Polymer Nanosheets from Supramolecular Assemblies of Conjugated Linoleic Acid-High Surface Area Adsorbents from Renewable Materials

Research progress in the preparation of mesophase pitch from fluid catalytic cracking slurry

For the preparation of high-performance pitch-based carbon fibers and other carbon materials, mesophase pitch serves as a high-quality precursor. Since FCC (Fluid Catalytic Cracking) oil slurry is abundant in aromatic hydrocarbons and saturated hydrocarbons (about 95% in total), it has become an ideal choice for developing new carbon material products. This paper details the research progress of preparing mesophase asphalt with FCC oil slurry as a raw material from perspectives including the preparation method of synthesizing mesophase asphalt from FCC oil slurry, the impact factors of the formation process of mesophase asphalt and the industrial application of mesophase asphalt.

Self-Assembly of Functional Protein Nanosheets from Thermoresponsive Bolaamphiphiles

Nanosheets are two-dimensional materials, less than 100 nm thick, that can be used for separations, biosensing, and biocatalysis. Nanosheets can be made from inorganic and organic materials such as graphene, polymers, and proteins. Here, we report the self-assembly of nanosheets under aqueous conditions from functional proteins. The nanosheets are synthesized from two fusion proteins held together by high-affinity interactions of two leucine zippers to form bolaamphiphiles. The hydrophobic domain, Z_R-ELP-Z_R, contains the thermoresponsive elastin-like peptide (ELP) flanked by arginine-rich leucine zippers (Z_R), each of which binds the hydrophilic fusion protein, globule-Z_E, via the glutamate-rich leucine zipper (Z_E) fused to a functional, globular protein. Nanosheets form when the proteins are mixed at 4 °C in aqueous solutions and then heated to 25 °C as the container is rotated end-over-end causing expansion and contraction of the air-water interface. The nanosheets are robust with respect to the choice of globular protein and can incorporate small fluorescent proteins that are less than 30 kDa as well as large enzymes, such as 80 kDa malate synthase G. Upon incorporation into nanosheets, enzymes retain more than 70% of their original activity, demonstrating the potential of protein nanosheets to be used for biosensing or biocatalytic applications.

Crystallization Induced Self-Assembly: A Strategy to Achieve Ultra-Small Domain Sizes

Achieving self-assembled nanostructures with ultra-small feature sizes (e. g., below 5 nm) is an important prerequisite for the development of block copolymer lithography. In this work, the preparation and self-assembly of a series of giant molecules composed of vinyl polyhedral oligomeric silsesquioxane (VPOSS) tethered with monodispersed oligo(L-lactide) chains are presented. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) results demonstrate that ultra-small domain sizes (down to 3 nm) of phase separated lamellar morphology are achieved in bulk, driven by the strong tendency and fast kinetics for crystallization of VPOSS moieties. Moreover, upon gamma ray radiation, VPOSS cages in the lamellar structure can be crosslinked via polymerization of the vinyl groups. After pyrolysis at high temperature, ultra-thin two-dimensional nano-silica sheets can be obtained.

New Pyrazolium Salts as a Support for Ionic Liquid Crystals and Ionic Conductors

Ionic liquid crystals (ILCs) are a class of materials that combine the properties of liquid crystals (LCs) and ionic liquids (ILs). This type of materials is directed towards properties such as conductivity in ordered systems at different temperatures. In this work, we synthesize five new families of ILCs containing symmetrical and unsymmetrical substituted pyrazolium cations, with different alkyl long-chains, and anions such as Cl⁻, BF₄⁻, ReO₄⁻, p-CH₃-₆H₄SO₃⁻ (PTS) and CF₃SO₃⁻ (OTf). We study their thermal behavior by polarized light optical microscopy (POM) and differential scanning calorimetry (DSC). All of them, except those with OTf as counteranion, show thermotropic mesomorphism. The observations by POM reveal textures of lamellar mesophases. Those agree with the arrangement observed in the X-ray crystal structure of [H₂pz^R(4),R(4)][ReO₄]. The nature of the mesophases is also confirmed by variable temperature powder X-ray diffraction. On the other hand, the study of the dielectric properties at variable temperature in mesomorphic (Cl⁻ and BF₄⁻) and non-mesomorphic (OTf) salts indicates that the supramolecular arrangement of the mesophase favors a greater ionic mobility and therefore ionic conductivity.