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The electric papers have a wide variety of uses like in transformers, cables and power capacitors. Each application involves different requirements related to its mechanical and electric properties. The kraft is the dielectric paper most used due its high mechanical resistance and a dielectric strength of around 5 kV/mm that is increased up to 30 kV/mm when is impregnated with mineral oil and typically has a density of 0.7, nevertheless continuous improvements in the design, for example, of power transformers raise the need to improve its electrical properties particularly those related to its relative permittivity. In this article, structural parameters such as distribution and pore size of kraft paper and theoretical analysis for possible addition of nanofillers to improve their dielectric behavior are reported. A possible and better criterion for designing transformers can be the employment of kraft paper nano-inserted with 5 % of TiO2 or BaTiO3 stew in mineral oil and immersed in natural ester liquid.

The aim of this study was to obtain the effect of drying methods on surface properties and ink penetration. Laser scanning confocal microscope (LSCM) was used in order to characterize the penetration depth through quantitative analysis. Fluorescent ink was used to observe and characterize ink penetration and distribution by LSCM. The results showed that the drying methods had an important role on the surface properties and ink penetration of coated paper. Infrared drying compared with vacuum drying and hot air drying was good to improve the paper properties, which resulted in low roughness, high gloss, low ink absorption and high paper surface efficiency. It could be concluded that infrared drying compared with vacuum drying and hot air drying resulted in the highest print density and better printability.

Tertiary treatment wascarried out to treat pulp and paper effluent from secondary treatment processby a three-dimensional electrode system equipped with modifiedbentonites as powdery electrode. The cetyl trimethylammonium bromide modified bentonite (CTAB-bent) and hydroxy-aluminum pillaredorganic bentonite (OH-Al-CTAB-bent) were synthesized and characterized by XRDand FTIR spectroscopy analysis.The impacts such as the dosage of particle electrode, electrolysis times,current density were on the COD removal efficiency and decolorization effect ofeffluent were also investigated. The results showed that the experimentscarried out by three-dimensional electrode system with OH-Al-CTAB-bent weresufficient for the COD and color removal efficiency. A current density of 30mA/cm2, electrolysis time of 40min, and the particle electrodedosage of 1.6g/L were selected as an optimum conditions that allows fast andlow cost treatment. The effluent can achieve the discharge standard of waterpollutants for pulp and paper industry (GB3544-2008) after electrolysis.

What happens in the paper surface about ink absorption is of great important for appearance of final printing. The aim of this experiment was to investigate the influence of printing pressure and printing speed on ink layer thickness transferred onto coated paper through quantitative analysis by laser scanning confocal microscope (LSCM). Meanwhile, the influence of printing pressure and printing speed on print density and print gloss were obtained. The results implied that higher printing pressure resulted in higher ink layer thickness, print density and print gloss when printing pressure is less than 700N, but higher printing speed resulted in lower ink layer thickness, print density and print gloss when printing pressure is constant. It could be concluded that the coated paper with high printing speed compared with low printing speed resulted in lower ink absorption, lower print density, lower print gloss and worse printability on the condition of same printing pressure.

The objective of this experiment was to investigate the influence of coating solid on surface properties and ink penetration and to characterize the penetration depth through quantitative analysis by laser scanning confocal microscope (LSCM). Fluorescent ink was used to observe and characterize ink penetration and distribution by LSCM. The results implied that the surface properties of coated paper could be adjusted and improved by increasing the coating solid. With the increasing of coating solid, ink penetration depth declined and ink penetration uniformity increased. It could be concluded that the coated paper with high coating solid compared with low coating solid resulted in lower ink usage and better printability on the condition of same print density.

The ink penetration behavior depends on the coating surface structure and surface properties of the coating layer in the papermaking process, which include coating recipes and coating conditions, etc. The objective of this experiment was to investigate the relationship between binder content and ink absorption using laser scanning confocal microscope (LSCM). Fluorescent ink was used to observe and characterize ink penetration and distribution in coated paper by LSCM. The results indicated that higher binder content could result in higher amount ink absorption. With the increasing of binder content, ink penetration depth in coated paper increased. Sample G2 with 20 parts binder produced the most unevenness ink distribution. It could be concluded that the coated paper with 25 parts binder compared with the other samples resulted in higher ink usage and better printing quality.

