Improvement of the Heat Resistance of Prussian Blue Nanoparticles in a Clay Film Composed of Smectite Clay and ε-Caprolactam

Effects of caprolactam content on curdlan-based food packaging film and detection by infrared spectroscopy

In this study, we report a rapid statistical approach used in determining the caprolactam (CPL) content in curdlan packaging films, which is based on the spectral data observed in the near-infrared (NIR) and Mid-infrared (MIR) regions. At the first stage of the study, the CPL content was added into the curdlan films prepared by controlling the concentration, and then the effect of the CPL concentration on the measured mechanical properties of the produced films were evaluated. At the next stage, the NIR and MIR spectra of the curdlan films with different CPL concentrations were recorded by using the FT-NIR and FT-IR spectroscopy technique, and the spectral data to be used in the regression models in our quantitative analyses were carefully selected. It was observed that the curdlan film with 5% CPL exhibited the best mechanical properties. The obtained best correlation parameters which are used in evaluation of CPL content through the observed NIR and MIR spectral data are Rp = 0.9552, RMSEP = 1.2506 (NIR); Rp = 0.9092 and RMSEP = 1.9136 (MIR), respectively. These optimal values support the expectation that our statistical approach based on NIR and MIR data can provide a rapid, accurate and nondestructive way of determining CPL content in curdlan packaging films.

A 3D graphene current collector boosts ultrahigh specific capacity in a highly uniform Prussian blue@graphene composite as a freestanding cathode for sodium ion batteries

For the first time, a uniform graphene aerogel (GA) supported Prussian blue (PB) nanocube structure was synthesized by fitting the nanocube into the GA with a specific pore size and employing it in a freestanding sodium ion battery cathodic electrode. In this electrode, the graphene framework not only offers mechanical support, but also plays the role of a binder-free current collector. The theoretical specific capacity of Prussian blue was exceeded with an ultrahigh specific capacity of 214 mA h g-1 at 0.5 C. With the help of the electronic double layer capacitance of the graphene framework, this ultrahigh value can be achieved. We studied the influence of the mass loading of the PB nanocube on the specific capacity, finding that the GA-induced freestanding electrode has the potential to load a maximum of 72 wt% of the PB nanocube. Furthermore, we separated the capacitance and the capacity of the electrode through kinetic analysis, and discovered that the GA-induced carbon collector contributed to a surface-controlled capacitance, which accounted for 55% of the total capacity.