Bacterial cellulose (BC) is a promising biopolymer, but its three-dimensional structure needs to be controllable to be used in multiple fields. BC has some advantages over other types of cellulose, not only in terms of purity and properties but also in terms of modification (in situ modification) during the synthesis process. Here, starches from different sources or with amylose/amylopectin content were added to the growth medium to regulate the structural properties of BC in-situ. The obtained BC membranes were further modified by superhydrophobic treatment for oil-water separation. Starches alter the viscosity of the medium, thus affecting bacterial motility and cellulose synthesis, and adhere to the microfibers, limiting their further polymerization and ultimately altering the membrane porosity, pore size, and mechanical properties perpendicular to the BC fibril layer direction. The average pore diameter of the BC/PS membrane increased by 1.94 times compared to the initial BC membrane. The chemically modified BC/PS membrane exhibited super-hydrophobicity (water contact angle 167°), high oil-water separation flux (dichloromethane, 23,205 Lm −2 h −1 MPa −1 ), high separation efficiency (>97%). The study provides a foundation for developing methods to regulate the network structure of BC and broaden its application.
Conducting films are becoming increasingly crucial for the electronics industry with applications in various technologies including high-power microelectronic packaging, photovoltaics, and flexible displays. The films with high conductivity were normally fabricated by sintering of printed inks with micrometer size particles. However, the resolution of printed pattern and high sintering temperature limit its application due to the particle size. Herein, we report a stable bimetallic alloy nanoparticle (Au–Ag) sintering inks with low sintering temperature (450 °C). The fabricated films have low resistivity (4.13 × 10 –8 Ω·m), which is similar with that of bulk Au films (2.4 × 10 –8 Ω·m) and show great adhesion on glass substrates. Film porosity is extremely low, with a maximum transmittance of only 0.1% in the wavelength range of 340 nm-870 nm. The Au–Ag nanoparticles sintering behavior was also characterized systematically by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). It was observed that the sintering process could be divided into three stages. This work indicates that this preparation approach of conductive film shows potential in the fabrication of highly integrated electronic devices by ink printing method.
危险品化学品经营许可证（带存储）