In present time, recycled paper from xerographic and laser-printed wastepaper plays an important role as alternatives to paper from virgin pulp because of there good pulp quality and high amount of wastepaper each year. This type of paper is classified as Mixed Office Wastepaper (MOW). The xerographic and laser-printed inks are usually called “toner” that mainly consists of styrene-acrylate copolymer. This work investigated paper recycling by washing deinking processes. Experimental parameters were pulp consistencies, amounts and types of surfactant. The resultant pulp of 1.5%consistency and 0.9 wt% of nonionic surfactant, Triton X-100, is the optimum washing deinking process. The resultant pulps have optical and physical properties closed to non-printed paper. Surfactant concentrations were kept below CMC to provide low ink specks, high brigthness and strength on handsheets. The recycled pulp will be use as a raw material for electrical purpose paper.

The purpose of this resarch was investigated the air-oil temperature field distribution under air-oil lubrication and oil lublubrication, meanwhile also study the air-oil lubrication effect under different air velocity inlet the bearing cavities of the high-speed paper machine dryer section. Base on the CFD theory, the temperature field of CARB bearing outer ring and the velocity field of the bearing cavities were simulated by the FLUENT software.Result show that air-oil lubricatin can reach the same cooling effect is contras with oil lubrication in the same heat production by roller; the best air-velocity value of air-oil lubrication system is obtain for the change of temperature and pressure in bearing cavities. It is confirm that the air-oil lubrication is viable in the high-speed paper machine dryer section.

The manufacturing process of particle composite for furniture, made of waste paper and wood particle, was studied and discussed in this paper, and an ornament cabinet and a Chinese style teapoy were assembled in the laboratory with the composite. The results showed the mechanical properties of composite made of waste paper, was low. Wood particle was blended with waste paper and made into composite, and the mechanical properties of the composite could meet the demand of particle board for furniture and ornament under the Chinese national standard. The application of waste paper-based composite was feasible technically.

The main objective of this study was to investigate the effect of drying condition on the binder distribution and characterize the binder migration in the method of numerical and visual analysis by Scanning Electrical Microscopy (SEM), Atomic Force Microscopy (AFM), and Laser Scanning Confocal Microscope (LSCM). In this study, Rhodamine B was used to stain the binder and as the probe to characterize z-directional distribution of the binder using LSCM. The results implied that it was reliable and effective method using LSCM to characterize the z- directional distribution of binder and analyze the influence of dry condition on binder migration. It could be concluded that the dry temperature played an important effect on binder distribution in coated paper and high dry temperature accelerated binder migration to the coating surface, however low drying temperature made binder migrate towards the interior of base paper. Moderate drying is good to binder distribution and coating layer forming.

A proprietary in situ chemical vapor deposition (CVD) process was developed to grow a layer of pyrocarbon on carbon paper preform for proton exchange membrane fuel cells (PEMFC). The carbon paper preform is continuously manufactured by dry method. The characteristics of the carbon paper such as surface morphology, polarized light characteristics, and cross-section morphology were characterized using electron microscope, polarized light microscope, respectively. Fuel cell performance of the carbon paper was evaluated using single cell with hydrogen/air at various relative humidity (RH) conditions. The carbon paper with in situ growth of pyrocarbon showed significant improvement in lowering in-plane electrical resistance as well as fuel cell performance at dry condition. The carbon paper as seen under scanning electron microscope showed excellent surface morphology with pyrocarbon connecting carbon fibers tightly by CVD process.

Nano titanium dioxide particles were synthesized by drolysis of TiCl4 through the phase thransfer and pH of the system is adjusted by Na2CO3 At the same time, the particles were characterized by the Transmission Electronic Microscope(TEM) and X-Ray Diffraction(XRD).As the result, it is shown that the TiCl4 solution was transformed from n-octyl alcohol to deionized water phase and reacted with the deionized water at 55°C, the precursors of nano-TiO2—Ti(OH)4 was dried for 6 hours under vacuum at 70°C,then calcined 3 hours in muffle furnace at 400°C.At last, the TiO2 nanoparticles which is uniform distribution, weak agglomeration was synthesized. In addition, wastewater in paper mill treatment with TiO2 nanoparticles was studied by experiment. It is shown that suspended substance and COD in wastewater were brought dwon largely. The mechenism that wastewater was treated is disscussed.

The effect of flotation parameters such as flotation consistency, temperature, flotation time, air to pulp ratio, and turbulence level (velocity of pulp flow) on old book paper deinking efficiency was studied by using a high-consistency laboratory pulper and a laboratory deinking cell. The optimized flotation conditions were: flotation consistency 1.2%, 50°C, 6min, air to pulp ratio 40%, velocity of pulp flow 5.0m/s. By using the optimized flotation conditions, the deinked pulp brightness could reach 77.01%ISO, 9.69%ISO higher than that of the control, the effective residual ink concentration was 175.26 mg/kg, which less than 437.84mg/kg of the control, deinking efficiency was up to 59.97%. After washing process, pulp brightness could reach 84.27%ISO, the effective residual ink concentration was 93.71 mg/kg, deinking efficiency was up to 78.60%.

