Preparation And Performance Of Magnetic Hollow Composite Materials Based Wooden Cellulose Fibers

Lignocellulose, which possesses better resource advantage, derives from a kind of renewable biomass resources. Therefore, more attention has been focused on applications of micro/nano materials based Lignocellulose. However, because there is a higher internal crystallinity and stronger hydrogen bonding, it is difficult to dissolve cellulose in the traditional organic solvents. At the same time, due to the surface of NCF with a lot of hydroxyl groups which easily lead to an agglomeration phenomenon, the application range of cellulose has been greatly limited. To make the cellulose with good dispersion extent, magnetic and electrical conductivity, the magnetic hollow materials based composite permeability and conductive materials was prepared, which would lay the foundation for applications of wooden cellulose with high efficiency and value-added.In this study, the micro/nano cellulose fibers based lignocellulose was prepared via ultrasonic techniques. Then, the rod-shaped Ni-P shells were synthesized based on micro or nano cellulose fibers biotemplates via electroless plating techniques. The magnetic hollow metal materials with good hollow cavity pore size was prepared via two depositions and characterized. The related performance of composite was investigated.1. By adjusting the variable factors of ultrasonic time, ultrasonic power and the concentration of cellulose, the micro/nano cellulose fibers were prepared via high-energy ultrasonic cell disruption method. The particle size diameter of micro/nano cellulose fibers was investigated through single factors and the process was optimized through the response surface method in view of the Design Expert 8.0 software.2. To make the cellulose fibers with good dispersion extent, magnetic and electrical conductivity, the magnetic hollow materials based composite permeability and conductive materials were prepared, which would lay the foundation for applications of cellulose with high efficiency and value-added to obtain the hydrophobic materials on the surface of hydrophilic materials. Firstly, the micro/nano cellulose fibers were activated and metallized by electroless Ni-P with index of dispersion extent and coatings uniformity. Secondly, the metallization process was optimized through the response surface method in view of the Design Expert 8.0 software.3. The coating morphology for different deposition time was characterized via scanning electron microscope (SEM) and biological microscope (BMS) to study the uniformity change of coating. The growth route of metal coatings on micro/nano cellulose fibers surface was investigated. Besides, the relation between chemical reaction rate and coatings growth on the cellulose fibers surface was analyzed via the thermodynamics and dynamics of electroless Ni-P system.4. Coating uniformity is a main index to identify the performance, so are micro/nano cellulose fibers. The flatness of the composite coatings enhanced with the increase in nano particles content of the coatings in process of electroless Ni and the substrate was treated via multiple electroless Ni. The results showed that nano particles can improve the uniformity extent of coating. The particle size and surface morphology of the coatings can be controlled by optimizing the experiment conditions. A layer of uniform hollow metal coating and the hollow cavity pore were obtained on cellulose fibers surface via two depositions. Bonding mechanism of interface between cellulose fibers and metal coatings was investigated.5. Micro/nano cellulose fibers were metallized via a simple electroless nickel (Ni) approach to construct hollow coatings (HCs) to investigate the formation Mechanism. The as-prepared samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), biological microscope (BMS), thermogravimetric analyses (TGA) and vibrating sample magnetometer (VSM). SEM and particle size analysis demonstrated that the hollow structure was rod-shaped. The main ingredient of metallization cellulose fibers was Ni, P and O elements and Ni was main element. The mass fractions of Ni in inside and outside walls were 51.39%, 87.59%, respectively. The particle size of metallization cellulose fibers was uniform and distribution was narrow. The results of TGA showed that the weightlessness of metallization cellulose fibers was just 7.14 wt% (m1/m2). The mass fraction of CFs in magnetic hollow coatings decreased from 16.30 to 4.56%, indicating that NaOH/Thiourea aqueous solution can dissolve the cellulose fibers. Saturation magnetization intensity of HCs with an increase in surface-to-volume ratios which was significantly lower than Ni particles saturated magnetization (32.0 emu/g), was 9.5 emu/g. The value of coercivity, remanence, resistance and conductivity was 18 Oe,0.7 emu/g,1.69 Ω and 16.65 s/cm, respectively.6. Ni-NiO/TiO2 hollow composite was prepared via two methods which included co-deposition of nano TiO2 and Ni, and pyrolytic process of TBOT and metallization cellulose fibers. The as-prepared samples were treated at 400℃ for 5 h to prepare the Ni-NiO/TiO2 hollow composite and characterized by SEM, X-ray diffraction (XRD), nitrogen adsorption/desorption and photocatalysis. SEM showed that the pore structures can be increased on hollow materials via high-heat treatment and hollow composite has excellent electrochemical performance. As anodes in lithium ion cells, the hollow composite materials show a high initial discharge capacity of 1295.8 mA·h· g"1 and still a rather high capacity of 573.2 mA·h·g-1 after 60 cycles. The magnetic hollow coatings shown here can be applied in the fields of catalysts. Here, the catalytic capacity of Metallization cellulose fibers/nano-TiO2 for Cu (Ⅱ) was 3776 mg·g-1 as the concentration of catalyst was up to 2 g/L7. The correlation between high-heat treatment and coating properties was analyzed in detail. The as-prepared samples via high-heat treatment were characterized by SEM, TG/DTG, XRD and VSM. The results showed that the hollow cavity pore morphology was not destroyed by high-heat treatment and weightlessness was up to 4.54% after 100 ℃. The XRD pattern of the metallization cellulose fibers via high-heat treatment ranging from 300 to 500℃ corresponding to Ni3P diffraction peak appeared, indicating that the phase of NixPy appeared in the process of crystallization. The final product of crystallization was the mixture of Ni and M3P. The deposited Ni on cellulose fibers surface had crystallite size in ranging from 4.7 to 26.8 nm. The crystal form of metallization cellulose fibers via 400℃ high-heat treatment was good and it was suitable for preparation the permanent magnet. Besides, it is obvious that the saturated magnetization and coercivity of metallization cellulose fibers had great variation, indicating that the crystal form structure has changed as the coatings were treated via high-heat treatment ranging from 300 to 400℃.