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Hygroscopicity affects the chemical and physical stabilities of paper-based historical relics. In this research, the moisture sorption behavior of naturally aged bamboo paper dating from the Qing Dynasty to the Republic of China, and artificially aged and untreated modern bamboo paper was investigated using dynamic vapor sorption analysis (DVS). The results were fitted by sorption models to analyze the regularities of changes in the moisture absorption of aged bamboo paper. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used to characterize the chemical and physical structures of aged bamboo paper. It was found that untreated and aged bamboo paper showed similar moisture sorption isotherms at 25 °C, indicating that aging did not alter the sorption mechanism of paper. Guggenheim Anderson de Boer (GAB) and Hailwood Horrobin (H–H) models provided good fits to the experimental data and meaningful physical parameters regarding the effective sorption surface area (S GAB), monolayer water content (W 0), and multilayer water content (W s), showing that the S GAB , W 0 , and W s of naturally and artificially aged bamboo paper were decreased. Results of FTIR demonstrated that the levels of hydrophilic groups decreased, causing a reduction in the effective adsorption sites of naturally and artificially aged bamboo paper, which was the principal reason for a decrease in their hygroscopicity. The fiber structure damage of naturally and artificially aged bamboo paper was observed through microscopic morphology, which has different influences on the capillary adsorption of paper depending on the extent of degradation. [ABSTRACT FROM AUTHOR]

Abstract: PbS microcrystals including multipods, truncated octahedrons and cubes were produced by the reaction of PbCl2 and thiosemicarbazide (CH5N3S) using diethylene glycol (DEG) as a solvent at 180°C. When the reaction time was prolonged, the final products grew into single-crystalline PbS cubes with diameters in the range of 0.3–2μm. A possible formation mechanism of the PbS cubes was proposed based on their shape evolutions. By changing the reactants or/and solvents, PbS dendrites and flowers could also be produced with high yield. It is found that the reaction temperature, reactants and solvents play important roles on the shape evolutions of the PbS microcrystals. [Copyright &y& Elsevier]

• A quantitatively method is developed to analyze coupling pyrolysis of composites. • Coupling effect on FR-composites in N 2 are stronger than those in air in 250–350 °C. • Coupling reaction of MDH and acid decreases the temperature of DTG peaks in 350–450 °C. • Coupling effect on FR-composites in N 2 are weaker than those in air in 450–800 °C. • Temperatures of first peaks for F exp (T) always 30 °C higher than those of F cal (T). The coupling pyrolysis behavior and mechanism of composites with multi-components are important for the formula optimization of future flame-retardant (FR) materials. Series of thermogravimetry (TG) experiments are carried out for five FR-composites with different ratios of aluminum hydroxide (ATH)/magnesium hydroxide (MDH) additives, as well as some binary material samples in N 2 and air atmospheres, respectively. A method is developed to quantitatively evaluate the different pyrolysis of real flame-retardant samples through the comparison with the corresponding mass-weighted curves of each component. It indicates that the real DTG curves of FR-composites are narrowed with larger peaks and shift towards higher temperatures always about 30 °C than the calculated ones during their pyrolysis at 250–350 °C. The results of binary systems(EVA+MDH, MDH+MCA) indicate the enhancing of acid on the early reaction of MDH at 350–450 °C. In addition, the DTG in higher temperatures are not as large as the calculated ones in air atmosphere, especially for the FR-composites with smaller ATH/MDH ratio. Finally, the morphology evolution of samples also suggests that the bubbling, breaking and charring behaviors play an important role in their coupling pyrolysis mechanism in different temperature ranges. This is a new method for investigating the pyrolysis mechanism of FR-composites through quantitatively analyzing the DTG data and real-time morphology monitoring, which deepens the understanding of their complicated chemical and physical reactions when heated. [ABSTRACT FROM AUTHOR]

• Size-tunable SnS 2 /RGO make facile study the effect of particle size on Li/Na storage. • Ions diffusion coefficient, surface and diffusion capacitive contribution are studied. • Small-sized particle promotes charge/ion transfer and pseudocapacitor contribution. • Controllable dimension promotes fast kinetics for high rate materials. Controlling the particle sizes of electrode materials has long been recognized as an effective way to improve the cycle stability and rate property of both lithium-ion battery (LIB) and sodium-ion battery (SIB). In this paper, a simple one-step hydrothermal process for the preparation of composites with size-tunable tin disulfide on reduced graphene oxide (SnS 2 /RGO) is reported. These novel material allow to comprehensively study the effect of particle sizes on electrochemical properties for LIB and SIB anodes. The structure, morphology, phase compositions, and Li+/Na+ storage behaviors of three different SnS 2 /RGO composites obtained at heat-treatment times of 12, 24 and 48 h are characterized systematically. The electrochemical reaction kinetics is demonstrated by differential charge capacity plots and apparent ion diffusion coefficients. Surface capacitive and diffusion-controlled capacitive contributions to lithium/sodium ions storage are also compared. The results show that the small-sized nanoarchitecture can promote both the charge and ions transfer and thus improve the pseudocapacitor contribution. The reversible capacity maintains at 1211 mAh g−1 for LIB after 200 cycles and 841 mAh g−1 for SIB after 100 cycles, respectively, which is superior to most of the previous reports. This work is expected to provide a profound understanding of composite anodes with controllable dimensions and fast kinetics. The effect of SnS 2 nanoparticle size on the Li and Na storage characteristics of SnS 2 /RGO composite anodes are compared, it show that the decreased particle size promotes the pseudocapacitor contribution, as well as the reversed conversion reaction and structural stability. Image, graphical abstract [ABSTRACT FROM AUTHOR]

• A novel fiber optic temperature sensor based on multimode interference is proposed. • The sensitivity is improved by splicing NCFs with different diameters and tapered fusion. • An ultra-high temperature sensitivity of −14.448 nm/K is achieved. • The reproductivity and repeatability of the proposed sensor are remarkable. For the advancement of temperature monitoring devices, research into high sensitivity fiber optic temperature sensors is valuable. This research suggests a fiber optic temperature sensor with great sensitivity. Specifically, the NCF (no core fiber) spliced with various diameters is employed within the multimode interference region of the typical SNS (single mode fiber-no core fiber-single mode fiber) sensor. The morphology of the splice sites connecting two NCFs is also regulated by fusing. The mixture of ethanol and glycerol is used to coat the entire structure. According to the experimental results, the proposed sensor can achieve a temperature sensitivity of −14.448 nm/°C. Additionally, the sensor has good performance in repeatability and temperature cycling thanks to its simple, dependable structure. It is anticipated that the relevant results will be useful for the development and applications of precise temperature measurement. [ABSTRACT FROM AUTHOR]