is a need of, apart from conventional properties of plastics, minimizing growth of harmful microorganisms. In this article new polymer based materials are prepared, characterized and evaluated against their antibacterial action. New materials based on poly(ethylene-co-vinyl acetate) are prepared by solution blow spinning, SBS. Mats of nanocomposites constituted by micrometric fibers are obtained with compositions ranging from 0% to 6% by weight of Cu nanoparticles, CuNp. In order to understand the effect of the CuNp on the E. coli cell adhesion and biofilm formation, morphology, structure, thermal and surface properties of the nanocomposites are studied by several techniques. SBS allows preparing the nanocomposites with quite uniform dispersion of CuNp within the polymer. Neither the presence of CuNp nor the SBS process induce changes in the structure and in the thermo-degradation of EVA40. The presence of CuNp exerts antibacterial effect against the DH5α E. coli. There is a direct action of the CuNp on the extracellular polymeric substances and on the bacterial metabolism. CuNp also affect HaCaT cells growing, delaying the process at higher amounts of Cu but keeping their viability.

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