Inspired by efficient cellulose-dissolving system: Facile one-pot synthesis of biomass-based hydrothermal magnetic carbonaceous materials.

The core-shell structure of carbon encapsulated magnetic nanoparticles (CEMNs) displays unique properties. Enhancing the magnetization of iron core, in parallel, improving the encapsulation of carbon shell are the two major challenges in the synthesis of CEMNs. Inspired by efficient cellulose-dissolving system, carbon encapsulated magnetic nano-Fe3O4 particles (Fe3O4@C) with ∼10.0nm Fe3O4 cores and 1.9-3.3nm carbon shell, were successfully one-pot synthesized via a novel hydrothermal carbonization (HTC) process. The dissolving process in ionic liquids ([Emim]Ac and [Amim]Cl) completely cleaved the intra- and intermolecular H-bonds in cellulose, and favored the incorporation of Fe3O4 nanoparticles into the cellulose H-bonds systems during the regeneration process. Some stable linkages were formed in Fe3O4@C, taking Fe3O4 nanoparticles as a structure guiding agent. The morphology and properties of Fe3O4@C depended strongly on the type of carbon precursors and pyrolysis temperature. Well encapsulated nanostructure was obtained at HTC temperature 280°C, when [Emim]Ac-treated holocellulose was used as the carbon source. Meanwhile, the thickness of the amorphous shell and magnetization increased with HTC temperature. More importantly, a novel elements for understanding the growth mechanism for the Fe3O4@C composite under HTC conditions was proposed.

[Research on Chemical Constituents of Bamboo Fiber Cell Wall Based on Nano-IR Technology].

Nano-IR technology was firstly employed on bamboo fiber research with purpose to further understand the fine structure of bamboo fiber cell wall. Chemical constituent distribution of bamboo fiber was studied, and the feasibility of the novel technology was discussed by comparing with other traditional methods. The results showed that Nano-IR technology, which has made a breakthrough on diffraction limit of traditional infrared spectroscopy, can acquire nano-scale infrared spectrum of bamboo cell wall in situ condition. The characteristic peak positions of Nano-IR spectrum is basically the same with that of microscopic FTIR spectrum, indicating that Nano-IR spectrum can reveal the chemical information of bamboo cell wall. The results of the present work suggested that nano-IR technology could be an effective research tool in research of nano chemical composition distribution of bamboo cell wall.

[Study on the Crystal Structure of Cellulose in Bamboo with Synchrotron Radiation Wide Angle X-Ray Scattering].

The crystal structure of cellulose will directly affect the properties of bamboo fiber -reinforced composite, but the unit cell of native cellulose in bamboo has never been investigated. The most accepted model for the structure of native cellulose is Meyer-Misch model which provides a reference to understand the unit cell of native cellulose in bamboo. The native cellulose consists of two different crystal structures (Ⅰ(α) and Ⅰ(ß)) which exist in different plants with different proportions. Because of this situation, the crystal structure of bamboo cellulose should have a unique model. The moso bamboo (Phyllostachys edulis (Carr. ) H. de Lehaie)was selected. The crystal structure of cellulose of bamboo was investigated with two dimensional synchrotron radiation wide angle X-ray scattering (SR-WAXS). The values of the interplanar spacings of each peak were obtained from SR-WAXS patterns, and then crystal structure parameters were calculated according to monoclinic crystal system. The results show that the fibre axis of a bamboo cellulose unit cell with a monoclinic unit cell of a=8.35 Å, b (fiber axis)=10.38 Å, c=8.02 Å, ß=84.99°. This model has a two antiparallel arrangement for the chains in unit cell, with four glucose residues. Thus, the model may be used to provide a theoretical basis for high value-added bamboo fiber -reinforced composite.

[Modified Mechanism of Cell Walls from Chinese Fir Treated with Low-Molecular-Weight Phenol Formaldehyde Resin].

