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Investigation of biomass surface modification using non-thermal plasma treatment

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Plasma Science and Technology 2018年第11期20卷 101-107页

作者：林木森 Ahmad Zulazlan Shah ZULKIFLI TNB Research Sdn. Bhd. Research Institution Area 43000 Kajang Selangor Malaysia

The effects of non-thermal plasma （NTP） treatment on biomass in the form of pulverized palmbased empty fruit bunches （EFB） are investigated. Specifically, this study investigates the effects of NTP treatment on the surface reactivity, morphology, oxygen-to-carbon （O/C） ratio of the EFB at varying treatment times. The surface reactivity is determined by the reaction of antioxidant functional groups or reactive species with 2,2-diphenyl-l-picrylhydrazyl （DPPH）. By measuring the concentration of the DPPH with a spectrophotometer, the change in the amount of antioxidant functional groups can be measured to determine the surface reactivity. The reactions of the various lignin components in the EFB with respect to the NTP treatment are discussed by qualitatively assessing the changes in the Fourier transform infrared （FTIR） spectra. The surface morphology is examined by a scanning electron microscope. To determine the amount of oxygen deposited on the EFB by the air-based NTP treatment, the oxygen and carbon contents are measured by an energy dispersive x-ray detector to determine the O/C ratio. The results show that the NTP reactor produced reactive species such as atomic oxygen and ozone, increasing the surface reactivity and chemical scavenging rate of the EFB. Consequently, the surface morphology changed, with an observed rougher surface from the images of the EFB samples. The change in the appearance of the surface is accompanied by a high O/C ratio, and is caused by reactions of certain components of lignin due to the NTP treatment, The lignin component that was modified is believed to be syringyl, as the syringyl portion in the lignin of EFBs is higher compared to the other components. Syringyl components are detected in the range of F-FIR wavenumbers of 1109-1363 cm-1. With increasing NTP treatment times, the absorbance （of the peaks in the PTIR spectra） for syringyl related C-H and lignin associated C=C bonds decreases as the syringyl decomposes. The resulting re

关键词： biomass surface modification empty fruit bunch low temperature plasma lignin components syringyl

Enhancement of the flux for polypropylene hollow fiber membrane in a submerged membrane-bioreactor by surface modification

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Journal of Environmental Sciences 2006年第6期18卷 1050-1055页

作者： YU Hai-yin LEI Hao XU Zhi-kang Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education of China Institute of Polymer Science Zhejiang University Hangzhou 310027 China School of Chemistry and Materials Science Anhui Normal University Wuhu 241000 China

To improve its limiting flux and antifouling characteristics in a submerged membrane-bioreactor （SMBR） for wastewater treatment, polypropylene hollow fiber microporous membrane （PPHFMM） was surface-modified by the plasma-induced immobilization of poly （N-vinyl-2-pyrrolidone）（PVP） and the plasma treatment with different gases respectively. Attenuated total reflection-Fourier transform infrared spectroscopy （FT-IR/ATR）, X-ray photoelectron spectroscopy （XPS） and field emission scanning electron microscope （FE-SEM） were used to characterize the structural and morphological changes on the membrane surface. Water contact angle was measured by the sessile drop method. It was found that the water contact angle was 128.8, 72.3, 62.7, 74.4, 79.1, 86.3, and 71.3° for the nascent, PVP-immobilized, air, 02, Ar, CO2 and H2O plasma treated PPHFMM, respectively. The SMBR was operated at fixed transmembrane pressure to determine the limiting flux for the PPHFMM before and after surface modification. Results showed that the limiting flux appeared to be 103, 159, 117, 133, 136, 121 and 152 L/（m^2· h） for the nascent, PVP-immobilized, air, O2, At, CO2 and H2O plasma treated PPHFMM, respectively. After continuous operation for about 50 h in the SMBR, the antifouling characteristics were improved to some extent.

