Hydrogen peroxide modulates lignin and silica deposits in sorghum roots

AbstractSilica aggregates in the root endodermis of grasses. Application of Si to roots is associated with variations in the balance of reactive oxygen species (ROS), increased tolerance a broad range of stresses affecting ROS levels, and early lignin deposition. In sorghum (Sorghum bicolor L.), silica aggregation is patterned in an active silicification zone (ASZ) by a special type of lignin. Since lignin polymerization is mediated by ROS, we studied the formation of root lignin and silica under varied conditions of ROS and specifically hydrogen peroxide (H2O2). Sorghum seedlings were grown hydroponically and supplemented with Si, H2O2, and KI. Lignin and silica deposits in the endodermis were studied by optical, scanning electron, and Raman microscopies. Cell wall composition was quantified by thermal gravimetric analysis. We found that silica aggregation was catalyzed by lignin modified by carbonyls. These residues were available for silica nucleation only within 2 hours of their deposition. The endodermal H2O2 concentration regulated the intensity but not the pattern of ASZ lignin deposits. Our results show that ASZ lignin is necessary for root silica aggregation in sorghum, and that silicification is enhanced under oxidative stress as a result of increased deposition of the ASZ lignin.One sentence summaryLignin with carbonyl modifications is patterned by the activity of H2O2 to nucleate silica aggregations in sorghum roots.

Synthesis of Novel Carbon Spheres and Study on Graphitization Process

10.4028/www.scientific.net/amr.634-638.2293 ◽

2013 ◽

Vol 634-638 ◽

pp. 2293-2296

Author(s):

Ai Li Ma ◽

Cheng Qian Li ◽

Wu Qing Du ◽

Jie Chang

Keyword(s):

High Temperature ◽

Microwave Plasma ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Carbon Spheres ◽

X Ray Diffraction ◽

X Ray ◽

Cvd Method ◽

Graphitization Degree ◽

In this paper, carbon spheres were synthesized by CVD method. These carbon spheres exhibit diameters of about 200 nm. Thermal gravimetric analysis indicated the good stability in high temperature of the carbon spheres. The products were treated by microwave plasma and high temperature vacuum heat treatments respectively. The products were characterized by X-ray diffraction, Raman spectroscopy and Field Emission Scanning Electron Microscope. The study indicated that the original products, with perfect morphology and low graphitization degree, were converted to crystal. The different techniques were considered for the influence on the graphitization degree.

The Utilization of Recycled Newspaper in the Production of Cellulose Microfiber

10.4028/www.scientific.net/amr.1133.644 ◽

2016 ◽

Vol 1133 ◽

pp. 644-648 ◽

Cited By ~ 1

Author(s):

Mohamad Azuwa Mohamed ◽

Wan Norharyati Wan Salleh ◽

Juhana Jaafar ◽

Ahmad Fauzi Ismail

Keyword(s):

Electron Microscopy ◽

Cost Effective ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

X Ray Diffraction ◽

X Ray ◽

Reinforcement Material ◽

Cellulose Microfibers ◽

Thermal Stability Of ◽

Cellulose microfibers (CMF) were produced by utilizing recycled newspaper paper (RNP) as starting material. This approach is considered as green since recycling newspaper leads to the environment preservation and also cost-effective. The effect on the structural properties of cellulose produced at different stage of pretreatment were investigated by using Fourier transform infrared (FTIR), Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Thermal gravimetric analysis (TGA). The FTIR and SEM demonstrate that the hemicellulose and lignin was successfully removed from the structure of the CMF. XRD and TGA results revealed that the different step of pretreatment was increased the crystallinity and thermal stability of CMF increased gradually. The improvement in CMF crystallinity has improved its thermal properties which is important in the field of reinforcement material.

