Solar energy, positioned as an eco-conscious substitute for conventional fossil fuels, holds great promise for meeting heating needs. For solar energy absorption and subsequent light-to-heat conversion, light-absorbing materials require broad-spectrum light absorption capabilities. Herein, we present the fabrication of broadband light-absorbing polypyrrole-carboxylated carbon nanotube membranes via a facile electrochemical oxidation route. By manipulating electrochemical deposition time, the structure of the membranes was tailored, resulting in enhanced absorption within the near-infrared spectrum to achieve over 98.95% light absorption across the entire solar spectrum. The membranes demonstrated exemplary thermal efficacy and insensitivity to incident angles in photothermal conversion, the membranes facilitated a notable 12 °C temperature elevation within a simulated greenhouse compared to ambient conditions. Thus, these membranes exhibit considerable potential for widespread application in photothermal conversion and greenhouse technology.
The effects of current density (Jk) and bath temperature on the structure of deposition layer of nickel and electrochemical noise energy (ED) are studied, and the relationship between the structure of the deposit and ED is also discussed in detail using electrochemical noise technique in coupled with the scanning electron microscopy and the glancing angle X-ray diffraction techniques. The results show that ED theoretically mainly reflects the severity or rate of the local cathodic reaction rather than the integral cathodic reaction, and is markedly influenced by the electroplating current density (Jk)-depended nucleation/growth kinetics of the nickel deposit film. The proceeding of the nucleation (or the formation of new phase)/growth process of crystal nucleus on a foreign substrate possesses much more effect on ED value than the subsequent homogenous growth of the already formed film particles, and the factors which can accelerate the drastic change of the electrode surface state should result in large ED value.
An electrochemical noise technique has been applied to describe the corrosion process of copper. The results show that the sampling frequency clearly changes both the energy distribution plot and the power spectral density spectra, which should be taken into consideration strictly and logically before an electrochemical noise test. The corrosion energy, (Ec), deduced using the fast wavelet transform method showed a similar variation trend with corrosion rate. Hence, the proposed parameter Ec represents the corrosion rate or severity.
To obtain amphiphilic polymers, fluorinated groups were successfully embedded in polyacrylates. The amphiphilic polymers were synthesized by free radical-initiated copolymerization using hydrophilic acrylate monomers and hydrophobic 2-perfluorooctylethyl methacrylate (FMA). 1H NMR spectroscopy and Fourier transform infrared results indicated that the fluorinated monomer FMA was successfully embedded in the polymers. The surfaces of the amphiphilic polymers were subsequently characterized by contact angle measurement, atomic force microscopy, and X-ray photoelectron spectroscopy, showing that a well-designed amphiphilic structure with fluorinated groups in the polymers was fabricated with the increase in the number of FMA units (n). Protein adsorption experiments indicated that, in addition to the surface chemical composition and roughness of the polymer, the fluorinated degree of the bulk/internal polymer layer (k) also plays a significant role in its bioadhesion behavior via adjusting the charge state of the polymer surface. With the decrease in k, the critical factor determining the protein adsorption gradually turns from the polymer's surface to its internal area, and the minimum adsorption for both bovine serum albumin and human plasma fibrinogen on the synthesized polymer surface occurs when k is approximately 12.