Enzymatic reduction of CO2 is of great significant, which involves an efficient multienzyme cascade system (MECS). In this work, formate dehydrogenase (FDH), glutamate dehydrogenase (GDH), and reduced pyridine nucleotide (NADH) (FDH&GDH&NADH), formaldehyde dehydrogenase (FalDH), GDH, and NADH (FalDH&GDH&NADH), and alcohol dehydrogenase (ADH), GDH, and NADH (ADH&GDH&NADH) were embedded in ZIF-8 (one kind of metal organic framework) to prepare three kinds of enzymes and coenzymes/ZIF-8 nanocomposites. Then by dead-end filtration these nanocomposites were sequentially located in a microporous membrane, which was combined with a pervaporation membrane to timely achieve the separation of product methanol. Incorporation of the pervaporation membrane was helpful to control reaction direction, and the methanol amount increased from 5.8 ± 0.5 to 6.7 ± 0.8 μmol. The reaction efficiency of an immobilized enzymes-ordered distribution in a membrane was higher than that disordered distribution in the membrane, and the methanol amount increased from 6.7 ± 0.8 to 12.6 ± 0.6 μmol. Moreover, it appeared that introduction of NADH into ZIF-8 enhanced the transformation of CO2 to methanol from 12.6 ± 0.6 to 13.4 ± 0.9 μmol. Over 50% of their original productivity was retained after 12 h of use. This method has wide applicability and can be used in other kinds of multienzyme systems.

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(SiO2/PEI) n films with structural colors on polyester fabrics were fabricated using negatively charged SiO2 nanoparticles and positively charged polyethyleneimine (PEI) using the electrostatic self-assembly approach. The bright and variable structural colors of polyester fabrics coated with a (SiO2/PEI) n film were investigated through the color photos captured by a digital camera, and also through the reflectance spectra and the images measured by a DigiEye system and a multi-angle spectrophotometer. The morphological structure of (SiO2/PEI) n films was characterized by scanning electron microscopy (SEM), and the electrostatic self-assembly process and the driving forces of fabricating the (SiO2/PEI) n films were investigated and schematically illustrated. The results showed that the structural colors varied with the various assembly cycles and viewing angles; both the optical properties indicated by the structural colors and the morphological structures illustrated by the SEM images confirmed that the (SiO2/PEI) n film on a polyester fabric was a homogeneous porous composite monolayer, with structural colors originated from single thin film interference; the self-assembly process of (SiO2/PEI) n film on a polyester fabric was driven by multi-forces, with dominant forces equilibrium of electrostatic attraction and repulsion.

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