Acoustic Properties of a New Composite Material Obtained from Feather Flour and Recycled Polypropylene

Materiale Plastice ◽

10.37358/mp.21.4.5534 ◽

2022 ◽

Vol 58 (4) ◽

pp. 84-93

Author(s):

Mirela Alina Constantin ◽

Lucian Alexandru Constantin ◽

Sebastian Aradoaei ◽

Mihaela Aradoaei ◽

Mihai Bratu ◽

...

Keyword(s):

Electron Microscopy ◽

Natural Fibers ◽

Adsorption Properties ◽

Point Of View ◽

Acoustic Properties ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Recycled Polypropylene ◽

Sustainable Materials ◽

Sustainable materials made from recycled materials are an alternative to traditional materials (synthetic ones) and present a lower environmental impact. Due to the fact that natural fibers were successfully used to produce environmentally friendly sound adsorbing materials, biocomposites made from recycled polypropylene (PPR), feathers flour (FF) with / without compatibilizers (C) were obtained and characterized from the point of view of their acoustical behavior. Obtained materials were characterized also from the morphological and compositional point of view by scanning electron microscopy and thermal gravimetric analysis. All tested samples presented sound adsorption properties but the best results were obtained for the biocomposites with FF content of 10%-20%.

Evaluation of LDPE Degradation Under Controlled Composting

Nature Environment and Pollution Technology ◽

10.46488/nept.2021.v20i03.041 ◽

2021 ◽

Vol 20 (3) ◽

Author(s):

S. Singh ◽

S. Shankar ◽

Shikha .

Keyword(s):

Major Change ◽

Natural Ecosystem ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Sem Images ◽

X Ray ◽

Polyethylene Films ◽

The compost burial test was performed to determine the degradation of commercially available low-density polyethylene in natural compost for a period of six months. Biodegradability of polyethylene films in compost was monitored using scanning electron microscopy (SEM), Energy dispersive X-Ray, Fourier transform infrared spectroscopy (FTIR), X-Ray diffraction (XRD), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and weight reduction analysis. After six months of compost exposure, a major change over the surface of LDPE was observed. SEM images clearly showed the exfoliation and cracks on the film leading to degradation. The other analysis also showed a change in the thermal properties and crystallinity of the LDPE films. The composting method could prove to be the reliable and ecological method of degrading plastic waste without hindering the natural ecosystem.

Coaxial Poly (Phenylene Vinylene)/Carbon Nanotube Nanocomposites

10.4028/www.scientific.net/amr.1035.325 ◽

2014 ◽

Vol 1035 ◽

pp. 325-329

Author(s):

Yi Zhou ◽

Xiao Ping Wang ◽

Wen Yi Li ◽

Hui Li ◽

Ming Tian ◽

...

Keyword(s):

Electrode Materials ◽

Multiwall Carbon Nanotubes ◽

Phenylene Vinylene ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Chemical Polymerization ◽

Core Shell Structure ◽

Multiwall Carbon ◽

Coaxial nanocomposites were prepared by in–situ chemical polymerization of 4– dibromomethyl–2,5–2–octyloxy phenylene in the presence of multiwall carbon nanotubes. The morphology, microstructure and thermal and electrochemical properties of the resulting nanocomposites were investigated by scanning electron microscopy, Fournier infrared spectroscopy, thermal gravimetric analysis and cyclic voltammetry. The results indicated that the nanocomposites with uniform core-shell structure exhibited higher thermal stability than neat poly (phenylene vinylene). Furthermore, energy storage ability of these coaxial nanocomposites as electrode materials for supercapacitor was evaluated.

The Ultimate Biodegradation of the Starch Based Biodegradable Plastics

10.4028/www.scientific.net/amr.506.327 ◽

2012 ◽

Vol 506 ◽

pp. 327-330 ◽

Cited By ~ 1

Author(s):

Parichai Intaraksa ◽

Yositar Rudeekit ◽

Pongsaks Siriyota ◽

P. Chaiwutthinan ◽

M. Tajan ◽

...

