Water-Based UV-Curable Polyurethane Based on Wheat Straw Lignin Obtained by Ethanol Extraction

2011 ◽  
Vol 295-297 ◽  
pp. 278-281
Author(s):  
Fu Qiang Chu ◽  
Xiang Jiao Wu
Keyword(s):  
Wheat Straw ◽  
Lignin Content ◽  
Average Particle Size ◽  
Uv Curing ◽  
Synthesis Process ◽  
Average Particle ◽  
Uv Curable ◽  
Ethanol Extraction ◽  
Water Based ◽  
Positive Effect

The aim of this paper is to discuss the application of ethanol-dissolved lignin in preparing high value products. Lignin was extracted from wheat straw by ethanol and used to prepare water-based UV-curable polyurethane. The preparation of water-based UV-curable polyurethane was completed by a three-step reaction. Besides lignin, toluene- 2, 4- diisocyanate (TDI), dimethylolpropionic acid (DMPA), 2-hydroxyethyl acrylate (HEA) and polyether glycol (PPG) were used. The effect of lignin content on the synthesis process was studied. The prepared lignin polyurethane was neutralized with tertiary amine (TEA) and dispersed in water. The properties of the final product, for example, rheological property, average particle size, UV-curing ability and mechanical property, etc. were characterized. Results indicated that the lignin polyurethanes could cure quickly and the presence of lignin with a proper proportion during the synthesis had a positive effect on the tensile strength of cured film.

scholarly journals Green synthesis: Proposed mechanism and factors influencing the synthesis of platinum nanoparticles

2020 ◽  
Vol 9 (1) ◽  
pp. 386-398 ◽  
Author(s):  
Mahmood S. Jameel ◽  
Azlan Abdul Aziz ◽  
Mohammed Ali Dheyab
Keyword(s):  
Green Synthesis ◽  
Reaction Temperature ◽  
Platinum Nanoparticles ◽  
Energy Requirement ◽  
Average Particle Size ◽  
High Energy ◽  
Energy Utilization ◽  
Critical Parameters ◽  
Synthesis Process ◽  
Average Particle

AbstractPlatinum nanoparticles (Pt NPs) have attracted interest in catalysis and biomedical applications due to their unique structural, optical, and catalytic properties. However, the conventional synthesis of Pt NPs using the chemical and physical methods is constrained by the use of harmful and costly chemicals, intricate preparation requirement, and high energy utilization. Hence, this review emphasizes on the green synthesis of Pt NPs using plant extracts as an alternative approach due to its simplicity, convenience, inexpensiveness, easy scalability, low energy requirement, environmental friendliness, and minimum usage of hazardous materials and maximized efficiency of the synthesis process. The underlying complex processes that cover the green synthesis (biosynthesis) of Pt NPs were reviewed. This review affirms the effects of different critical parameters (pH, reaction temperature, reaction time, and biomass dosage) on the size and shape of the synthesized Pt NPs. For instance, the average particle size of Pt NPs was reported to decrease with increasing pH, reaction temperature, and concentration of plant extract.

scholarly journals High-Temperature Synthesis of Metal–Matrix Composites (Ni-Ti)-TiB2

2021 ◽  
Vol 11 (5) ◽  
pp. 2426
Author(s):  
Vladimir Promakhov ◽  
Alexey Matveev ◽  
Nikita Schulz ◽  
Mikhail Grigoriev ◽  
Andrey Olisov ◽  
...  
Keyword(s):  
High Temperature ◽  
Composite Materials ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Average Particle Size ◽  
Synthesis Process ◽  
Average Particle ◽  
Temperature Synthesis ◽  
High Temperature Synthesis

Currently, metal–matrix composite materials are some of the most promising types of materials, and they combine the advantages of a metal matrix and reinforcing particles/fibres. Within the framework of this article, the high-temperature synthesis of metal–matrix composite materials based on the (Ni-Ti)-TiB2 system was studied. The selected approaches make it possible to obtain composite materials of various compositions without contamination and with a high degree of energy efficiency during production processes. Combustion processes in the samples of a 63.5 wt.% NiB + 36.5 wt.% Ti mixture and the phase composition and structure of the synthesis products were researched. It has been established that the synthesis process in the samples proceeds via the spin combustion mechanism. It has been shown that self-propagating high-temperature synthesis (SHS) powder particles have a composite structure and consist of a Ni-Ti matrix and TiB2 reinforcement inclusions that are uniformly distributed inside it. The inclusion size lies in the range between 0.1 and 4 µm, and the average particle size is 0.57 µm. The obtained metal-matrix composite materials can be used in additive manufacturing technologies as ligatures for heat-resistant alloys, as well as for the synthesis of composites using traditional methods of powder metallurgy.

