Synthetic membranes universally exhibit a pernicious trade-off effect, on which there exists an upper bound between permeability and selectivity. Tremendous efforts are made to design crumpled membranes to further break through the bottleneck. In this work, we proposed that a nano-pleated membrane surface with ridged nanostructures enables rapid transport of water molecules. Here, a root-like, ultrathin thin film composite (TFC) membrane was carefully designed via incorporation of a sacrificial ZIF-L layer into a polyamide layer, followed by its removal in a weak acid solution. The best performing membranes displayed ultrahigh water permeances of 48.9 L m−2 h−1 bar−1 with a comparable rejection of sodium sulfate, surpassing the upper limit of conventional desalting membranes. The utilization of sacrificial ZIF-L templates in the regulation of the nanofilm morphology is suggested to be promising for fabrication of highly permeable NF membranes.
The complexity of crystal structures plays an intriguing role in manipulating properties in thermoelectrics, spintronics, and batteries. In comparison to the widely studied ternary half-Heusler thermoelectric compounds, quaternary double half-Heusler compounds are promising due to their intrinsically low lattice thermal conductivities (κL). However, they have been much less investigated due to the limited material availability. In this study, we report a new double half-Heusler compound based on ZrNi(In,Sb). Upon tuning the ratio of In/Sb from 0.5/0.5 to 0.4/0.6 and reducing the nominal concentrations of Zr and Ni by 10%, we greatly reduce the intensities of the impurity-phase peaks in the diffraction patterns. An even better phase purity, in combination with an optimized power factor, is realized by substituting Co at the Ni sites. Further alloying Hf at the Zr sites enhances the point defect scattering of phonons, which yielded a minimum κL of ∼1.8 W m−1 K−1 and a maximum zT of ∼0.5 for Zr0.7Hf0.2Ni0.65Co0.25In0.4Sb0.6 at 973 K. Our work thus confirms the intrinsically low κL of ZrNi(In,Sb) double half-Heusler compounds and indicates their promising applications upon further improving their electrical transport properties.
4 October 2021 in Journal of Biomaterials Applications
Natural cartilage tissue has excellent mechanical properties and has certain cellular components. At this stage, it is a great challenge to produce cartilage scaffolds with excellent mechanical properties, biocompatibility, and biodegradability. Hydrogels are commonly used in tissue engineering because of their excellent biocompatibility; however, the mechanical properties of commonly used hydrogels are difficult to meet the requirements of making cartilage scaffolds. The mechanical properties of high concentration polyethylene glycol diacrylate (PEGDA) hydrogel are similar to those of natural cartilage, but its biocompatibility is poor. Low concentration hydrogel has better biocompatibility, but its mechanical properties are poor. In this study, two different hydrogels were combined to produce cartilage scaffolds with good mechanical properties and strong biocompatibility. First, the PEGDA grid scaffold was printed with light curing 3D printing technology, and then the low concentration GelMA/Alginate hydrogel with chondral cells was filled into the PEGDA grid scaffold. After a series of cell experiments, the filling hydrogel with the best biocompatibility was screened out, and finally the filled hydrogel with cells and excellent biocompatibility was obtained. Cartilage tissue engineering scaffolds with certain mechanical properties were found to have a tendency of cartilage formation in in vitro culture. Compared with the scaffold obtained by using a single hydrogel, this molding method can produce a tissue engineering scaffold with excellent mechanical properties on the premise of ensuring biocompatibility, which has a certain potential application value in the field of cartilage tissue engineering.
11 November 2022 in International Journal of Refrigeration
Microfluidic chips have shown their potential for applications in fields such as chemistry and biology, and 3D printing is increasingly utilized as the fabrication method for microfluidic chips. To address key issues such as the long printing time for conventional 3D printing of a single chip and the demand for rapid response in individualized microfluidic chip customization, we have optimized the use of DLP (digital light processing) technology, which offers faster printing speeds due to its surface exposure method. In this study, we specifically focused on developing a fast-manufacturing process for directly printing microfluidic chips, addressing the high cost of traditional microfabrication processes and the lengthy production times associated with other 3D printing methods for microfluidic chips. Based on the designed three-dimensional chip model, we utilized a DLP-based printer to directly print two-dimensional and three-dimensional microfluidic chips with photosensitive resin. To overcome the challenge of clogging in printing microchannels, we proposed a printing method that combined an open-channel design with transparent adhesive tape sealing. This method enables the rapid printing of microfluidic chips with complex and intricate microstructures. This research provides a crucial foundation for the development of microfluidic chips in biomedical research.