Relaxation function can well reflect the microscopic polarization mechanism of dielectric. In order to analyze the influence of moisture and temperature on relaxation function of oil-paper insulation, building a physical model of the oil-paper insulation system containing moisture and obtaining the expression of relaxation function. Setting up a testing device for the oil paper insulation dielectric spectroscopy in the laboratory, the parameter values of relaxation function expression were obtained according to test result by Fourier inverse transformation. The results show that the relaxation function containing three relaxation factors are more suited for the relaxation of oil-paper insulation containing moisture content and microscopic polarization mechanism, moisture and temperature have a significant effect on relaxation function.

In this paper, we initially report a new type of wax printing method for rapid fabrication of microfluidic devices in paper using a commercially available, cheap, minitype (home-use) CO2laser engraving machine. This method combines the two core operations commonly involved in all previous wax printing methods, namely the printing and heating (melting) of wax patterns into one operation of engraving home-made wax slice (put in contact with the surface of paper) by laser. The heat produced by the laser makes the wax being engraved melt and then spread into paper to form complete hydrophobic barriers which are used to define the hydrophilic flow channels or separate test microzones. Under the optimized experimental conditions, a typical device on a 3 cm × 3 cm piece of paper could be fabricated separately within ~320 sec and is ready for use once the engraving process is completed. The fabrication resolution and multiplexed analytical capability of the wax-patterned paper were additionally characterized.

In order to prepare the polyurethane with less reliance on the oil resources, natural, renewable castor oil was used as raw materials to replace the traditional oil type polyols. The castor oil-based waterborne polyurethane was synthesized by the reaction of toluene diisocyanate (TDI), castor oil (C.O.), dimethylol propionic acid (DMPA) and triethyl amine (TEA). The results revealed that the best paper surface strength properties could be obtained under the condition that the mole ratio of TDI to C.O. was 3.0, prepolymerization temperature was 75°C and dosage of hydrophilic chain extender DMPA was 12.1%. In addition, picking speed of paper surface sized by this emulsion increased 2.53 times compared to the unsized paper, from 0.81m/s to 2.86 m/s, Printing ink absorption value and PPS value reduced in a reasonable scope, 60 s Cobb value was below 30 g/m2.

In this paper, Old Corrugated Container (OCC) was used as the raw material for making paper. The layer-by-layer (LBL) assembly process of creating highly structured thin films was adopted to modify the surface of OCC fibres. Poly dimethyldiallylammonium chloride (PDADMAC) and hydroxyethyl cellulose (HEC) have been used to build up polyelectrolyte multilayers on OCC fibres under a certain condition. Zeta potential analyzer was used to monitor the dynamic adsorption of PDADMAC and HEC with different amount on OCC fibers. Strength measurements of the sheets including tensile index and bursting index were also determined, showing a significant improvement in physical strength with the increase of adsorbed layer number. Compared with not being processed sheets, tensile index and bursting index of sheets from treated fibre with polyelectrolyte multilayers were raised by 36.65% and 49.50%, respectively. Furthermore, filtration time analysis of OCC fibre suspension showed that the built up of PDADMAC and HEC on OCC fibres could improve the fiber-fiber joint strength of joints from polymer-treated fibers, which made the filtration time decline from 30 s to 10.6 s. In addition, SEM was introduced to observe the morphology of the PDADMAC/HEC multilayers. The images revealed that the surface of OCC fibres structured a film like plastic, which could be ascribed to the adsorption layer of polyelectrolyte.

Self-supporting film of single-walled carbon nanotubes (SWNTs), also known as SWNT paper, is held together by Van der Waals force without any chemical binders. Prepared by vacuum filtration method, SWNT paper was then decorated wirh polypyrrole (PPy) through pulsed potentio amperometric polymerization. The results indicated that the SWNT paper had a typical network structure, after polymerizing PPy, cauliflower-like structure was observed on the surface of SWNT ropes. The composite thin film has good cyclic voltammetry (CV) property and the specific capacitance wass ca.420Fg-1, which was much larger than that of pure SWNT paper.

In this paper two types of oil-paper samples are thermally aged in two temperatures of 120. The samples are constituted by 25# oil, 45# oil and paper. Some aging indicators are measured during the aging process. Three parameters are measured during the aging process. The insulating ability of paper can be evaluated by water content and CO2/CO value. The model of functional relation for degree of polymerization (DP) with CO2/CO value, water content and service period are established by multiple linear regression analysis.