Keyword(s):

Aerobic Biodegradation ◽

Poly Lactic Acid ◽

Lag Phase ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Biodegradation Rate ◽

Testing Period ◽

Good Accordance ◽

Ft Ir ◽

The objective of this work was to investigate the ultimate aerobic biodegradation of poly (lactic acid) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT), with and without the starch according to ISO14855-1: 2004. The degree of biodegradation for 120 days of PLA, PLA/starch (50:50), PBAT and PBAT/starch (50:50) were 85.75%, 93.60%, 23.71% and 73.32%, respectively. The degree of biodegradation of cellulose was 70.20% under the same conditions. For PLA, a lag phase was observed during the first twenty days of the testing. This result indicated that there was no ultimate biodegradation occurred at the beginning of testing period of PLA. However, no lag phase was observed in the biodegrability testing of the PLA/starch (50:50), PBAT and PBAT/starch (50:50). Moreover, the addition of starch into the polymers leads to higher biodegradation rate of the materials. Finally, the biodegradation results were confirmed by thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). It was found that the results of TGA, FT-IR and SEM were in good accordance with the biodegradation results.

Improving the Performance of Intumescent Flame Retarded Polypropylene with Nano-ZrO2

10.4028/www.scientific.net/amr.150-151.32 ◽

2010 ◽

Vol 150-151 ◽

pp. 32-35

Author(s):

Xin Long Wang ◽

Liang Hu Wu

Keyword(s):

Cone Calorimeter ◽

Flame Retardants ◽

Synergistic Effects ◽

Flame Retardance ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Flame Retarded ◽

Synergistic Agent ◽

Intumescent Flame Retardants ◽

Melamine polyphosphate (MPP) and pentaerythritol(PTL) were used as intumescent flame retardants to improve the flame retardance of polypropylene(PP). As a synergistic agent, nano-ZrO2 was incorporated into the composites at different proportions. The synergistic effects of nano-ZrO2 were studied by cone calorimeter tests and thermal gravimetric analysis (TGA). Based on scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR), it was evident that nano-ZrO2 efficiently promoted the formation of charred layers with phosphocarbonaceous structures and enhanced the flame retardance of the composites.

Effects of surfactants on the properties of epoxy/graphene nanocomposites

Journal of Reinforced Plastics and Composites ◽

10.1177/0731684418765369 ◽

2018 ◽

Vol 37 (14) ◽

pp. 960-967 ◽

Cited By ~ 3

Author(s):

Jiacheng Wei ◽

Mohd Shahneel Saharudin ◽

Thuc Vo ◽

Fawad Inam

Keyword(s):

Electron Microscopy ◽

Sodium Dodecyl Sulphate ◽

Sodium Dodecyl ◽

Gum Arabic ◽

Mechanical Analysis ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Graphene Nanocomposites ◽

The Matrix ◽

Recently, graphene has attracted extensive research interests due to its superior mechanical, electrical and thermal performance. Small loadings of graphene can increase the properties of epoxy significantly. However, because of the large surface area of graphene, it is a challenge to disperse graphene in liquid epoxy. Strong van der Waals force causes reaggregation of graphene in the matrix. As commonly used surfactants, sodium dodecyl sulphate and gum arabic have been used a lot to de-bundle graphene, however, their dispersing efficiencies for graphene in epoxy matrix is unknown. Therefore, to evaluate their dispersing efficiencies, epoxy/graphene nanocomposites had been made and mechanical properties, dynamic mechanical analysis, thermal gravimetric analysis and scanning electron microscopy tests of nanocomposites had been conducted. The results show that the properties of nanocomposites had been enhanced largely after using sodium dodecyl sulphate and gum arabic. Sodium dodecyl sulphate shows higher dispersing effectiveness than gum arabic.

