The non-flow property for rigid-rod polymers remains a serious problem that limits their application on a massive scale. Based on a water-in-oil microemulsion method and one pot in situ “grafting to” strategy, a series of novel poly(p-phenylene terephthalamide)-based materials containing controllable graft density of long-chain tertiary amine are prepared. Consequently, the materials’ rheology behaviors are controllable at the level of an order of magnitude and are well-matched with the tunable condensed state structures. Several significant micro-structures of such liquid-like poly(p-phenylene terephthalamide)-based materials are obtained. Additionally, the excellent solubility conforms to the liquid crystal states, solving the key problem of only dissolving concentrated sulfur acid. Additionally, we further investigated the liquid crystal states in different solvents, mass ratios and temperature. This state-of-the-art material with its established property-structure relationship, especially regarding how the structure determines the rheology behavior and solubility, can be treated as a prototype for guiding future research on ionic liquids and in the field related to functional polymer science and technology . Furthermore, the dielectric properties of f -PPTA/PVDF composite membranes have been investigated and show great potential for use in capacitor applications.
The blood–brain barrier is one of the serious challenges in the treatment of Parkinson's disease (PD), which severely hinders the drug's brain bioavailability. In this study, a lyotropic liquid crystalline (LLC) based in situ gel nasal spray loaded with the first-line drug Levodopa (LDA) for PD is developed to resolve this issue based on a nose-to-brain drug delivery approach. Specifically, the two key stages of LLC-based in situ gel nasal spray, droplet deposition, and drug retention are tailored. By adjusting LLC's precursor solution's viscosity, the droplet deposition on the superior nasal tract can be increased by 18 times. Through nasal mucus-triggered sol–gel transition, the LDA nasal cavity retention is prolonged by three times. The epigallocatechin gallate is incorporated into the LLC-based in situ gel nasal spray to inhibit the autoxidation of LDA and alleviate the oxidative stress response in PD. The results show that the LLC-based in situ gel nasal spray has a 26-fold higher brain bioavailability of LDA compared to oral administration. The PD rats show a significant improvement in behavioral and cognitive disorders after administration. The LLC-based in situ gel nasal spray is proved to work by reducing oxidative damage. This study is anticipated to offer a promising strategy for the clinical application of LDA.
The direct synthesis of a chiral nematic liquid crystalline phase of AgNR@SiO 2 @cysteine@CsPbBr 3 hybrid nanorods (HNRs) is reported. The circular dichroism spectra can be divided into three components: (1) the interband absorption–enhanced optical activity of structural arrangement of cysteine (cys) molecules, 200–320 nm, (2) the chiral nematic liquid crystalline arrangement of the Ag nanorods (AgNRs), 350–450 nm, and (3) the exciton adsorption edge of the perovskite, 500–550 nm. The polarizing optical microscope images indicate that the chiroptical response of perovskite arises from chiral nematic crystalline arrangement rather than cys-induced electronic coupling between a chiral ligand and otherwise achiral perovskite quantum dots (QDs). The luminescent intensity of CsPbBr 3 QDs in AgNR@SiO 2 @cys@CsPbBr 3 HNRs is boosted 87-fold due to the local surface plasmon resonance field enhancement effect. Furthermore, the high-performance green light emitting diode is constructed employing AgNR@SiO 2 @cys@CsPbBr 3 complexes, which exhibit excellent luminescent properties. This work contributes insights into structure–property relationships and this strategy promisingly provides guidance for the other inorganic chiral semiconductor suprastructures.
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