A newly devised process using micro-electrochemical machining (MECE) is described as a recycling module in the current study. The purpose is the precise removal of In2O3SnO2 thin-film nanostructures from optical PET diaphragm surfaces for digital-paper surface. In the current experiment it was found that a large rotational diameter (Dc) for the cathode with a small gap width between the anode and the PET diaphragm surfaces was found to remove the In2O3SnO2 rapidly. A small edge radius of the cathode, or a short arc length of the anode, reduces the time taken for In2O3SnO2 removal. A high feed rate of the PET and adequate electrical power results in fast machining. Pulsed direct current improves dregs discharge and this is an advantage with a fast feed. A high electrode rotational speed also corresponds to faster removal of the In2O3SnO2 nanostructures. The development of the proposed precision production design is based on both technical and economic considerations.

In the offset process, ink penetration performance has extremely important influence on the quality of printed products. Ink penetration behavior and ink transfer volume on the offset paper surface were researched with the aid of IGT printability tester (AIC2-5) in the conditions of temperature 20±3°C and humidity of 60 ± 5%. Effect of different printing pressure and printing speed on the ink penetration depth was discussed, and at the same time, the depth was measured by GX71 Inverted Metallurgical Microscope. The results showed that, with the increasing of printing pressure, the changes of ink penetration depth and the ink transfer volume on offset paper surface were increased firstly and then decreased. When printing pressure was 400N, the ink penetration depth reached the maximum 71.67μm and the ink transfer volume reached the maximum too. With the enhancing of printing speed, ink penetration depth and ink transfer volume would be decreased gradually. The study also found that ink penetration behavior had certain influence on the ink color forming properties. For the offset paper used in this experiment, when ink penetration depth was 60.0μm~63.0μm, the print had high ink color intensity and color efficiency. When the ink penetration depth was too deep, ink color intensity and color efficiency was significantly reduced, while the color hue error would be increased, the print ink color turned shallow.

Carbon fiber paper was modified by adding carbon nanotubes to make it reach the demand of gas diffusion layer (GDL) by the process of impregnation with phenolic resin solution dispersed with carbon nanotubes, molding, and carbonization. The properties of modified carbon fiber paper, thickness, density, porosity, gas permeability, specific resistance and tensile strength, were characterized. The results indicate that surface treatment is helpful to disperse carbon nanotubes in phenolic resin. Phenolic resin is used to bond the carbon fibers, and carbon nanotube could reduce the specific resistance of the carbon fiber paper. When carbon nanotube content is 5 %, modified carbon fiber paper is prepared with thickness of 0.30 mm, density of 0.43 g/cm3, porosity of 77 %, gas permeability of 2400 mL•mm/(cm2•h•mmAq), specific resistance of 0.020 Ω•cm and tensile strength of 15 MPa, which basically qualifies for the application requirement.

Single factor experiment was used to investigate neutral deinking technology of old magazine paper (OMG) by self-compounded NTM-2 deinking agent. Olympus inverted biological microscope were used to research distribution state of ink particles in the secondary pulp before and after deinking treatment. Scanning electron microscopy (SEM) was used to analyze fiber surface changing during neutral deinking and ink particles dispersing behaviors in the paper. The results showed that NTM-2 deinking agent had a good deinking effect to OMG, optimum operation conditions of neutral deinking was NTM-2 0.5%, deinking temperature 50°C, deinking time 40min, repulper time 25s, pulp consistence 1.0%, and floatation time 6 min. Under these conditions, brightness of the deinked pulp increased 8.4%SBD, and the ink removal efficiency reached by 90%. Olympus inverted biological microscope images showed that there were a large number of ink particles in the un-treated pulp, and these ink particles integrated with fibers tightly. After treated by neutral deinking, most of ink particles were separated from the fiber, dispersed and suspended in the pulp evenly. SEM images indicated that there were little ink particles in the secondary paper, the fiber surface turned more smoother, and the clean degree would nearly corresponding to the effect of alkaline deinking.

Ink is transferred and sets onto the paper surface in the printing process, which affect printing quality and usage of ink. The objective of this experiment was to investigate the influence of ink type on ink absorption and characterize the penetration depth through quantitative analysis by Laser Scanning Confocal Microscope (LSCM). Fluorescent ink was used to observe and characterize ink penetration by LSCM. Three-dimensional images of ink pigment penetration were obtained by reconstructing all XY plane images. It could be concluded Common offset printing ink compared with UV offset printing resulted in deeper ink penetration ,uneven ink distribution and lower print density. Because the composition and drying method of UV offset printing ink and common offset printing ink were significant different, penetration depth and distribution uniformity of these two types of offset printing ink in coated paper were distinct.