Synthesis and Properties of Poly(3,4-Ethylenedioxythiophene) via Solid-State Polymerization

10.4028/www.scientific.net/amr.306-307.261 ◽

2011 ◽

Vol 306-307 ◽

pp. 261-264

Author(s):

Shu Ai Chen ◽

Jing Kun Xu ◽

Dan Hua Zhu ◽

Xue Min Duan

Keyword(s):

Crystal Structure ◽

Electron Microscopy ◽

Solid State ◽

Main Chain ◽

Conductivity Measurement ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

Electrical Conductivity Measurement ◽

Solid State Polymerization ◽

Conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) has been synthesized by solid-state polymerization of 2,5-diiodo-3,4-ethylenedioxythiophene under normal conditions. The resulting iodine-doped PEDOT is completely insoluble in common organic solvents and retained partial crystal structure of monomer as indicated by scanning electron microscopy. Electrical conductivity measurement showed that PEDOT exhibited conductivity in the range of 0.16–0.23 S/cm (pressed powder pellet) with temperature dependence. Thermogravimetric and differential thermal gravimetric analysis of PEDOT indicated that its main chain was stable up to ca. 200 °C.

Avaliação do bagaço de cana natural e modificado como potencial sorvente de óleo vegetal

Revista Verde de Agroecologia e Desenvolvimento Sustentável ◽

10.18378/rvads.v11i4.4172 ◽

2016 ◽

Vol 11 (4) ◽

pp. 129

Author(s):

Viviane Vasques da Silva Guilarduci ◽

Honória Fátima Gorgulho ◽

Patrícia Benedini Martelli ◽

Vanessa Soares dos Santos ◽

William Graciliano Corrêa

Keyword(s):

Electron Microscopy ◽

Acetic Anhydride ◽

Vegetable Oil ◽

Sugarcane Bagasse ◽

Gravimetric Analysis ◽

Thermal Gravimetric ◽

X Ray Diffraction ◽

X Ray ◽

Oily Water ◽

O óleo e a gordura vegetal residual, utilizados para a preparação de alimentos representam um perigoso poluente para as águas de córregos e rios. Um dos métodos mais utilizados nas últimas décadas para limpeza da água oleosa é a aplicação de biossorventes, pois apresentam facilidade para remoção e recuperação do óleo. Neste sentido, o objetivo deste trabalho foi determinar a influência das modificações do bagaço de cana com anidrido acético (acetilação) e com 3-aminopropiltrietoxisilano (silanização) sob a sorção de óleo vegetal. A modificação das fibras foi avaliada pelas técnicas de espectroscopia no infravermelho com transformada de Fourier (FTIR), análise termogravimétrica (TG), difração de raios X, microscopia eletrônica de varredura (MEV) e análise de área superficial e porosidade. Os resultados obtidos indicaram maior sorção de óleo vegetal para o bagaço de cana modificado com anidrido acético (BCA), 667 mg.g-1, seguido pelo bagaço de cana sem modificação (BCN) com sorção de 576 mg.g-1. O bagaço de cana modificado com 3-aminopropiltrietoxisilano (BCS) apresentou menor sorção, 425 mg.g-1, o que foi atribuído à sua maior hidrofilicidade.Evaluation of natural and modified sugarcane bagasse as sorbent of vegetable oil Abstract: The oil and the residual vegetable fat, used for the preparation of foods represent a dangerous pollutant for the waters of streams and rivers. One of the most used methods in the last decades for cleaning the oily water is the application of biosorbents, since they are easy to remove and recover the oil. In this sense, the purpose of this work was to determine the influence of the modifications of sugarcane bagasse with acetic anhydride (acetylation) and with 3-aminopropyltriethoxysilane (silanization) under sorption of vegetable oil. The BCN and the grafted products were further characterized by FTIR spectroscopy, thermal gravimetric analysis, X-ray diffraction, scanning electron microscopy and analysis of surface area and porosity. The results showed higher sorption of vegetable oil for the acetic anhydride-modified sugarcane bagasse (BCA), 667 mg.g-1, followed by sugarcane bagasse without modification (BCN) with sorption of 576 mg.g-1. The cane bagasse modified with 3-aminopropyltriethoxysilane (BCS) presented lower sorption, 425 mg.g-1, which was attributed to its greater hydrophilicity.