RESUMO
To achieve high solar energy utilization efficiency, photothermal materials with broadband absorption of sunlight and high conversion efficiency are becoming a fast-growing research focus. Inspired by the forest structure with efficient sunlight utilization, we designed and fabricated a graphene film consisting of densely arranged porous graphene though laser scribing on polybenzoxazine resin (poly(Ph-ddm)). This hierarchical structure significantly reduced the light reflection of graphene as a 2D material. With a combination of advanced photothermal conversion properties of graphene, the 3D structured graphene film, named forest-like laser-induced graphene (forest-like LIG), was endowed with a very high light absorption of 99.0% over the whole wavelength range of sunlight as well as advanced light-to-heat conversion performance (reaching up to 87.7 °C within 30 s under the illumination of simulated sunlight and showing an equilibrium temperature of 90.7 ± 0.4 °C). As a further benefit of its superhydrophobicity, a photothermal actuator with quick actuated response and high motion velocity, as well as a solar-driven interfacial desalination membrane with durable salt-rejecting properties and high solar evaporation efficiencies, was demonstrated.
RESUMO
A biobased benzoxazine resin (Dz-f) demonstrating excellent thermal properties was synthesized from daidzein and furfurylamine by using a microwave heating method. The chemical structure of synthesized benzoxazine monomer was identified by FTIR and NMR (1 H and 13 Câ NMR) before it was cured and its thermal properties evaluated by differential scanning calorimetry (DSC), TGA, and dynamic mechanical analysis (DMA). The cured resin p(Dz-f) exhibited a glass transition temperature (Tg ) of 391 °C, a very high char yield of 68.7 %, and outstanding thermal stability; the Tg value obtained was the highest thermal stability value ever reported for polybenzoxazine with a high biobased content. Moreover, Dz-f demonstrated a satisfying processability, which was rare for the high-performance thermosetting resins. This work provided us with a new strategy for the preparation of high biocontent resins with excellent thermal properties. In addition, the combination of biobased feedstocks with a microwave-assisted heating method as well as the potential application of this approach in high-end fields might perpetuate remarkable progress towards the sustainable development of the polymeric industry.
RESUMO
The molecular and metal profile fingerprints were obtained from a complex substance, Atractylis chinensis DC-a traditional Chinese medicine (TCM), with the use of the high performance liquid chromatography (HPLC) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) techniques. This substance was used in this work as an example of a complex biological material, which has found application as a TCM. Such TCM samples are traditionally processed by the Bran, Cut, Fried and Swill methods, and were collected from five provinces in China. The data matrices obtained from the two types of analysis produced two principal component biplots, which showed that the HPLC fingerprint data were discriminated on the basis of the methods for processing the raw TCM, while the metal analysis grouped according to the geographical origin. When the two data matrices were combined into a one two-way matrix, the resulting biplot showed a clear separation on the basis of the HPLC fingerprints. Importantly, within each different grouping the objects separated according to their geographical origin, and they ranked approximately in the same order in each group. This result suggested that by using such an approach, it is possible to derive improved characterisation of the complex TCM materials on the basis of the two kinds of analytical data. In addition, two supervised pattern recognition methods, K-nearest neighbors (KNNs) method, and linear discriminant analysis (LDA), were successfully applied to the individual data matrices-thus, supporting the PCA approach.
