Effective proton conducting sites and establishing proton channels are two critical factors in developing high-performance proton exchange membranes. This study first establishes a strategy in designing effective proton conducting channels for Nafion by using solution blowing of sulfonated polyethersulfone (SPES) nanofibers containing CC3, which is an emerging porous organic cage that possesses the advantages of dissolvable organic solvents and high proton conduction from its interconnected three-dimensional pore structure. Our strategy results in SPES nanofiber networks with CC3 uniformly involved in and composite membranes with Nafion-filled interfiber voids. Benefiting from such structural features, the composite membrane exhibits high proton conductivity (0.315 S cm −1 at 80 C and 100% RH), low methanol permeability (0.69 × 10 −7 cm 2 S −1 ), excellent water absorption, thermal and dimensional stability, and single-cell performance. This study provides not only a valuable reference for the application of CC3 but also a new idea for establishment of proton transfer channels. K E Y W O R D S high proton conductivity, porous organic cage CC3, proton exchange membrane, SPES nanofibers

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Thanks to the geometric and material complexity of additive manufacturing, the design space of mechanical parts has been developed, in which lattice filling structure customization can be applied to the solid filling of mechanical parts to achieve the goal of mechanical structure lightweight. A kind of diamond lattice structure unit is designed by imitating the natural method based on Design for Additive Manufacturing of mechanical parts. The mathematical model of the relative density and mechanical properties of the unit are established, and the relationship between the two is obtained, which is verified by simulations; then the relatively uniform results are obtained. The variable density hypothesis of diamond lattice structure is proposed, the methods of simulations and compression tests are used to verify the hypothesis, and the results show that the variable density structure with the density of the filling element decreasing gradually with the stress point as the center has better compression performance and concurrently verify the correctness and applicability of the equivalent modulus of elasticity mathematical model. The results of this study can be applied to the solid sandwich filling of pressure mechanical parts, and the stress density matching relationship can be carried out to further specific design.

The aim of this work was to develop flame-retarded polyamide 6 fibers using the hexaphenoxycyclotriphosphazene (HPCP) as a flame retardant by melt spinning. The influence of HPCP on the spinning process was investigated. HPCP caused a lower melting point and a higher crystallinity of polyamide 6 chips. The melt spinning temperature of the polyamide 6/HPCP composite fibers was less than the pure polyamide 6 fibers and the achievable draw ratio was determined. Structural and morphological characterization of the melt-spun fibers demonstrated good dispersion of HPCP additive. The introduction of HPCP did not change the crystal configuration of fibers in which the γ-crystal phase was predominant. The loss of mechanical properties of polyamide 6 fibers was mitigated by HPCP. The thermal behavior and flame retardancy of the polyamide 6/HPCP composite fibers was also enhanced effectively.