WOOD RESEARCH Volume 63, Number 5, 2018
Zhenzhong Tang, LILI YU, Yi Zhang, Lizhi Zhu, and Xiaojun Ma

Effects of nano-SiO2/polyethylene glycol on the dimensional stability modified ACQ treated southern pine

Southern yellow pine (Pinus sp.) wood cubes were vacuum-pressure treated with nano-SiO2 solution and different concentrations of ACQ/polyethylene glycol (0.5%, 2.5% and 5.0%) modified solutions. The effects of polyethylene glycol concentrations and nano-SiO2 addition on the water absorption, air drying shrinkage and moisture swelling stability of treated wood were investigated. The results showed that during the whole process of water absorption and air drying shrinkage, the better stability of nano-SiO2 modified ACQ treated wood could only be obtained with the ratio of 2.5% polyethylene glycol addition. However, nano-SiO2 and polyethylene glycol modification could take little effect on the moisture and water swelling resistance of treated wood with different treatments.

WOOD RESEARCH Volume 63, Number 1, 2018
Xiaojun Ma and Xiaojun Zhang

Nano-Fe3O4/ NMMO-cellulose composite membrane prepared by the in-situ co-precipitation method

Using NMMO-cellulose membrane as a matrix, Fe3O4/ cellulose composite membrane were prepared by the in-situ co-precipitation method. The effects of Fe2+ and Fe3+ salts concentration on the structure and properties of composite membranes were studied by scanning electron microscopy(SEM), X-ray diffraction(XRD), Fourier transform infrared spectrometer(FTIR) and vibrating sample magnetometer(VSM). Results showed that the spherical magnetic Fe3O4 nanoparticleswere dispersed uniformly and immobilized in the cellulose membranes, and there were good interactions between cellulose and Fe3O4 in the membranes. With increased iron ion content, the thermal stability of Fe3O4-CMgradually increases, and the complex membrane has a second significant weightlessness peak within 620–700 °C. In addition, it is also found that Fe3O4/cellulose composite membranes showed good superparamagnetic property.

WOOD RESEARCH Volume 64, Number 6, 2019
Jing Zahng, Jingjing Gao, LILI YU, Lizhi Zhu, and Xiaojun Ma

Dimensional stability of nano-SiO2/emulsified wax modified CuAz-treated wood after one year outdoor exposure test

Samples were vacuum-pressure treated with nano-SiO2 water solutions with BET specific surface area of 60,150, 200, 380 respectively, and then impregnated with copper azole (CuAz) preservatives or emulsified wax modified CuAz preservatives. The effects of emulsified wax and nano-SiO2 on the dimensional stability were investigated according to standard GB/T 1934 (2009) after one year outdoor exposure test. The results showed that the addition of nano-SiO2 or/and emulsified wax could reduce the water absorption rate of treated wood, and the best water repellent was observed in the samples treated with BET specific surface area of 60 m2.g-1. The addition of wax into nano-SiO2 modified wood was essential to improve the radial and tangential swelling and shrinkage stability of nano-SiO2 treated wood. The bigger BET specific surface area of nano-SiO2 would be adversely affected the dimensional stability of the treated wood.

WOOD RESEARCH Volume 65, Number 5, 2020
Liyan Ma, Lina Wang, Xiaojun Ma, and JIANING LI

In situ hydrothermal synthesis of MnO2 nanowires/wood derived activated carbon hollow fibers composite and its application in supercapacitor

Composite electrode material composed of MnO2 nanowires and wood-derived activated carbon hollow fibres (Mn@ACHFs) was successfully fabricated by in situ hydrothermal method. In this work, MnO2 nanowires were developed by adjusting the mass ratio of potassium permanganate and wood activated carbon hollow fibres (ACHF). The ACHF with hierarchical porous structure served not only as the support for the growth of MnO2 particles, but also as the electric double layer capacitance for the composite electrode. The Mn@ACHFs exhibited an outstanding specific capacitance of 420 F.g-1 at 1 A.g-1 and cycle stability with 99.7% capacitance retention after 5000 cycles at 5 A.g-1. Electrochemical characteristics of the prepared composites are attributed to the synergetic effect of the double layer capacitance of the hierarchical porous ACHF and the layered structure of MnO2, which can efficiently enhance the conductivity and stability of the electrodes.

WOOD RESEARCH Volume 66, Number 1, 2021
Dongna Li, JIANING LI, and Xiaojun Ma

Study on the structure and properties of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/ rubber wood fiber composites modified with titanate coupling agent

In this study, the biodegradable composites were prepared from rubber wood fibers (Hevea brasiliensis) and biopolymer poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) via hot pressing process, using the titanate as the coupling agent. The morphological, chemical structure, mechanical properties and water absorption (WA) of the composites were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), mechanical properties and WA analysis. Results showed that a new absorption peak of Ti-O-C was formed due to the addition of titanate, indicating that it was successfully grafted on the surface of wood fibers. In addition, the mechanical properties of the composites first increased and then decreased with the increasing of the titanate content. The obvious improvement of WA of composites was attributed to the inclusion of P34HB by titanate modified wood fiber. Moreover, it was also found that the optimal condition of the titanate coupling agent content was 1 wt%.