Qiufang Yao

A simple, one-step hydrothermal approach to durable and robust superparamagnetic, superhydrophobic and electromagnetic wave-absorbing wood.

In this work, lamellar MnFe2O4 was successfully planted on a wood surface through the association of hydrogen bonds via the one-pot hydrothermal method. Simultaneously, the fluoroalkylsilane (FAS-17) on the surface of the MnFe2O4 layer formed long-chain or network macromolecules through a poly-condensation process and provided a lower surface energy on the wood surface. The MnFe2O4/wood composite (FMW) presented superior superparamagnetism, superhydrophobicity and electromagnetic wave absorption performance. The results indicated a saturation magnetization of the FMW with excellent superparamagnetism of 28.24 emu·g−1. The minimum value of reflection loss of the FMW reached −8.29 dB at 16.39 GHz with a thickness of 3 mm. Even after mechanical impact and exposure to corrosive liquids, the FMW still maintained a superior superhydrophobicity performance.

Cellulose as an adhesion agent for the synthesis of lignin aerogel with strong mechanical performance, Sound-absorption and thermal Insulation

The lignin aerogels that are both high porosity and compressibility would have promising implications for bioengineering field to sound-adsorption and damping materials; however, creating this aerogel had a challenge to adhesive lignin. Here we reported cellulose as green adhesion agent to synthesize the aerogels with strong mechanical performance. Our approach—straightforwardly dissolved in ionic liquids and simply regenerated in the deionized water—causes assembly of micro-and nanoscale and even molecule level of cellulose and lignin. The resulting lignin aerogels exhibit Young’s modulus up to 25.1 MPa, high-efficiency sound-adsorption and excellent thermal insulativity. The successful synthesis of this aerogels developed a path for lignin to an advanced utilization.

A 3D titanate aerogel with cellulose as the adsorption-aggregator for highly efficient water purification

Making full use of the hydrophilicity, hydroxyl reactivity, high strength and stiffness, low weight and biodegradability of cellulose, a novel cellulose-based adsorption-aggregator is creatively exploited. In this work, a 3D titanate aerogel with cellulose as the adsorption-aggregator has been fabricated for highly efficient water purification. Herein, the polyhydric cellulose not only acts as a crosslinking agent, but also facilitates ion-induced aggregation, which strongly promotes the adsorption efficiency of the titanate and effectively improves its inherent shortcomings as an inorganic adsorbent. The Pb2+, Sr2+, Cu2+, Ra2+, and Cd2+ adsorption capacities surprisingly reach 2.46, 1.43, 2.51, 1.22, and 1.98 mmol g−1, respectively. Moreover, it may be applied in the fields of water purification agents, oxidants, catalysts, disinfectants and photoelectrochemical components, in view of the hydroxyl oxidation, hydroxyl induction, disinfection, and water purification abilities of cellulose. Therefore, the development of cellulose adsorption-aggregating agents is both reasonable and of great value.

One-step solvothermal deposition of ZnO nanorod arrays on a wood surface for robust superamphiphobic performance and superior ultraviolet resistance

In the present paper, uniformly large-scale wurtzite-structured ZnO nanorod arrays (ZNAs) were deposited onto a wood surface through a one-step solvothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TG), and differential thermal analysis (DTA). ZNAs with a diameter of approximately 85 nm and a length of approximately 1.5 μm were chemically bonded onto the wood surface through hydrogen bonds. The superamphiphobic performance and ultraviolet resistance were measured and evaluated by water or oil contact angles (WCA or OCA) and roll-off angles, sand abrasion tests and an artificially accelerated ageing test. The results show that the ZNA-treated wood demonstrates a robust superamphiphobic performance under mechanical impact, corrosive liquids, intermittent and transpositional temperatures, and water spray. Additionally, the as-prepared wood sample shows superior ultraviolet resistance.

3D assembly based on 2D structure of Cellulose Nanofibril/Graphene Oxide Hybrid Aerogel for Adsorptive Removal of Antibiotics in Water

Cellulose nanofibril/graphene oxide hybrid (CNF/GO) aerogel was fabricated via a one-step ultrasonication method for adsorptive removal of 21 kinds of antibiotics in water. The as-prepared CNF/GO aerogel possesses interconnected 3D network microstructure, in which GO nanosheets with 2D structure were intimately grown along CNF through hydrogen bonds. The aerogel exhibited superior adsorption capacity toward the antibiotics. The removal percentages (R%) of the antibiotics were more than 69% and the sequence of six categories antibiotics according to the adsorption efficiency was as follows: Tetracyclines > Quinolones > Sulfonamides > Chloramphenicols > β-Lactams > Macrolides. The adsorption mechanism was proposed to be electrostatic attraction, p-π interaction, π-π interaction and hydrogen bonds. In detail, the adsorption capacities of CNF/GO aerogel were 418.7 mg·g−1 for chloramphenicol, 291.8 mg·g−1 for macrolides, 128.3 mg·g−1 for quinolones, 230.7 mg·g−1 for β-Lactams, 227.3 mg·g−1 for sulfonamides, and 454.6 mg·g−1 for tetracyclines calculated by the Langmuir isotherm models. Furthermore, the regenerated aerogels still could be repeatedly used after ten cycles without obvious degradation of adsorption performance.