关键词： surface modification polypropylene hollow fiber microporous membrane limiting flux submerged membrane-bioreactor antifouling characteristics

Characteristics of Coaxial Dielectric Barrier Discharge at an Atmospheric Pressure with a Swirling Gas Argon/Oxygen Mixture for the surface modification of Polyester Fiber Cord

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Plasma Science and Technology 2010年第5期12卷 601-607页

作者：徐金洲钟平李嘉灵林捷刁颖张菁 Department of Applied Physics College of Science Donghua University

Abstract A newly developed coaxial dielectric barrier discharge reactor with a length of 1000 mm at an atmospheric pressure was used for plasma treatment of polyester fiber cord in a roll-to-roll manner. In this reactor, swirling mixture gases of oxygen of about 1% and argon with a flow rate of 1.5 L/rain to 2.7 L/min ensured the gas usage sparing, discharge uniformity and efficient fiber surface modification. The water contact angle and surface morphology of the treated fiber were measured. The results show that the surface oxygenation is mainly responsible for the wettability improvement of the fiber cord when passing through the plasma zone at a linear speed of 3 m/min to 8 m/rain. The specimens of modified-polyester fiber reinforced rubber composite were also prepared for the interracial shear strength tests. Furthermore, the effect of adding oxygen into argon discharge on the fiber surface oxidation was correlated with optical emission spectroscopy. Finally, the effect of adding oxygen into argon discharge on the kinetic processes of the active species generation were also analyzed.

关键词： coaxial dielectric barrier discharge polyester fiber surface modification

surface modification of barite nanoparticles using stearate

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Journal of Shanghai University(English Edition) 2009年第4期13卷 296-300页

作者：李琳琳杭建忠施利毅 School of Environmental and Chemical Engineering Shanghai University School of Materials Science and Engineering Shanghai University Nano Science and Technology Research Center Shanghai University

In this study, the barite nanoparticles were successfully modified with stearate and the influence of stearate addition on the performance of barite nanoparticles was systematically investigated. The products were characterized by activating factor analysis, contact angle test, surface energy calculation, sedimentation rate calculation, rheological measurement, and FT-IR analysis, etc. As the quantity of added stearate increased, both the activating factor and contact angle of barite nanoparticles increased first then decreased. When the stearate content was 5% of the mass of barite nanoparticles, the activating factor and water contact angle of modified particles reached maximum value, 97% and 126% respectively. At this time, the sedimentation rate reached minimum, and so did the surface energy. The rheological test reveals that the viscosity of modified barite nanoparticles/petronol system decreases greatly, indicating the surface performance of barite nanoparticles has changed from hydrophilicity to lipophilicity after modification. C=O and COO stretching vibration peaks were found in the FT-IR spectra, which proves that the stearate has combined onto the surface of barite nanoparticles. Finally, according to the zeta potential result of unmodified barite, the possible modification mechanism was provided.

关键词： nano barite surface modification stearate

Comparison study of two aldehyde group finishing agents in surface modification of up-conversion luminescence materials

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Rare Metals 2008年第2期27卷 127-130页

作者： CUI Lili FAN Huili XIAO Junping XU Xiaowei Department of Chemistry University of Science and Technology Beijing Beijing 100083 China Department of Inorganic Nonmetallic Materials University of Science and Technology Beijing Beijing 100083 China

surface modification of up-conversion luminescence materials （Na[Y0.57Yb0.39Er0.04]F4 modified by amino groups） by grafting and modifying with aldehyde groups was studied by means of Fourier transform infrared spectroscopy （FTIR）, scanning electron microscopy （SEM）, thermogravimetric analysis （TGA）, and emission spectrum （EM）. The surface modification effect was compared using two different finishhag agents, p-phthalaldehyde and glutaraldehyde. It was found that the surface of up-conversion luminescence materials could be modified by aldehyde groups of the two finishing agents, the systematic dispersibility and the thermostability of the up-conversion luminescence material modified by p-phthalaldehyde were better than those of the material modified by glutaraldehyde, and the luminous intensity of the material modified by p-phthalaldehyde was increased. The AI （the ratio of the suspended segmental quality in the specimen to the total mass of the specimen） of the material modified by p-phthalaldehyde was higher than that of the material modified by glutaraldehyde. It is obviously seen that the embellishment effect of p-phthalaldehyde as a finishing agent was better than that of glutaraldehyde. In addition, the reasons why p-phthalaldehyde is a good finishing agent are also explained.