Nanosized Hydroxyapatite Powder Synthesized from Eggshell and Phosphoric Acid

2007 ◽  
Vol 7 (11) ◽  
pp. 4061-4064 ◽  
Author(s):  
Sang-Jin Lee ◽  
Young-Soo Yoon ◽  
Myung-Hyun Lee ◽  
Nam-Sik Oh
Keyword(s):  
Phosphoric Acid ◽  
Heating Temperature ◽  
Average Particle Size ◽  
Stoichiometric Composition ◽  
Synthesis Process ◽  
Average Particle ◽  
Mixing Ratio ◽  
Powder Synthesis ◽  
Chemical Route ◽  
Milling Method

The present research describes synthesis of highly sinterable, nano-sized hydroxyapatite (HAp) powders using a wet chemical route with recycled eggshell and phosphoric acid as calcium and phosphorous sources. The raw eggshell was easily turned to CaO by the calcining process, and phosphoric acid was mixed with the calcined eggshell by the wet, ball-milling method. The crystalline development and microstructures of the synthesized powders and sintered samples were examined by X-ray diffractometry and scanning electron microscopy, respectively. The observed phases on the powder synthesis process were dependent on the mixing ratio (wt%) of the calcined eggshell to phosphoric acid and the heating temperature. The ball-milled, nano-sized HAp powder, which has an average particle size of 70 nm, was fully densified at 1300 °C for 1h. The Ca/P ratio for stoichiometric composition of HAp was controlled by adjustment of the mixing ratio.

Synthesis of Emulsion for Water-Based Pigment Ink Jet

2011 ◽  
Vol 380 ◽  
pp. 81-84
Author(s):  
Li Ming Zhang ◽  
Xiu Lan Xin ◽  
Wei Jiang
Keyword(s):  
Particle Size ◽  
Water Resistance ◽  
Average Particle Size ◽  
Average Particle ◽  
Scanning Calorimetry ◽  
Reactive Surfactant ◽  
Potential Value ◽  
Ink Jet ◽  
Water Based ◽  
Pigment Ink

The water-based pigment ink jet emulsion whose particle size was less than 100nm was synthesized by the polymerization of methyl methacrylate, butyl acrylate and ethylhexyl acrylate, and anionic reactive surfactant and nonionic surfactant were used as the emulsifiers. The effects of particle size and water resistance were studied. The glass transition temperature was tested by differential scanning calorimetry. The average particle size of emulsion was range from 60nm to70nm, zeta potential value was less than -60mv; viscosity was 3.5mps; water absorption was 5.9%.

scholarly journals A Comparative Study of Nanostructures of CuO/Cu2O Fabricated via Potentiostatic and Galvanostatic Anodization

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
S. Mary Margaret ◽  
Albin John P. Paul Winston ◽  
S. Muthupandi ◽  
P. Shobha ◽  
P. Sagayaraj
Keyword(s):  
Thermal Stability ◽  
Comparative Study ◽  
Aqueous Electrolyte ◽  
Average Particle Size ◽  
Xrd Analysis ◽  
Molecular Vibration ◽  
Synthesis Process ◽  
Average Particle ◽  
Good Crystallinity ◽  
Cu Foil

A detailed comparative study on the synthesis process of coral-like CuO/Cu2O nanorods (NRs) and nanopolycrystals (NPCs) fabricated on Cu foil employing aqueous electrolyte via potentiostatic (POT) and galvanostatic (GAL) modes is discussed. The structural, morphological, thermal, compositional, and molecular vibration of the prepared CuO/Cu2O nanostructures was characterized by XRD, HRSEM, TG/DTA, FTIR, and EDX techniques. XRD analysis confirmed the crystalline phase of the formation of monoclinic CuO and cubic Cu2O nanostructures with well-defined morphology. The average particle size was found to be 21.52 nm and 26.59 nm for NRs (POT) and NPCs (GAL), respectively, and this result is corroborated from the HRSEM analysis. POT synthesized nanoparticle depicted a higher thermal stability up to 600°C implying that the potentiostatically grown coral-like NRs exhibit a good crystallinity and well-ordered morphology.

