Keywords: metal-organic frameworks • cellulose nanocrystals • aerogels • water purification • porous materialsThis work overcomes the longstanding challenge of processing metal-organic framework (MOF) powders into a convenient and tailorable form by entrapping them within a cellulose nanocrystal (CNC) aerogel. MOFs are a new class of porous materials, assembled from metal ions or ion clusters bridged by organic ligands. Since the pioneering work on MOF-5 reported by Yaghi and co-workers, [1] MOFs have received great attention due to their large surface area and porosity, high thermal stability, and tunable pore structure. MOFs have shown great potential in various applications including gas separation [2] and storage, [3] chemical sensing, [4] catalysis, [5] and so on. Designing and preparing new MOFs, [6] post-modification of existing MOFs, [7] and fabrication of MOFs into different structures [8] are currently of great interest.However, due to the crystalline nature of MOFs, they are most commonly found in powder form and their processability and handling remain a significant challenge. [9] Integrating MOFs onto or within various substrates to produce a shapeable, cost-efficient, and chemically inert product is one way to expand the potential applications of these functional materials.The deposition and growth of MOF particles on substrates has become a highly researched area but is severely constrained by the physical and chemical requirements of the substrate and gives materials with limited functionality. [10] Usually surface modifications are needed in Submitted to 2 order to increase the compatibility between MOFs and substrates, and while different methods to grow MOFs exist, including solvothermal, [11] secondary, [12] layer by layer growth, [13] and electrochemical deposition, [14] the substrates have to be stable during the process or restricted synthetic conditions must be employed. [15] Incorporation of MOF particles onto polymer or fiber substrates (of both synthetic [16] and natural origin [17] ), by blending, deposition or in situ growth, has been demonstrated. However, while these approaches overcome some of the disadvantages of preparing MOF-only materials or planar MOF films, most examples reported to date are either limited by low MOF loadings or reduced flexibility. [16b, 18] One alternative approach used to avoid processing or depositing MOFs is to produce metal organic framework gels (MOGs) which are high surface area MOF-like materials but they generally lack the ordered crystal lattice and desired physical properties of MOFs.[19]Nanocellulose shows great promise for use as a supporting substrate [20] or templating material [21] , especially in the form of cellulose aerogels and foams, because of its high strength, light weight, low cost, non-toxicity and its ability to be processed easily in water. [22] Cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial cellulose are the most common types of nanocellulose which are now being produced with con...

No abstract

The silane self-assembled monolayer (SAM) modification of a SiO2 gate dielectric surface improved the molecular ordering of organic channel semiconductor in organic thin-film transistors (OTFTs), leading to a significant improvement in transistor performance. Mobility of up to 0.18cm2∕Vs (current on∕off ratio of 107) was obtained for OTFTs with a liquid-crystalline polythiophene semiconductor built on an octyltrichlorosilane-modified SiO2 gate dielectric layer, a 450 times improvement over those built on a nonmodified dielectric layer. The mobility enhancement was attributed to the edge-on orientation of the polythiophene molecules induced by the silane SAM layer as deduced from the crystal domain structures in the atomic force microscopic images.

Air-conditioning" textiles with thermal-or moisture-managing functions are of high interest for not only improving human comfort but also reducing energy consumption. However, making the textile sensitive to the surrounding environment and exhibit adaptive thermal/moisture management still remains a great challenge. Herein, a double-sided synergetic Janus textile is developed, featuring reversible diode-like water transportation and adjustable thermal convection upon temperature change. The incorporated responsive polymer networks with inverse transitions on the opposite sides provide synergistic surface energy gradients and capillary gradients that generate drying and cooling effects (with 50% faster water evaporation and 1.2-2.3 °C cooler than with cotton fabric) in hot weather while offering thermal preservation (120 s longer needed to be cooled down and maximumly 3.3 °C warmer than with cotton fabric) in a cold environment. This method could provide ideas for the development of more adaptive textiles and clothing to address maximum personal comfort in demanding situations.

A series of well-controlled polystyrene-b-poly(n-butyl acrylate)-b-polystyrene triblock copolymers were prepared by emulsion polymerization with a carefully designed amphiphilic macroRAFT (reversible addition-fragmentation chain transfer) agent. The triblock copolymers were produced within four hours and only a few percent of dead chains were estimated. Tensile strength of the materials was a function of composition only and it increased linearly with polystyrene composition up to 50 wt %. The ultimate tensile strength reached 10 MPa with an elongation at break of 500% at the polystyrene composition of 40-50 wt %.