Nanoscale Control of the Surface Functionality of Polymeric 2D Materials

Typically, 2D nanosheets have a homogeneous surface, making them a major challenge to structure. This study proposes a novel concept of 2D organic nanosheets with a heterogeneously functionalized surface. This work achieves this by consecutively crystallizing two precisely synthesized polymers with different functional groups in the polymer backbone in a two-step process. First, the core platelet is formed and then the second polymer is crystallized around it. As a result, the central area of the platelets has a different surface functionality than the periphery. This concept offers two advantages: the resulting polymeric 2D platelets are stable in dispersion, which simplifies further processing and makes both crystal surfaces accessible for subsequent functionalization. Additionally, a wide variety of polymers can be used, making the process and the choice of surface functionalization very flexible.</p

An outer membrane‐inspired polymer coating protects and endows Escherichia coli with novel functionalities

A bio‐inspired membrane made of Pluronic L‐121 is produced around Escherichia coli thanks to the simple co‐extrusion of bacteria and polymer vesicles. The block copolymer‐coated bacteria can withstand various harsh shocks, for example, temperature, pressure, osmolarity, and chemical agents. The polymer membrane also makes the bacteria resistant to enzymatic digestion and enables them to degrade toxic compounds, improving their performance as whole‐cell biocatalysts. Moreover, the polymer membrane acts as an anchor layer for the surface modification of the bacteria. Being decorated with α‐amylase or lysozyme, the cells are endowed with the ability to digest starch or self‐predatory bacteria are created. Thus, without any genetic engineering, the phenotype of encapsulated bacteria is changed as they become sturdier and gain novel metabolic functionalities

Controlling the crystal structure of precisely spaced polyethylene-like polyphosphoesters

Understanding polymer crystallization is important for polyethylene-like materials. A small fraction of monomers with functional groups within the polyethylene chain can act as crystallization “defects”. Such defects can be used to control the crystallization behavior in bulk and to generate functional anisotropic polymer crystals if crystallized from a dilute solution. Due to their geometry, phosphate groups cannot be incorporated in the polyethylene lamellae and thus control chain folding and crystal morphology. Herein, the synthesis and crystallization behavior for three different long-chain polyphosphates with a precise spacing of 20, 30, and 40 CH2-groups between each phosphate group are reported. Monomers were prepared by esterification of ethyl dichlorophosphate with respective tailor-made unsaturated alcohols. Acyclic diene metathesis (ADMET) polymerization and subsequent hydrogenation were used to receive polyethylene-like polyphosphoesters with molecular weights up 23 100 g mol−1. Polymer crystallization was studied from the melt and dilute solution. Samples were characterized by differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), wide-angle X-ray scattering (WAXS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). A change in crystal structure from pseudo-hexagonal to orthorhombic was observed from the “C20” to the “C40” polymer. Melting points and lamellar thicknesses increased with the length of the aliphatic spacer from 51 °C (“C20”) to 62 °C (“C30”) and 91 °C (“C40”). Values for the long periods in bulk (3.1 nm for C20, 4.8 nm for C30, and 7.2 nm for C40) obtained by SAXS and TEM are in qualitative agreement. The thickness of the crystalline part obtained by AFM and TEM increased from about 1.0 nm (C20) to 2.0 nm (C30) to 2.9 nm (C40). Our systematic library of long-chain polyphosphates will allow designing anisotropic polymer colloids by crystallization from solution as functional and versatile colloid platform

Social crisis: reflection on the economic, social and educational alternatives from a gender perspective

Colección ReSed. Es un artículo de ReSed Nº 3, perteneciente al monográfico Crisis Social, Educación y Desarrollo Profesional. Coordinación del Monográfico: Dra. Montserrat Vargas Vergara Dirección de ReSed: Dra. A-Beatriz Pérez-GonzálezEn el presente artículo hacemos una reflexión sobre cómo la actual crisis financiera plantea una crisis de valores, que nos lleva a la necesidad de reorganización en lo económico, social y educativo. La interpretación del problema la hacemos desde un posicionamiento de estudio de género, donde veremos cómo el feminismo traza alternativas viables. Las perspectivas de la economía feminista o economía del bien común son algunas de las alternativas que vamos a reflejar, al mismo tiempo que describimos una realidad condicionada por el género, no siempre asumida por los gobernantes. La propuesta que surge de esta reflexión está basada en el cuidado equilibrado de todos los miembros de la sociedad, promoviendo una educación igualitaria y más libre entre los géneros; nuevos caminos que se hacen necesarios para construir una sociedad más equitativa y sostenible y que favorezcan el desarrollo personal, social y laboral de todos sus miembros

An outer membrane-inspired polymer coating protects and endows E. coli with novel functionalities

A bio-inspired membrane made of Pluronic® L-121 is produced around E. coli thanks to the simple co-extrusion of bacteria and polymer vesicles. The block copolymer-coated bacteria can withstand a variety of harsh shocks, e.g. temperature, pressure, osmolarity and chemical agents. The polymer membrane also makes the bacteria resistant against enzymatic digestion and enables them to degrade toxic compounds, improving their performance as whole-cell biocatalysts. Moreover, the polymer membrane acts as a new region for surface modification. Being decorated with α-amylase or lysozyme, the cells are endowed with the ability to digest starch, or self-predatory bacteria are created. Thus, without any genetic engineering, the phenotype of encapsulated bacteria is changed, as they become sturdier and gain novel metabolic functionalities

Synthesis and characterization of bentonite/iron nanoparticles and their application as adsorbent of cobalt ions

This study reports the synthesis and characterization of iron nanoparticles in the presence of K10 bentonite. Introducing K10 during synthesis of iron nanoparticles resulted in a partial decrease in the aggregation of the nanoparticles. The dispersed nanoparticles showed a typical core–shell structure and were predominantly within the 10–60 nm size range. The composite adsorbent was tested for the removal of Co2+ ions in aqueous solution at various contact times, concentrations, pH, and repetitive loadings. The rate of adsorption was evaluated using first and second order rate equations. The adsorption was described by the Freundlich model. The adsorbent showed effective removal after re-use and the adsorption increased with increasing initial pH.Izmir Institute of Technolog