scholarly journals Chemical and Structural Characterization of Maize Stover Fractions in Aspect of Its Possible Applications

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1527
Author(s):  
Magdalena Woźniak ◽  
Izabela Ratajczak ◽  
Dawid Wojcieszak ◽  
Agnieszka Waśkiewicz ◽  
Kinga Szentner ◽  
...  

In the last decade, an increasingly common method of maize stover management is to use it for energy generation, including anaerobic digestion for biogas production. Therefore, the aim of this study was to provide a chemical and structural characterization of maize stover fractions and, based on these parameters, to evaluate the potential application of these fractions, including forbiogas production. In the study, maize stover fractions, including cobs, husks, leaves and stalks, were used. The biomass samples were characterized by infrared spectroscopy (FTIR), X-ray diffraction and analysis of elemental composition. Among all maize stover fractions, stalks showed the highest C:N ratio, degree of crystallinity and cellulose and lignin contents. The high crystallinity index of stalks (38%) is associated with their high cellulose content (44.87%). FTIR analysis showed that the spectrum of maize stalks is characterized by the highest intensity of bands at 1512 cm−1 and 1384 cm−1, which are the characteristic bands of lignin and cellulose. Obtained results indicate that the maize stover fraction has an influence on the chemical and structural parameters. Moreover, presented results indicate that stalks are characterized by the most favorable chemical parameters for biogas production.

Author(s):  
A. F. Afolabi ◽  
S. S. Oluyamo ◽  
I. A. Fuwape

In this research, nanocellulose is isolated from Moringa oleifera seed using acid hydrolysis and the structural properties were determined. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy were used for the characterization of the isolated nanocellulose. The most noticeable peak is observed at  and the value of the crystallinity index () from the XRD pattern is 63.1%. The calculated values of  hydrogen bond intensity (HBI), lateral order index (LOI) and total crystalline index (TCI) are 0.93, 1.17and 0.94 respectively exhibited high degree of crystallinity and well arranged cellulose crystal structure. The isolated nanocellulose has an average length and diameter of 14.3 and 36.33 respectively. Furthermore, the FTIR peaks revealed the presence of C-H bending, C-O stretching and O-H stretching functional groups.


Author(s):  
A. F. Afolabi ◽  
S. S. Oluyamo ◽  
I. A. Fuwape

The use of Moringa oleifera seeds for purifying water has been attempted locally in various forms without putting scientific potency of the material into consideration. The cellulose sample isolated from Moringa {oleifera} seed was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The value of the crystallinity index (CIr ) from the XRD pattern is 63.1%. The high degree of crystallinity obtained is attributed to the high percentage of crystallinity index, CIr (i.e. 63.1%). The morphology revealed aggregates of conical and needle-like structure. The FTIR revealed O-H stretching, C-H stretching vibration, and C=O bond stretching functional groups. These characteristics are indicative of the potential of the material in water purification.


2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Milan Melnik ◽  
Peter Mikuš ◽  
Clive E. Holloway

AbstractThis review classifies and analyzes over fifty heterohepta- and heterooctanuclear platinum clusters. There are eight types of metal combinations in heteroheptanuclear: Pt6M, Pt5M2, Pt4M3, Pt3M4, Pt2M5, PtM6, Pt3Hg2Ru2 and Pt2Os3Fe2. The seven metal atoms are in a wide variety of arrangements, with the most common being one in which the central M atom (mostly M(I)) is sandwiched by two M3 triangles. Another arrangement often found is an octahedron of M6 atoms asymmetrically capped by an M atom. The shortest Pt-M bond distances (non-transition and transition) are 2.326(1) Å (M = Ga) and 2.537(6) Å (M = Fe). The shortest Pt-Pt bond distance is 2.576(2) Å.In heterooctanuclear platinum clusters there are eight types of metal combinations: Pt6M2, Pt4M4, Pt3Ru5, Pt2M6, PtM7, Pt2W4Ni2, PtAu6Hg and PtAu5Hg2. From a structural point of view, the clusters are complex with bicapped octahedrons of eight metal atoms prevailing. The shortest Pt-M bond distances (non-transition and transition) are 2.651(3) Å (M = Hg) and 2.624(1) Å (M = Os). The shortest Pt-Pt bond distance is 2.622(1) Å. These values are somewhat longer than those in the heteroheptanuclear clusters. Several relationships between the structural parameters were found, and are discussed and compared with the smaller heterometallic platinum clusters


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongfang Qian ◽  
Zhen Zhang ◽  
Laijiu Zheng ◽  
Ruoyuan Song ◽  
Yuping Zhao

Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL) blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θof 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.


1997 ◽  
Vol 306 (2) ◽  
pp. 198-204 ◽  
Author(s):  
A.A. Darhuber ◽  
J. Stangl ◽  
V. Holy ◽  
G. Bauer ◽  
A. Krost ◽  
...  

2011 ◽  
Vol 396-398 ◽  
pp. 1180-1183
Author(s):  
He Ping Li ◽  
Hu Qiang Lv ◽  
Yao Zhang ◽  
Yong Zhe Yang

In the normal pressure and presence of catalyst, a novel composite modified starch or functional surfactant was synthesized by using the cassava starch as the main feedstock through the alkalization, etherification and oxidation etc.. The degree of substitution was up to 1.21. Based on the orthogonal experiment and computer-aid methods, the optimum conditions were resulted as follows: the mass fractions(vs. dry starch) of chloroacetic acid, catalyst and oxidant were 32%, 0.01% and 1.14% respectively, and the reaction temperature of etherification was at 50°C for 4.1h. The structural characterization of the composite modified starch was determined by IR and X-ray diffraction.


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