Salecan, a water-soluble extracellular β-glucan, has emerged as a promising candidate for preparing hydrogel biomaterials recently. Herein, photo cross linked composite hydrogels, composed by salecan/poly ( N-tert -butylacrylamide-co-acrylamide) network andα-Mo 2 C nanoparticles were prepared by ultraviolet (UV) light, using Irgacue 2959 as photo initiator. The XRD and EDX analysis illustrated the presence of embeddedα-Mo 2 C nanoparticles throughout the hydrogel matrix. Compression tests and thermal analysis revealed that the incorporation of α-Mo 2 C nanoparticles enhanced mechanical strength and thermal stability due to the structural reinforcement of the composite hydrogels. Moreover, the change of salecan content provided a mean to tailor both the swelling property and morphology of the composite hydrogels. Encapsulation of L929 and 3T3-L1 cells and the following viability test showed the excellent cell-compatibility of these hydrogels. Taken together, these studies support the use of photo crosslinked composite hydrogels as tunable biomaterials for cell adhesion.
Chemical doping is a critical factor in the development of new superconductors or optimizing the superconducting transition temperature (Tc) of the parent superconducting materials. Herein, a new simple urea approach is developed to synthesize the N-doped α-Mo2C. Benefiting from the simple urea method, a broad superconducting dome is found in the Mo2C1-xNx (0 ≤ x ≤ 0.49) compositions. XRD results show that the structure of α-Mo2C remains unchanged and that there is a variation of lattice parameters with nitrogen doping. Resistivity, magnetic susceptibility, and heat capacity measurement results confirm that the superconducting transition temperature (Tc) was strongly increased from 2.68 K (x = 0) to 7.05 K (x = 0.49). First-principles calculations and our analysis indicate that increasing nitrogen doping leads to a rise in the density of states at the Fermi level and doping-induced phonon softening, which enhances electron-phonon coupling. This results in an increase in Tc and a sharp rise in the upper critical field. Our findings provide a promising strategy for fabricating transition metal carbonitrides and provide a material platform for further study of the superconductivity of transition metal carbides.
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