Graphene is a remarkable material with high electron mobility, good mechanical strength and almost transparent. In this paper, we review the available methods which are chemical vapour deposition, Hummers and electrochemical exfoliation method for the production of graphene. Among the extensive studies in the application of graphene, supercapacitor has gained much attention nowadays. Therefore, we also briefly review the application of graphene as electrodes for the supercapacitor devices.

In this paper, synthesis and fluorescence performance of graphene oxide have been primarily studied. Fistly, graphene oxide with remarkable fluorescence performance was prepared by modified hummer’s method. Secondly, changing the reaction time, the structure and size of graphene oxide were analyzed using X-ray diffraction (XRD) and Malvern Zeta-Size Analyzer, and the effects of different reaction conditions on the XRD patterns of graphene oxide were discussed. Finally, the fluorescence performance of graphene oxide solution were analyzed using fluorescence spectrometer.

The penetration of ink into the paper affects the final appearance of printing and the amount of ink usage. The main aim of this experiment was to investigate the efficiency of coating speed on surface properties and ink penetration and to characterize the penetration depth through quantitative analysis by laser scanning confocal microscope (LSCM). The results indicated that the surface properties of coated paper could be adjusted and improved by increasing the coating speed. With the increasing of coating speed, ink penetration depth declined and ink penetration uniformity increased. It could be concluded that the coated paper with high coating speed compared with low coating speed resulted in lower ink usage and better printability on the condition of same print density.

Nowadays the traditional dyeing wastewater treatments based on flocculation-biochemical technology become more difficult than before. The study in this paper aim was it to probe how adding rare earths (REs) into iron-carbon micro-electrolysis process to advance dyeing wastewater degradation. Firstly, the principle was discussed. Then the experimental methods were stated and it followed by exploring effect of iron powder size on the dye decolorization rate. Next were design of the micro electrolysis orthogonal experiments and discussion of influences of related factors on waste water treatment. The experimental results show that besides common iron powder particle size and the processing time, the factors that have great influence on dyeing wastewater treatment are Ce4+, pH, La3+ and iron/carbon ratio. The sequence of factors influence on wastewater micro-electrolysis treatment is Ce4+ > pH > La3+ > iron/carbon ratio. When pH is 6, COD removal rate arrives at maximum 89%, however when the pH is in the case of too high or too low, the effect of sewage degradation is not good.

In recent years, with the excellent mechanical properties, good thermal conductivity and electrical conductivity and optical properties, Graphene is widely used in many fields such as chemistry, physics and material science .The preparation of graphene have had a very big progress.This paper reviews the chemical preparation methods of graphene and the application of Graphene / Chitosan composite.Then we point out the outlook of the application of the composite materials graphene with other biological macromolecules which are similar with chitosan.

Calcium sulphate is rich in natural resources and by-product of many industrial processes. However, most calcium sulphate product was only used with low added value or treated as waste, harmful to environment. If the calcium sulphate can be used as papermaking filler, very high added value can be gained and also the environment problem can be solved. In this paper calcium sulphate from by product of industry was characterized by X-ray diffractometer (XRD) and scanning electron micrograph (SEM), and then used as papermaking filler. The influence of calcium sulphate filler on pulp suspension and paper properties was studies. The results showed that the calcium sulphate fillers were composed of three crystal forms, dihydrate, hemihydrate, anhydrite, and it was needle or fiber shape, hollow in the middle; calcium sulphate showed high brightness and high conductivity in water, compared with talc or ground calcium carbonate(GCC) filler. When calcium sulphate filler was used in papermaking process the filler retention was very small because of its high solubility in water. Calcination at high temperature can lower the solubility of calcium sulphate and slightly increase the retention, but the retention was still quite small. The future work should focus on controlling the solubility of calcium sulphate.

With the continuous development of printing technology and printing equipments, the quality of newsprint should be improved to meet with all the real demands. Acrylamide copolymer is used in paper-making as process aid and function aid which can effectively improve paper printing adaptability. Preparation and application of polyacrylamide via aqueous copolymerization was studied as dry strength agent in this paper. The polyacrylamide with middle molecular weight and low viscosity was obtained by reacting acrylamide, cationic monomer [2-(acryloyloxy)ethy] -trimethylammonium chloride and N,N-dimethylaminoethyl methacrylate, anionic monomer itaconic acid, active nonionic monomer N-metholacrylamide and crosslinking monomer 1,3,5-triacryloylhexahydro-s-rine, the copolymer was characterized by FT-IR, charge density and molecular weight distribution. On the basis of internal present situation of pulp, the papermaking system with deinking pulp from office waste paper and white water of 1000-1200us/cm conductivity from paper mill were selected for application research. The results show that when the dosage of acrylamide copolymer is 0.8% to the dry weight of pulp and handsheet basis weight is 60g/m2, acrylamide copolymer can show the superior performance to newsprint and receivable cost for paper mill, fluffing speed, tearing strength and internal bonds are respectively improved by 14%, 20% and 30%.