Study on the modified mechanism of wood cell walls, it is very important for improving treatment reagents, optimizing treatment technology, and enhancing wood density, mechanical properties, dimensional stability, and so on. Samples of plantation Chinese fir were treated gradually with synthesized water-soluble low-molecular-weight phenol formaldehyde (PF) resins under vacuum and pressure. The correlated physical and chemical properties of the treated and untreated reference samples were determined by X-ray diffractometer (XRD), Fourier transform infrared spectrometer (FTIR), and nuclear magnetic resonance spectrometer(NMR) (Using method of Cross Polarization/Magic Angle Spinning for continuous testing) with high precision and resolution. The results showed that, after treated with water-soluble low-molecular-weight PF resin, the average values of crystallinity from the treated samples were decreased obviously, and the average reduction rate was 12.67%, 11.91% and 6.26%, respectively. Comparing water-soluble, low-molecular-weight PF resin modified Chinese fir with untreated reference samples, no new chemical shifts and characteristic peaks of functional groups from esters, ethers, etc. were present by using FTIR and ¹³C NMR spectrum. It was considered that there was no distinct chemical reaction between the water-soluble low-molecular-weight PF resin and Chinese Fir cell walls. But water-soluble low-molecular-weight PF resin could enter into the structure relatively loose, large size spaces, relatively area large amorphous regions in cell walls of Chinese fir tracheids, and form physical filling, which resulting in the decreasing of relative crystallinity. This study has important reference value for the development of new wood modification reagents and the optimization of wood modification process. The findings also provide important theoretical foundation for further proving the modification mechanisms of wood cell walls and enriching the modified theories of wood cell walls.

[Distribution of lignin in Chinese fir branches determined by ultraviolet microspectrometer].

Distribution of lignin in the cell walls of Chinese fir branches emerged in the spring season were first studied by using ultraviolet microscope based on their cell microstructure observation and lignin qualitative measurement by the lightmicroscope and confocal laser scanning microscope. The results showed that the contents of lignin are inhomogeneously distributed in different micro-areas of the cell walls. The order of lignin concentrations is the cell corner>the middle lamellar>the secondary with the absorbance values of ultraviolet wave of 0.489, 0.307 and 0.278, respectively. The result of quantitative analysis consists with that of qualitative analysis. A new measurement method was proposed to study the distribution of lignin content in wood cell walls in CFhina.

[Study on chemical compositions and crystallinity changes of bamboo treated with gamma rays].

The structures and qualities of main chemical compositions in cell wall of bamboo treated with gamma rays were tested by nuclear magnetic resonance spectrometer (NMR) and X-ray Diffraction (XRD). The result indicated that the bamboo crystallinity increased at the beginning of irradiation process, while the crystallinity reduced when the irradiation dose was raised to about 100 kGy. During the whole irradiation process, hemicellulose degraded, and with the irradiation doses increased the non-phenolic lignin changed to the phenolic.

[Study on bamboo treated with gamma rays by X-ray diffraction].

The microfibril angle and crystallinity of bamboo treated with gamma rays were tested by X-ray diffraction (XRD). The result indicated that crystallinity in bamboo increased when irradiation dose was less than 100 kGy, while the irradiation dose was raised to about 100 kGy, crystallinity in bamboo reduced. But during the whole irradiation process, the influence on microfibril angle was not obvious, so it was not the dominant factors on variation in physical-mechanical properties of bamboo during the process of irradiation.

[Analysis of effects of irradiation on the crystal size of daemonorops margaritae with X-ray diffractometry].

In order to find the relationships between the crystal size and the physical & mechanical properties, and to improve the levels of high value-added processing and utilizing for Chinese rattan resources, the daemonorops margaritae, Chinese unique rattan, was chosen as the research material, then the crystal size was measured and analyzed through the X-ray diffraction method before and after gamma-ray irradiation. The results show that the crystal width is in the range between 1.901 and 3.019 nm, and the average width is 2.403 nm. The crystal length is in the range between 4.118 and 28.824 nm with an average length of 10.907 nm. After irradiation, the width of daemonorops margaritae is in the range between 2.139 and 3.540 nm, and the average width is 2.569 nm, and the crystal length dramatically changes in the range between 5.765 and 38.432 nm with a mean of 15.530 nm. Both of the scope and the mean value of the crystal width and length increase after irradiation.

[Analysis of the microfibrilla angles & crystallinity index of Daemonorops Margaritae with X-ray diffractometry and the effects of gamma-ray irradiation].

