In this study, a novel flexible and robust dual-network supramolecular elastic film with solvent resistance and brilliant structural colors was prepared by combining a Zn2+-crosslinked supramolecular elastic film with polystyrene@silica (PS@SiO2) colloidal crystals. This structurally colored supramolecular elastic material consisted of a covalent support network formed by three different monomers and a Zn2+-crosslinked polyacrylic acid (PAA) coordination network, which provided high mechanical strength and flexibility. The tensile and compression stress of this structural color reached 3.26 MPa at a strain of 187% and a pressure of 300 N. The reflectance wavelength of the structural color film remained unchanged after loading–unloading cycles and compression cycles. The structural color film could be bent and unfolded without heating or the application of an external stimulus. Moreover, the structural color film exhibited resistance to solvents in saturated organic vapors and remained color invariant.
The ability of membrane technologies to dynamically tune the transport behavior for gases and liquids is critical for their applications. Although various methods have been developed to improve membrane success, tradeoffs still exist among their properties, such as permeability, selectivity, fouling resistance, and stability, which can greatly affect the performance of membranes. Existing elastomeric membrane designs can provide antifracture properties and flexibility; however, these designs still face certain challenges, such as low tensile strength and reliability. Additionally, researchers have not yet thoroughly developed membranes that can avoid fouling issues while realizing precise dynamic control over the transport substances. In this study, we show a versatile strategy for preparing graphene oxide-reinforced elastomeric liquid gating membranes that can finely modulate and dynamically tune the sorting of a wide range of gases and liquids under constant applied pressures. Moreover, the produced membranes exhibit antifouling properties and are adaptable to different length scales, pressures, and environments. The filling of graphene oxide in the thermoplastic polyurethane matrix enhances the composites through hydrogen bonds. Experiments and theoretical calculations are carried out to demonstrate the stability of our system. Our membrane exhibits good stretchability, recovery, and durability due to the elastic nature of the solid matrix and dynamic nature of the gating liquid. Dynamic control over the transport of gases and liquids is achieved through our optimized interfacial design and controllable pore deformation, which is induced by mechanical stimuli. Our strategy will create new opportunities for many applications, such as gas-involved chemical reactions, multiphase separation, microfluidics, multiphase microreactors, and particulate material synthesis.
Fan Zhang,Qun Zhang,Jian Yang,Yawen Zhou,Zhaohui Zhou,Ce Wang
Interface dilational rheology is useful for understanding and exploring the role of interface phenomena. However, relatively few studies have been conducted on the interface dilational rheological properties of N-acyl aromatic amino acid surfactants. Herein, surface tension and the dynamic interface tension and dilational rheological properties of three surfactants, namely, sodium N-lauroyl phenylalaninate (SLP), sodium N-lauroyl tyrosinate (SLTy), and sodium N-lauroyl citrate (SLTr) were investigated. The results show that the order of critical micelle concentration, which includes the surface tension at the critical micelle concentration, minimum area per surfactant molecule, and interfacial tension, was SLTr < SLTy < SLP. At a low surfactant concentration, the three surfactants exhibited a low-viscosity interfacial elastic film at the n-decane/water interface. The dilational modulus increased and the phase angle decreased with increase in frequency. However, the order of the dilational modulus was SLP < SLTy < SLTr, while the order of the phase angle change was SLTr < SLTy < SLP at the same frequency. With increase in surfactant concentration, the dilational modulus of SLP and SLTy increased and then decreased after a maximum value; however, the dilational modulus plot of SLTr demonstrated two maxima.