Narrow Results

The investigation of the degradation of two commercially available dyes (Remazol Turquoise Blue and Everzol Turquoise Blue) by the lignin-degrading fungus Phanerochaete chrysosporium and comparison with that of a phthalocyanine whose structure is known (Heligon Blue) are presented. Atomic absorption showed a large release of copper from the biomass at day 7. Polarography served to speciate the copper present in the supernatant. Day 5 sees the complete disappearance of the main dye peak with the release of free copper into the supernatant. Day 7 sees a large increase in the free copper signal with two other electroactive species also present in the supernatant, all of which are seen to decrease at day 8. Visible spectroscopy shows that the main decolourization takes place between day 4 and day 6, with complete decolourization occurring at day 7. HPLC analysis again confirms the above results, with possible degradation products detected at 254 nm occurring at 3.621 and 4.170 min at day 7 which may well correlate with those found in polarographic analysis at –1050 and –1150 mV. Day 7 also sees a large increase in a peak at 2.744 min.

In this study, water swelling coefficients and activation energies for eucalyptus and poplar woods were calculated. The swelling properties of both species appear to directly proportional dependence on temperature and its directions. In the tangential direction, the swelling rate coefficients of eucalyptus ranged from 0.30 to 0.69 are greater than that of poplar which ranged from 0.24 to 0.55. In comparison to average activation energy (E_a), poplar approximately have 2.6 kJ/mole higher E_a than eucalyptus (36.7 vs 39.3 kJ/mole). The comparison and the measured results reveal that the swelling response of both woods with temperature can be quite well predicted using Arrhenius kinetic theory.

Biodegradable composite films based on chitosan and lignin with various composition were prepared via the solution-casting technique. FT-IR results indicate the existence of hydrogen bonding between chitosan and lignin, and SEM images show that lignin could be well dispersed in chitosan when the content of lignin is below 20 wt% due to the strong interfacial interaction. As a result of strong interaction and good dispersion, the tensile strength, storage modulus, thermal degradation temperature and glass transition temperature of chitosan have been largely improved by adding lignin. Our work provides a simple and cheap way to prepare fully biodegradable chitosan/lignin composites, which could be used as packaging films or wound dressings.

Low density polyethylene (LDPE)/lignin blends were prepared using melt blending. Two kinds of compatibilizers, ethylene-vinylacetate (EVA) which is softer than LDPE and polyethylene grafted with maleic anhydride (PE-g-MA) which is harder than LDPE were used to improve the interfacial adhesion. Scanning electron microscope (SEM) was used to investigate the dispersion of lignin in LDPE matrix. The results showed that both of the compatibilizers could improve the interaction between the low density polyethylene and lignin. However, the effects of the two compatibilizers on the mechanical properties of LDPE/lignin blends were different. The elongation at break of the blends was obviously increased by adding EVA, while significant improvement of tensile strength was observed by adding PE-g-MA. Several theoretical models have been used to further analyze the experimental data, combined with the morphological observation of tensile fractured surfaces by SEM.

In this study, a novel method, electrospinning, was used to prepare lignin-based carbon nanofibers. The major material was lignin. The chemical and thermal properties of different lignins were characterized to determine their suitability for partial incorporation of polyacrylonitrile (PAN). Then the precursor fibers were carbonized at a temperature from 600°C to 1000°C, respectively to prepare biomass-based carbon nanofibers. The influences of carbonization temperature on prepared carbon nanofibers were investigated by X-ray diffraction (XRD), Raman, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The results indicated that the diameter of prepared precursor fibers and carbon fibers were about 200nm and 100nm, respectively. The increase of temperature has little influence on the carbon fiber graphitization degree. The D band of the carbon fibers carbonized at 900°C is lowest. The thermal stability of the carbon fibers changes little with rising temperature when carbonized temperature exceeds 900°C, and carbon fibers carbonized under 900°C have most compact structure. Therefore, the above conclusions make clearly that 900°C is the optimal carbonization temperature for preparing lignin-based carbon nanofibers in this technique. Meanwhile, the study is a doubled-edged enterprise that aims to recycle the waste from pulping industry as well as to turn it into a valuable material.

Lignin-based carbon nanomaterials (LCN) were prepared from alkaline lignin (AL) by hydrolysis, spray drying and high temperature treatment. Then, the physical and chemical structures of LCN were analyzed by SEM, BET, organic element analyzer, FTIR, Raman, UV–vis and XPS. The results showed that the yield of LCN was 26.34% of the mass of AL. The particle size of LCN was 120–350 nm, and three to seven particles with diameter of 40–100 nm are accumulated. Its specific surface area was 374.74 m²/g with the average pore size of 4.79 nm. The ratio of sp² to sp³ was 1.39 and the band gap was 3.42 eV. The simplified apparent formula of LCN was C${}_{21}$H₄O with an unsaturation of 20, containing C–C, C=C, C–O, O=C–O and C–H groups. The chemical structure model of LCN was constructed by Chem 3D software. Therefore, this study successfully prepared a special material and analyzed its physical and chemical structure, which was conducive to the structural analysis of carbon nano-materials.

Different biomaterials have different chemical compositions and since the densification properties are strongly related to feedstock, it is important to increase knowledge about biomass relationship to densification properties. The purpose of this chapter is to give a brief introduction to the development of the plant kingdom, the chemical composition of biomasses, and how different components can affect the densification characteristics. A study where 11 different pure substances (cellulose, hemicelluloses, lignin, etc.), added to pine and beech, are pelletized in a single pellet press and results are presented showing that polysaccharides can play an important role when biomasses are densified as single sources or blends solutions in a densification process.

The sun is the only source of renewable energy available to us, if geothermal energy is not taken into account. In the form of radiation (UV light, visible light, infrared light, Section 1.1) it sends us annually 178,000 terawatts (1 TW = 10¹² W; unit of power 1 W = 1 J s^–1 = 859.85 calories per hour), that is to say 15,000 times the energy consumed annually by humanity. Only 0.1% of the solar energy received by planet Earth is converted into plant biomass, i.e. 100 × 10⁹ tons per year which corresponds to ca. 180 × 10⁹ tons per year of CO₂ captured from the atmosphere. This CO₂ returns to the biosphere after the death of the plants. Consumption of fossil carbon emits ca. 35 × 10⁹ tons of CO₂ yearly. Biomass is the material produced by all living organisms (plants, animals, microorganisms, fungi)…

In this paper, a new cationic type asphalt emulsifier of triethylenetetraamine/formaldehyde modified lignin amine was synthesized by the reaction of lignin, triethylenetetraamine, sodium hydroxide and formaldehyde. The synthesis process was determined through the online Fourier transform infrared spectroscopy (FTIR) technique and the intermediate was identified. The synthesized asphalt emulsifier exhibited excellent surface activity and satisfactory emulsification effect, with higher storage stability. This emulsifier belongs to the group of medium-set asphalt emulsifier and it is suitable for application in road pavement construction of chip seal and tack coat.