In order to find out the properties and improve the levels of high value-added processing and utilization of Chinese rattan resources, the Daemonorops Margaritae, a Chinese unique rattan, was chosen as the research material, then the microfibril angles (MFA) & crystallinity index (CrI) were measured through the X-ray diffraction method, and the effects of gamma-ray irradiation upon the MFA & CrI were analyzed. The results show that the MFA of the cane varied from 33.4 degrees to 38.7 degrees with the average value of 36.1 degrees, and the MFA of the coretex were not larger than that of the core. The MFA were 36.2 and 35.8 degrees, 35.9 and 35.4 degrees, and 36.2 and 35.4 degrees before and after irradiation with a radiation dose rate of 2.5 x 10(3) Gy x h(-1) and radiation dose of 3, 9 and 15 kGy, and decreased 1.10%, 1.39% and 2.21% respectively compared with the former. The CrI was in the range of 24.8%-32.0%, and the average CrI was 28.6%. The CrI of coretex was larger than that of the core. Under the same radiation conditions, the CrI was 28.1% and 26.0%, 28.1% and 26.9%, and 28.5% and 27.1% before and after irradiation, and the latter decreased 7.58%, 4.34% and 4.70% respectively compared to the former. With the radiation dose of 3 kGy, the differences in CrI between with and without irradiation were most notable in the 0.001 level.

[Determination of metal elements in paper sludges by ICP-AES].

Metal elements, especially the heavy metal element, need to be considered for resource utilization of paper sludge. Seventeen kinds of metal elements were determined by ICP-AES method, which were form two kinds of paper sludge from Anhui Shanying paper mill, one kind of paper sludge from Fujian Qingshan paper mill, and one kind of paper sludge from Fujian Zhongzhu paper mill. The results show that there are different amounts of metal elements in the 4 kinds of paper sludge including poisonous metal elements, such as Cr, etc, metal element which is poisonous when excessive, such as Fe, etc, and P and K which are beneficial for plant growth Al and Ca contents are maximal. The recovery ratio for Fujian Zhongzhu paper mill obtained by standard addition method is 94.4%-107.3%. Heavy metal elements content lower than the national standard GB/4284-84 "Control standards for pollutions in sludge form agricultural use". The order of heavy metal elements content is paper sludge from Fujian Zhongzhu paper mill

[Determination of lignin distribution during ageing of bamboo culms (Phyllostachys pubescens) with visible-light spectrophotometry].

The lignin distribution in different anatomical regions of developing moso bamboo Phyllostachys pubescens f. lutea Wen was investigated by means of optical microscope and visible-light microspectrophotometry coupled with the Wiesner and Maule reaction. The lignin is widely distributed in different tissues, in which there is a difference in lignin content between different ages, tissues and anatomical regions. Guaiacyl lignin and Syringyl lignin unit can be found in cell wall of fibre, parenchyma and vessel. Lignin content of secondary wall, cell corner and compound middle lamellae of fibre increased gradually within 12 months, then almost remained in the same level or decreased slowly in the culms with an age from 12 to 78 months. The lignification rate in secondary wall, cell corner and compound middle lamellae of fibre changed with age until they reached a relative steady value. There is no regular variation in lignin content with different radial location of culms and different location in fibre strands within one age. The secondary wall, compound middle lamellae of parenchyma and vessel secondary wall lignified rapidly within 12 months, and then changed slowly.

[Comparison of four kinds of measurement techniques for wood microfibril angle].

X-ray diffraction technique, pit aperture observing technique, polarized light microscope technique and near infrared spectrum technique were used separately to test the wood microfibril angle of Chinese fir, and the results were as follows: For the identical tree of Chinese fir, the average microfibril angle obtained by the polarized light microscope technique was the biggest, followed by those obtained by X-ray diffraction technique, and then by polarized light microscope technique, but the difference in the average microfibril angle was not significant. For the different annual rings, the microfibril angle obtained by X-ray diffraction technique became the biggest after the 20th annual ring, the fluctuation of the microfibril angle got by the pit aperture observing technique were big, but the fluctuation got by the polarized light microscope technique was just the reverse. The measurement value curves got by the three techniques were fitted well, and the difference in the average microfibril angle was not significant between different annual rings. For the microfibril angle of the same annual ring, the difference between the maximum and the minimum value tested by the polarized light microscope technique was less than 4 degrees, but the difference tested by the pit aperture observing technique achieved 21.53 degrees, and the standard deviation achieved 4.75. The near infrared spectrum and the Xray diffraction techniques were all called nondestructive testing techniques. The model set up by the two techniques was very good because of its high prediction and repeatability, and the model was also good for online analysis. The R2 of calibration model and tested model achieved 0.81 and 0.75 respectively,and the standard error of calibration and prediction were 1.79 and 2.02 respectively. In addition, the near infrared spectrum technique could be also used with the other three techniques to predict the wood microfibril angle, showing the superiority of the near infrared spectrum technique. Meanwhile, the advantages and shortcomings were analyzed for the four kinds of measurement techniques.

