A comparative study on the comprehensive properties of natural microfibers isolated from the large-clustered bamboos in the southwest of China using steam explosion

To develop sustainable functional fibers and expand their novel applications, the large-clustered dendrocalamus sinicus (DS) and the dendrocalamus giganteus (DG) planted in the southwest of China were effectively isolated by steam explosion (SE). The fine and uniform bamboo microfibers of DS and DG corresponding to the smallest average widths of 18.24 μm and 17.16 μm were obtained, respectively. The relative content of cellulose in two bamboo species had a marked increase after SE but a decrease for hemicellulose and lignin without any introduction of toxic chemical reagents. The SE treatment improved the thermal stability, the crystallinity, and the surface hydrophilicity of bamboo samples with their morphologies varying from rod-shaped strips to fibrous filaments. The degrees of crystallinity for DS and DG increased from 57.63% and 57.53% to 73.67% and 74.10%, respectively. The thermal stability, mechanical properties, and hydrophobicity of bamboo microfibers derived from DS were superior to those of DG, which showed a higher maximum decomposition temperature (5.24°C), tensile strength (181 MPa), elongation at break (1.1%), and water contact angle (7.8°)

A Water-Stable Proton-Conductive Barium(II)-Organic Framework for Ammonia Sensing at High Humidity

In view of environmental protection and the need for early prediction of major diseases, it is necessary to accurately monitor the change of trace ammonia concentration in air or in exhaled breath. However, the adoption of proton-conductive metal–organic frameworks (MOFs) as smart sensors in this field is limited by a lack of ultrasensitive gas-detecting performance at high relative humidity (RH). Here, the pellet fabrication of a water-stable proton-conductive MOF, Ba­(<i>o</i>-CbPhH₂IDC)­(H₂O)₄]_<i>n</i> (<b>1</b>) (<i>o</i>-CbPhH₄IDC = 2-(2-carboxylphenyl)-1<i>H</i>-imidazole-4,5-dicarboxylic acid) is reported. The MOF <b>1</b> displays enhanced sensitivity and selectivity to NH₃ gas at high RHs (>85%) and 30 °C, and the sensing mechanism is suggested. The electrochemical impedance gas sensor fabricated by MOF <b>1</b> is a promising sensor for ammonia at mild temperature and high RHs