Aiming at the difficulty of treating dyeing wastewater, the limitation of the traditional electrolysis method, the high cost of active carbon and the environmental pollution of the chicken manure in farms, the paper put forward a new method of using iron combined with biological carbon derived from chicken manure forming internal electrolysis to treat dyeing wastewater. It discussed the effects of mass ratio of iron and biological carbon derived from chicken manure, pH, reaction time, the particle size of iron filings, the aeration rate, circulation velocity and the circling liquid volume on the removal rate of the organic matter in wastewater. The result showed that iron combined with biological carbon derived from chicken manure forming internal electrolysis to treat dyeing wastewater could "using waste to treat waste" and the effect was better. The removal rate of COD was over 85% and the decolorization rate was over 95% when the mass ratio of iron and biological carbon derived from chicken manure was 1:1, the PH was 6, reaction time was was 60min, the particle size of iron filings was 0.9~2.0mm, the aeration rate was 10mL/min, circulation velocity was 50r/min and the circling liquid volume was 2000mL.

Chemical, physical, morphological, and mineralogical analysis of sewage sludge originating from a waste water treatment plant in Patras, Greece, is presented in the paper. The sewage sludge is firstly dried at 70°C, then oven-burned at 700°C for two hours and milled. The thermally treated material is analyzed using XRF and XRD, the particle size distribution is determined by a laser diffraction method. A potential use of sewage sludge in blended cements is investigated on the basis of the measurement of mechanical and basic physical properties of pastes containing the sludge in an amount of up to 60% of the mass of cement. Experimental results show that the thermal treatment of pre-dried sewage sludge and its grinding provides a material that can be successfully applied as a partial replacement of Portland cement. At a production of blended cements for high strength concrete, an up to 20% cement replacement level can be recommended.

In this paper, the process parameters of graphene during fabrication and transfer are investigated. Cu is utilized as the substrate and chemical vapor deposition are used to obtain graphene. The results show that, the surface condition of the Cu substrate tends to be worse than as-received after a relatively higher temperature (1035°C) annealing and growth process, which lead to bad graphene quality. In addition, pre-treatment of Cu substrate by acetic acid is helpful to reduce the nucleation sites. Reflow process before PMMA etching is an effective method to eliminate the wrinkles formed during transfer. High-quality graphene for optoelectronic applications were obtained based on the optimized fabrication and transfer process.

One of the main objectives of this study was to activate the pozzolanic activity of sludge, produced by municipal sewage treatment plants (MSTP), make it become an admixture to replace a part of cement in concrete. Nowadays, a significant quantity of MSTP sludge is obtained in China. That is why this paper examines the possibility of adding this waste product to plain concrete with Portland cement. Preliminary studies are carried out on using MSTP sludge as an admixture by thermal (calcining) and mechanical (grinding) treatment. The pozzolanic activity of the calcined sludge ash (CSA) evaluated by Cement Mortar test. The CSA-blended cement concrete was formed into specimens of cubic concrete with 100 mm×100 mm×100 mm. They are with 30 wt. % cement replaced by CSA, which was prepared by the optimal activation conditions. The Cement Mortar test results revealed that the optimal activation conditions of CSA were as follows: calcined at 800°C for 2.5 hours followed by fast cooling in air and then ground until 60 minutes. Besides, the compressive strengths of concrete specimens with added 30% CSA were 103.6% and 105.3% of those of the ordinary Portland cement concrete specimens at 7 and 28 days, respectively. These results demonstrate the feasibility of recycling MSTP sludge as an admixture in concrete for construction engineering.

In this paper, the magnetic graphene oxide (Fe3O4@GO) has been successfully prepared by decomposition of Iron (III) acetylacetonate in the mixture solution of triethylene glycol and GO. atomic force microscope, TEM, XRD and superconducting quantum interference device were used to characterize the material. The results showed that the magnetic Fe3O4 nanoparticles modified graphene oxide has been obtained, and it has superparamagnetism with magnetization saturation of 16.4emu/g. the Fe3O4@GO has a good sustained-release performance, and vitro cytotoxicity confirmed that its security for Fe3O4@ GO as a potential drug carrier.