关键词： luminescence materials up-conversion surface modification luminescence aldehyde groups

Electrochemical behavior of Cu-Zn-Al shape memory alloy after surface modification by electroless plated Ni-P

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Rare Metals 2004年第4期23卷 317-321页

作者： LIANGChenghao CHENBangyi CHENWan WANGHua SchoolofChemicalEngineering DalianUniversityofTechnologyDalian116012China

The electrochemical behavior of Cu-Zn-Al shape memory alloy (SMA) with andwithout electroless plated Ni-P was investigated by electrochemical methods, in artificial Tyrode'ssolution. The results showed that Cu-Zn-Al SMA engendered dezincification corrosion in Tyrode'ssolution. The anodic active current densities as well as electrochemical dissolution sensitivity ofthe electroless plated Ni-P Cu-Zn-Al SMA increased with NaCl concentration rising, pH of solutiondecreasing and environmental temperature uprising. X-ray diffraction analysis indicated that aftersurface modification by electroless plated Ni-P, an amorphous plated film formed on the surface ofCu-Zn-Al SMA. This film can effectively isolate matrix metal from corrosion media and significantlyimprove the electrochemical property of Cu-Zn-Al SMA in artificial Tyrode's solution.

关键词： surface modification dezincification corrosion electrochemical method Cu-Zn-Al shape memory alloy artificial Tyrode's solution electroless plated Ni-P

Effect of surface modification on Behaviors of Cerium Oxide Nanopowders

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Journal of Rare Earths 2007年第3期25卷 368-372页

作者：李梅史振学柳召刚胡艳宏王觅堂励杭泉 School of Materials Science and Engineering Beijing University of Chemical Engineering School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014010China School of Materials and Metallurgy Inner Mongolia University of Science and Technology

Study was made on the effect of surface modification on the behaviors of cerium oxide nanopowders.A surfactant-sodium dodecyl sulfate（C12H25SO4Na）was used to modify the surface of CeO2 powder *** unmodified and modified CeO2 powders were characterized by using a powder comprehensive characteristic tester,laser particle size analyzer,specific surface area tester,X-ray diffraction tester,and a scanning electron *** testing and analysis results showed that C12H25SO4Na surface modification might increase the flowability and dispersity,and decrease the specific surface area and agglomeration of CeO2 *** mechanism of the surface modification of CeO2 powder particles was also discussed.

关键词： polymeric materials cerium oxide nanopowder surface modification surfactant rare earths

STUDY ON THE surface modification OF NANO-TiO_2 BY GRAFTING PMMA/PBMA AND ITS THERMAL STABILITY

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Chinese Journal of Polymer Science 2005年第3期23卷 243-247页

作者：宇海银 Jia-shanGu JunDu Ming-yunGuan CollegeofChemistryandMaterialsScience AnhuiNormalUniversityWuhu241000China

The surface of nano-TiO_2 was encapsulated with hydroxyl-propyl-methyl cellulose(HPMC),and then cograftedwith *** of absorbing and grafting have been *** nano-TiO_2 particles were characterized byFT-IR spectra,TEM and TG *** was convinced from FT-IR studies that both methyl methacrylate(MMA)and butyl-methacrylate(BMA)were co-grafted onto the surface of nano-TiO_2 *** images show that the surface of nano-TiO_2 particles was successfully modified by a thick layer of film-like *** results demonstrate that the decompositiontemperature of HPMC-g-PMMA/PBMA,which has been grafted onto the surface of nano-TiO_2,is 56.9 K higher than that ofHPMC-g-PMMA/PBMA.

关键词： Hydroxyl-propyl-methyl cellulose Nano-TiO_2 particles surface modification Cograft polymerization Thermal stability.

Field Emission Enhancement of Carbon Nanotubes by surface modification

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Chinese Physics Letters 2007年第1期24卷 233-235页

作者：勇振中巩金龙王震霞朱志远胡建刚潘强岩 Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 Graduate School of the Chinese Academy of Sciences Beijing 100049

By employing a multi-walled carbon nanotube （MWCNT） film as the substrate, we obtain Fe tipped carbon nanorods or carbon nanoparticles grown on the outer walls of MWCNTs by combining sputtering deposition of Fe films and rf plasma enhanced chemical vapour deposition at high temperature. Scanning electron microscopy and high-resolution transmission electron microscopy are used to examine the structure of carbon nanorods and carbon nanoparticles. In addition, the formation mechanism is discussed briefly. The electron field emission tests indicate that the turn-on field （at 10μA/cm^2） of the treated MWCNT films decreases from 2.4 V/μm to O. 79 V/μm and the field emission current is relatively stable. The enhanced field enhancement factor, increasing emission densities coming from the grown nanorods and nanoparticles, and H terminated by H plasma a11 are responsible for the enhancement of the field enhancement factor.

关键词： Field Emission Enhancement multi-walled carbon nanotube (MWCNT) film surface modification