[FTIR spectroscopic studies of the photo-discoloration of Chinese fir].

Wood or wood products undergo rapid degradation of surface characteristics and quality indicated by changes in wood color during outdoor exposure owing to a combination of various weathering factors, which may result in significant reduction in utilization values of wood. In the present study, photodegradation of wood surfaces of Chinese fir (Cunninghamia lanceolata) was carried out by a Xenon test chamber which can simulate sunlight irradiation. A Fourier transform infrared (FTIR) spectroscopy technique was used to study chemical changes caused by irradiation during photo-discoloration of wood surfaces, and the relationship between the changes in color and chemical composition was established. Results indicated that, during the process of irradiation, the intensity of absorption bands at 1512, 1462, 1269 and 1227 cm(-1) decreased significantly, accompanied by a successive increase in the intensity of band at 1720-1735 cm(-1). Lignin was the most sensitive component to the degradation process and underwent severe photodegradation during the process of irradiation. This was accompanied by formation of new carbonyl compounds, which indicated the photo-oxidation of wood surfaces. In the initial 80 h of irradiation, the degradation of lignin and formation of carbonyl groups were intense, and then became insignificant in longer exposure duration. Degradation of polysaccharides (cellulose and hemicellulose)also occurred during the process. Overall, color changes (deltaE*) were correlated well with the degradation of lignin and relative increase in the content of carbonyl groups during the process of irradiation.

[Study of the Eucalyptus and Poplar by generalized two-dimensional infrared correlation spectroscopy].

Poplar and Eucalyptus were identified fast by Fourier transform infrared spectroscopy (FTIR) combined with two-dimensional correlation spectroscopy (2D) in the present paper. The two kinds of wood were similar to each other in one-dimensional IR spectra but quite different in 2D FTIR spectra. In the range between 800 and 1500 cm(-1), they are similar and three strong auto-peaks were aroused around 1221, 954 and 879 cm(-1) in synchronous spectrum and four weak auto-peaks were aroused around 1470, 1150, 1105 and 1008 cm(-1), respectively. In the range between 1500 and 1800 cm(-1), one strong auto-peak appeared with Poplar around 1665 cm(-1) and one weak auto-peak appeared around 1600 cm(-1) in synchronous spectrum. They formed one pair of cross-peaks, whereas three auto-peaks not only at 1650 cm(-1) but also at 1725 and 1600 cm(-1) appeared with Eucalyptus and they became one 3 X 3 peak cluster. In addition, Eucalyptus has two weak auto-peaks at 1580, 1510 cm(-1) and four negative cross-peaks at (1725 and 1580 cm(-1), (1650 and 1580 cm(-1)), (1600 and 1580 cm(-1)) and (1510 and 1580 cm(-1)) and three positive cross-peaks at (1725 and 1510 cm(-1)), (1650 and 1510 cm(-1)) and (1600 and 1510 cm(-1)), respectively, which suggests that corresponding absorbance bands of Eucalyptus are more susceptive to the thermal perturbation than that of Poplar. The difference of 2D correlation between Eucalyptus and Poplar was obvious. The results proved that 2D correlation spectra could enhance the resolution of infrared spectra and increase the capacity of identification, which make it a powerful, rapid and new approach to identifying Eucalyptus and Poplar.

[Influence of sample surface roughness on mathematical model of NIR quantitative analysis of wood density].

Near infrared spectroscopy is widely used as a quantitative method, and the main multivariate techniques consist of regression methods used to build prediction models, however, the accuracy of analysis results will be affected by many factors. In the present paper, the influence of different sample roughness on the mathematical model of NIR quantitative analysis of wood density was studied. The result of experiments showed that if the roughness of predicted samples was consistent with that of calibrated samples, the result was good, otherwise the error would be much higher. The roughness-mixed model was more flexible and adaptable to different sample roughness. The prediction ability of the roughness-mixed model was much better than that of the single-roughness model.