Bio-Inspired nacre-like nanolignocellulose-poly (vinyl alcohol)-TiO 2 composite with superior mechanical and photocatalytic properties

Nacre, the gold standard for biomimicry, provides an excellent example and guideline for assembling high-performance composites. Inspired by the layered structure and extraordinary strength and toughness of natural nacre, nacre-like nanolignocellulose/poly (vinyl alcohol)/TiO2 composites possessed the similar layered structure of natural nacre were constructed through hot-pressing process. Poly (vinyl alcohol) and TiO2 nanoparticles have been used as nanofillers to improve the mechanical performance and synchronously endow the superior photocatalytic activity of the composites. This research would be provided a promising candidate for the photooxidation of volatile organic compounds also combined with outstanding mechanical property.

MnO2 nanoflakes/cellulose nanofibre aerogel fabricated via ultrasonication for high-performance water desalination

MnO2 nanoflakes/cellulose nanofibre aerogel (MCNF) has been fabricated via the methods of redox reaction and ultrasonication. The SEM and TEM images demonstrate that the core–shell structure of ultrathin MCNF, possessing a 3D structure, was successfully obtained via ultrasonic control. Nitrogen adsorption analysis shows that the MCNF composites have a larger specific surface area compared with that of CNF, due to the inserted CNF inhibiting the aggregation of MnO2. The desalination capacity was evaluated by an adsorptive experiment, involving several ions (Ca2+, Mg2+, Na+ and sea water) in aqueous solution. MCNF exhibited excellent desalination behaviour towards ions in sea water, depending on both the strength of the efficient positive ionic charge and ionic radius. More interestingly, the regenerated MCNF after initial HCl and subsequent KOH treatment could be repeatedly used after ten adsorption/desorption cycles without obvious degradation of the performance. Moreover, with high desalination efficiency and reusability, and ease of separation, the aerogel is a candidate for desalination in practical applications.

Hydrothermal Synthesis of Nanooctahedra MnFe2O4 onto the Wood Surface with Soft Magnetism, Fire Resistance and Electromagnetic Wave Absorption

In this study, nanooctahedra MnFe2O4 were successfully deposited on a wood surface via a low hydrothermal treatment by hydrogen bonding interactions. As-prepared MnFe2O4/wood composite (MW) had superior performance of soft magnetism, fire resistance and electromagnetic wave absorption. Among them, small hysteresis loops and low coercivity (<±5 Oe) were observed in the magnetization-field curve of MW with saturation magnetization of 28.24 emu/g, indicating its excellent soft magnetism. The MW also exhibited a good fire-resistant property due to its initial burning time at 20 s; while only 6 s for the untreated wood (UW) in combustion experiments. Additionally, this composite revealed good electromagnetic wave absorption with a minimum reflection loss of −9.3 dB at 16.48 GHz. Therefore, the MW has great potential in the fields of special decoration and indoor electromagnetic wave absorbers.

New Insight on Promoted thermostability of poplar wood modified by MnFe 2 O 4 nanoparticles through the pyrolysis behaviors and kinetic study

In this study, we employed pyrolysis behavior and kinetics by Flynn–Wall–Ozawa method and Friedman method to analysis the thermostability of the MnFe2O4 nanoparticles/poplar wood composite, and analyzed the change of different proportion of MnFe2O4 in these composites for the thermostability by contrasting activation energy between the different samples. The pyrolysis processes of these composites were comprehensively investigated at different heating rates (10, 20, 30 and 40 °C/min−1) and pyrolysis temperatures of 600 °C in N2 and air atmosphere. These results indicated the thermostability of composites improved as the proportion of the MnFe2O4 nanoparticles increased. And the structure analyses of these composites from the microscopic view point of nanoparticles were applied to analysis the reason of thermostability enhancement of the poplar wood after coating MnFe2O4 nanoparticles. Additionally, due to its high initial oxidative decomposition temperature under air atmosphere, this composite and its preparation method might have high application potential, such as flameresistant material and wood security storage. This method also could provide a reference for other biomass materials. Synthesized MnFe2O4/C composite under the guidance of pyrolysis behaviors and kinetic study in N2 atmosphere exhibited good adsorption capacity (84.18 mg/g) for removing methylene blue dye in aqueous solution and easy separation characteristic.

The properties of fibreboard based on nanolignocelluloses/CaCO 3 /PMMA composite synthesized through mechano-chemical method

The purpose of this study was to develop a rapid and green method for the synthesis of lignocelluloses-based materials with superior mechanical properties. Samples were produced by hot-pressed method using different concentrations of CaCO3 and poly (methyl methacrylate) particles-filled nanolignocelluloses composites which was synthesized through mechano-chemical method. Poly (methyl methacrylate) and CaCO3 nanoparticles have been used as nanofillers. Bending strength, elasticity modulus, and dimensional stability, thermal properties of the developed lignocelluloses-based composites were determined. In view of the experimental results, it is found that the composites materials have good mechanical, dimensional stability, and thermal properties which enhanced as the filler loading increased. Thus, herein described lignocelluloses-based materials showed important characteristics to be concluded that these composites are suitable to be used for the design of flooring and construction systems.