Graphene is a fascinating new member of carbon materials with honeycomb and one-atom-thick structure, consisting of 2D hexagonal lattices of sp2 carbon atoms covalently bonded. Graphene has a huge theory specific surface area (over 2600 m2 g1), good thermal conductivity, high values of Youngs modulus and fracture strength, high thermal stability and chemical stability and fast mobility of charge carriers, etc.. In recent years, many researchers found graphene have outstanding adsorption capacity of dyes in aqueous solution due to its high specific surface area. This paper summarized the graphene, graphene oxide and functionalized graphene removing various dyes in wastewater.

In this paper, poly(vinylidene fluoride) nanofiber was prepared by an electrospinning method. Graphene oxide sheets was obtained via filtration from graphene oxide aqueous solution which synthesized by Hummers method. By sonication, a homogeneously dispersed and well distributed poly acylic acid and graphene oxide nanosheets solution were obtained, and this can be used to modify the neat poly (vinylidene fluoride) nanofiber membrane for not only increasing the hydrophilic properties but also improving the mechanical properties. The poly(vinylidene fluoride)/graphene oxide composite membrane was characterized by SEM, FT-IR, pore properties and mechanical properties. The composite membrane showed an appropriate pore size, excellent mechanical property comparing with pure poly(vinylidene fluoride) membrane. The results showed the membrane could be feasibly used as a MF membrane.

Graphene oxide (GO) reduction is a promising way for graphene large scale synthesis. Pre-exfoliated graphite was oxidized and reduced. The material was compared to commercial graphene oxide and its reduced sample. The reduction process of graphene oxide is accomplished using sodium borohydride (NaBH4) with variable-valence metal ion – cobalt – assistance. The reduced graphene oxide (RGO) was characterized by Raman spectroscopy. The particle size and suspension stability were determined. Electrical conductivity measurements of GO and RGO samples have been done in temperature range from-150°C to 85°C. Pre-exfoliation effect was determined.

A reduced graphene oxide/nickel (rGO/Ni) composite has been succesfully synthesized using a combination of Marcano’s method for synthesizing graphene oxide (GO), subsequently followed by a facile microwave assisted reduction method. X-ray diffraction results show the presence of graphene and nickel on the prepared samples. In addition, the Fourier Tansform Infrared Spectroscopy measurement showed that the absorption peaks of O-H, C=O, C-OH, and C-O only appear in the GO sample. A Scanning Electron Microscope photograph shows that the morphology of the rGO samples contain nano-layered forms. A Raman spectroscopy characterization of the prepared rGO samples show a peak of G band’s wave number at 1586.5 cm-1. From the calculation of the G band’s wave number, the average number of graphene layers is 1.15.

A new carbon material called graphene has been attracting an increasing research interest owing to its unique electrical and mechanical properties that is useful for the various device applications. The synthesis of graphene from graphene oxide usually involves harmful chemical reducing agents that are toxic and undesirable to human and the environment. By avoiding the use of toxic and environmentally harmful reductants, we report a green approach for the reduction of graphene oxide by using reducing sugars to synthesis graphene. Graphite oxide was synthesized from graphite powder using modified Hummers method. Graphite oxide then further exfoliated to graphene oxide by using ultrasonic irradiation. Graphene then was obtained by the mild reduction of graphene oxide with reducing sugars (glucose, lactose and maltose). The structural study of the as-prepared graphene is characterized by Raman spectroscopy and fourier infra red spectroscopy. Raman and FTIR spectra indicates the partial removal of oxygen functional groups from the surface of GO. Characterizations indicate that graphene oxide is successfully reduced to graphene by sugar.

We measured the resistivity and conductivity behavior of activated carbon and an activated carbon – graphene oxide (GO – AC) hybrid using two point probe method. As graphene oxide is well known as insulator, the effects of different ratio of activated carbon on conductivity of hybrid GO – AC was investigated.

Green composites of Glucose-reduced graphene oxide (GrGO) and manganese (IV) oxide (MnO2) were prepared in a typical chemical synthesis route assisted with ultrasonic irradiation. Conductivity studies conducted via 2-point probe method shows GrGO/MnO2(4:1) possessed electrical conductivity of 30.29 S cm-1with energy band gap of 8.47×10-1eV. The increase of D/G intensity ratio of GrGO with increase MnO2loading indicates more disorder carbon or defects are introduced from the reaction of carbon with MnO4-.