[Rapid prediction of annual ring density of Paulownia elongate standing tress using near infrared spectroscopy].

Rapid prediction of annual ring density of Paulownia elongate standing trees using near infrared spectroscopy was studied. It was non-destructive to collect the samples for trees, that is, the wood cores 5 mm in diameter were unthreaded at the breast height of standing trees instead of fallen trees. Then the spectra data were collected by autoscan method of NIR. The annual ring density was determined by mercury immersion. And the models were made and analyzed by the partial least square (PLS) and full cross validation in the 350-2 500 nm wavelength range. The results showed that high coefficients were obtained between the annual ring and the NIR fitted data. The correlation coefficient of prediction model was 0.88 and 0.91 in the middle diameter and bigger diameter, respectively. Moreover, high coefficients of correlation were also obtained between annual ring density laboratory-determined and the NIR fitted data in the middle diameter of Paulownia elongate standing trees, the correlation coefficient of calibration model and prediction model were 0.90 and 0.83, and the standard errors of calibration (SEC) and standard errors of prediction(SEP) were 0.012 and 0.016, respectively. The method can simply, rapidly and non-destructively estimate the annual ring density of the Paulownia elongate standing trees close to the cutting age.

[Discrimination of wood biological decay by soft independent modeling of class analogy (SIMCA) pattern recognition based on principal component analysis].

Wood, as a biomass materials, tends to be attacked by microorganisms, and its structure could be rapidly destroyed by biological decay. Therefore, it's significant to rapidly and accurately detect or identify biological decay in wood. Recently, extensive research has demonstrated that near infrared spectroscopy (NIR) and soft independent modeling of class analogy (SIMCA) can be used to discriminate or detect a wide variety of food, medicine and agricultural products. The use of NIR coupled with principal component analysis (PCA) and SIMCA pattern recognition to detect wood biological decay was investigated in the present paper. The results showed that NIR spectroscopy coupled with SIMCA pattern recognition could be used to rapidly detect the biological decay in wood. The discrimination accuracy by the SIMCA model based on the training set for the non-decay, white-rot and brown-rot decay samples were 100%, 82. 5% and 100%, respectively; and that for the samples for the test set were 100%, 85% and 100%, respectively. However, some white-rot decay samples were mis-discriminated as brown-rot decay, for which the main reasons might be that the training set does not have enough typical samples, and there's a slight difference between white-rot and brown-rot decay during the early stage of decay.

[Effects of spectral pretreatment on the prediction of crystallinity of wood cellulose using near infrared spectroscopy].

The crystallinity of wood has an important effect on the physical, mechanical and chemical properties of cellulose fibers. The aims of this study were to investigate the ability of near infrared spectroscopy (NIR) to predict the crystallinity of wood cellulose and the effect of spectral pretreatment on the prediction of crystallinity in wood cellulose using near infrared spectroscopy (NIR). Near infrared diffuse reflectance spectra were collected from wood powder with a fiber-optical probe and the crystallinity of wood was determined by X-ray diffractometer (XRD) in this experiment. The results showed that near infrared spectroscopy coupled with partial least square (PLS) regression could be correlated with the crystallinity of plantation wood, and the ability of NIR prediction based on original spectra was better than that based on the first derivative or second derivative treated spectra. There was a significant correlation between NIR spectra and XRD determined crystallinity with a correlationcoefficient of 0.950 and a low RMSEP. Near infrared spectroscopy coupled with multivariate data anlaysis has proven to be an accurate and fast method for rapid prediction of wood crystallinity.

[The analysis of wood microfibril angle by near infrared spectroscopy and X-ray diffractometry].

In the present paper, near infrared (NIR) spectroscopy and X-ray diffractometry were used to rapidly predict the microfibril angle (MFA). MFA is one of the most important factors affecting wood properties. Wood resource utilization and tree improvement programs require cost-effective methods for the rapid analysis of thousands of samples. In the experiment, the average MFA of each sample were rapidly measured by X-ray scanning diffractometry. Then, the PLS model was built between NIR data and MFA by the X-ray measured. As a result, a very strong linear relationship has been found between NIR spectra fitted and X-ray measured, and the coefficients (r2) of calibration and prediction models were 0.867 and 0.816 respectively.