Water-Based Dual-Cross-Linked Polymer Binders for High-Energy-Density Lithium-Sulfur Batteries.

High-mass-loading electrodes with long-term stability have long been a great challenge for lithium-sulfur batteries (LSBs), since the conventional binders are unable to cope with the shuttling of lithium polysulfides and the structural damage in an electrode. Here, a novel water-based polymer, polyphosphate acid cross-linked chitosan ethylamide carbamide (PACEC), is developed as a binder to construct high-energy-density sulfur cathode and flexible LSBs. With a dual-cross-linked network, the PACEC shows excellent affinity with lithium polysulfides to relieve the shuttle effect and robust mechanical properties to stabilize the electrode.

A general approach to mechanism in multiproduct reactions: product-specific intermolecular kinetic isotope effects.

Here we report a general method for the measurement of (13)C kinetic isotope effects at natural abundance for reactions that yield two or more products concurrently. We use, as an example, a recently reported Co-catalyzed reaction between cyclopentene and 1-phenyl-1-propyne. High-precision intermolecular (13)C isotope effects are reported for both the formal [2+2] cycloaddition (major) and Alder-ene (minor) reaction products.

A near-infrared mechano responsive polymer system.

A new type of crosslinked polyarylamide based film with a fibrillar morphology that is photomechanically responsive has been created. Without any additive or need of pre-alignment, these films can actuate under NIR stimulation. By constructing the photoresponsive film on top of a piezoelectric poly(vinylidene difluoride) film, electrical energy can be generated under NIR excitation.

Carbon nanotubes promote neuron differentiation from human embryonic stem cells.

Human embryonic stem cells (hESCs) hold great promise for regenerative medicine and transplantation therapy due to their self-renewal and pluripotent properties. We report that 2D thin film scaffolds composed of biocompatible polymer grafted carbon nanotubes (CNTs), can selectively differentiate human embryonic stem cells into neuron cells while maintaining excellent cell viability. According to fluorescence image analysis, neuron differentiation efficiency of poly(acrylic acid) grafted CNT thin films is significant greater than that on poly(acrylic acid) thin films.