Today, research on graphene and other two-dimensional sp2-hybridized carbon nanomaterials has tremendously impacted the areas of modern chemistry, physics, and materials science and engineering. The significant attraction of these materials can be attributed to the outstanding electrical, optical, electrochemical, and mechanical properties of graphene-like materials, especially in comparison to other carbon materials. In this manner, graphene oxide as a substrate for graphene-like materials reduction process is getting more and more interesting. Although early routes to these materials were challenging, significant advances in synthetic and processing methods have enabled access to high-quality exfoliated graphene oxide sheets in appreciable quantities. Herein, we introduced a simple and efficient method for the high-conversion preparation of graphene oxide using a simplified hummer’s method from large graphite flakes (an average flake size of 100 μm). One-pot chemical oxidation of graphite was carried out at room temperature for the preparation purpose. It was found that different degree of oxidation of graphite flakes could be realized by stirring graphite in a mixture of sulphuric acid and potassium permanganate under different oxidation durations, resulting in exfoliated graphene oxide sheets with large lateral dimension and area. The simplified Hummer’s method provides a facile approach for the preparation of large-area exfoliated graphene oxide sheets.

This article shows us a way to disperse graphene with PEK-c and a method to make graphene/PEK-c films with great surface conductivity. The characterization of grapheme was analyzed by scanning electron microscope (SEM) as well as chloroform without dispersant was identified to be the suitable system to disperse graphene. Graphene/PEK-c films are fabricated in a large scale using coating method. The conductivity of the films were tested by surface resistance tester as well as the surface resistance of graphene/PEK-c film with 50%wt graphene is about 50Ω/sq. Micro cracks were observed by SEM images that were the main reasons to explain the performance differences between real and theoretical conductivity.

Two key issues in graphene-based p-n junction applications are the manipulation of the type and density of carrier in graphene and the development of a facile fabrication process. Here we reported the formation of graphene films with tunable carrier type by doping of ethoxylated polyethylenimine (PEIE) and Au nanoparticles (NPs). The carrier density of doped graphene can be tuned by altering the concentration of the dopant solutions. The doping effects of PEIE and Au NPs on graphene were monitored by resonant Raman spectroscopy and electrical transport measurements. Graphene p-n junction arrays were assembled by simple soft-lithographic patterning and cross-stacking of n-and p-type doped graphene films, showing a graphene p-n junction behavior with two VCNDP.

Graphene oxide (GO) is extracted from graphite oxide synthesized using modified Hummers method. The extracted GO solution is then drop casted onto a p type silicon substrate and dried in hot air oven. The dried solution is annealed at a temperature of about 200 degree Celsius for about one hour to obtain thermally reduced graphene oxide (RGO). Such thermally synthesized RGO usually have a lot of structural defects which can act as a binding site for hydrogen. The binding efficiency of hydrogen to defect centers can be increased by applying electric field to RGO as it changes the carrier concentration (doping) on the surface. This induces more polarization in the hydrogen molecule resulting in strong binding force, thereby increasing its hydrogen storage efficiency. In our experiment we have demonstrated room temperature electric field doping in RGO films by modulating the channel current by changing the back gate voltage which is a precursor for employing RGO in hydrogen storage applications.KeywordsGraphene oxide, Reduced graphene oxide, Field effect, Hydrogen storage, and Defects

Through improving the traditional causticization process, such as needle-like White Mud and rice-like White Mud are obtained by adding auxiliary agent and controlling the causticizing reaction conditions. Results show that the uniform needle-like White Mud and rice-like White Mud can be better applied to paper filling, especially the needle-like White Mud, which demonstrates higher opacity and higher whiteness than commercial PCC, while has the same influence on strength and other properties with commercial PCC.

The objective of this paper is to investigate the influence of curing time on expansive soil as a construction material when treated with eco-cement stabilizer, as partly substituting the Portland cement. Standard consolidation samples were prepared from treated soils with 10 % cement (5% eco-cement and 5% Portland cement), reported to the dry unit weight of soil, and cured for 1, 7 and 14 days. After this period the soil samples were then socked in water and standard consolidation tests were performed on them. The compressibility characteristics, for the improved soil with 10% cement, Eoed, mv and Cv have shown a significant improvement during the first 7 days. After 7 days curing time the variation of compressibility characteristics is less pronounced.

Nitrogen-doped graphene (N-rGO) was synthesized in the process of preparation of reduced graphene oxide from the expanded graphite through the improved Hummers’ method. The morphology, structure and composition of nitrogen-doped graphene oxide (GO) and N-rGO were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The nitrogen content of N-rGO was approximately 5 at.%. The electrochemical performances of N-rGO as anode materials for lithium-ion batteries were evaluated in coin-type cells versus metallic lithium. Results showed that the obtained N-rGO exhibited a higher reversible specific capacity of 519 mAh g-1 at a current density of 100 mA⋅g-1 and 207.5 mAh⋅g-1 at a current density of 2000 mA⋅g-1. The excellent cycling stability and high-rate capability of N-rGO as anodes of lithium-ion battery were attributed to the large number of surface defects caused by the nitrogen doping, which facilitates the fast transport of Li-ion and electron on the interface of electrolyte/electrode.