Preparation and Magnetic Properties of Carbon Encapsulated Fe-Cu Alloy Nanoparticles

2010 ◽  
Vol 177 ◽  
pp. 673-676 ◽  
Author(s):  
Jun Xue ◽  
Hou Kui Xiang ◽  
Hong Qiao Ding ◽  
Shu Li Pang ◽  
Xue Hua Wang ◽  
...  
Keyword(s):  
Magnetic Measurement ◽  
Average Particle Size ◽  
Soft Magnetic Property ◽  
Copper Nitrate ◽  
Synthesis Process ◽  
Ferric Nitrate ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Alloy

Carbon encapsulated Fe-Cu alloys nanoparticles were synthesized by using ferric nitrate, copper nitrate as metal sources and using sucrose as carbon source. The synthesis process involved a step of hydrazine hydrate reduction in alcohol solution and a step of annealing carbonization. The as-prepared samples were characterized by X-ray diffraction technique, X-ray energy dispersion spectrograph, trans- mission electron microscopy and Raman spectroscopy. The results showed the sample was core / shell structure, the metalic core was crystalline FeCu4 alloy, the shell was amorphous carbon, and the average particle size was about 51nm. The magnetic measurement by using a vibrating sample magnetometer revealed that the sample has ultra-soft magnetic property with the saturation magnetization Ms of 13.01 emu/g, residual magnetization Mr of 0.37 emu/g and coercive forces Hc of 54.43 Oe at room temperature.

Study on the Combination Mechanism of the Water-Based UV Curable Ink and Paper

2015 ◽  
Vol 731 ◽  
pp. 488-491
Author(s):  
Fu Qiang Chu ◽  
Yu Xin Liu ◽  
Chang Li Xu
Keyword(s):  
Uv Curing ◽  
Curing Process ◽  
Double Bonds ◽  
Negative Effects ◽  
Uv Curable ◽  
Low Viscosity ◽  
Water Based ◽  
Ft Ir ◽  
Epoxy Acrylate Prepolymer

The bonding mechanism between water-based UV curable ink and active groups on paper’s fiber during curing process was studied in this paper. Low viscosity water-based UV-cured resin was synthesized by epoxy resins, epoxy diluent, acrylic acid and maleic anhydride in the presence of catalyst. The viscosity of the synthesis system and synthetic products were significantly reduced when epoxy diluent was added to replace parts of the epoxy resin. Epoxy diluent was very useful in reducing the viscosity of the product, but over-dose would have negative effects on the quality of the cured film. The water-based epoxy acrylate prepolymer was used as the substitution for the ink to investigate the binding mechanism between the active groups of prepolymer and fiber under UV irradiation. The prepolymer and photoinitiator were mixed and the mixture was diluted to an appropriate viscosity by a small amount of water, then printed on the paper by the method of analog printing and curred by UV curing machine. The printed paper was used to extract lignin by enzymatic/mild acidolysis. FT-IR was used to characterize the changes of the active groups in lignin. The results showed that the changes of active groups in lignin were founded in the existence of ultraviolet and photoinitiator, which consistent with the change of double bonds in prepolymer. The free radicals produced by photoinitiator in curing process not only promoted the double bonds to polymerize, but also accelerated the active groups of lignin binding. Experiments show that chemical bonds exist between them.

scholarly journals Freeze-Thaw Characteristics of Water-Based Copper Oxide Nanofluid

2018 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Heat Transfer ◽  
Copper Oxide ◽  
Freezing Point ◽  
Average Particle Size ◽  
Solidification Process ◽  
Heat Transfer Fluid ◽  
Average Particle ◽  
Volumetric Concentration ◽  
Freeze Thaw ◽  
Water Based

This research examined the freeze-thaw characteristics of a water-based copper oxide (CuO) nanofluid for its successful application in cold regions, where freezing of heat transfer fluids can occur. The enhanced thermal conductivity (k) of nanofluid makes it valuable as a heat transfer fluid, but k diminishes as the average particle size (APS) of the dispersed nanoparticles grows. Therefore, experiments were conducted to determine the effect of freezing on the APS of nanofluid suspensions due to agglomeration. Additionally, it was studied, if the freezing point of the nanofluid was elevated or depressed as the volumetric concentration of nanoparticles in the suspension was increased from 1 % to 5%. Another objective of this experimental study was to compare the time required for precooling, freezing and subcooling of different concentrations of nanofluids and the base fluid. The results showed that the APS grew by as much as 51.2% larger due to the phenomenon of freezing, which would reduce the heat transfer performance. The addition of nanoparticles did not affect the freezing point of the nanofluids, tested for two particle volumetric concentrations of 1 and 5 %. It was observed that the precooling time of 5% CuO concentration was the longest. For the complete solidification process, the water and 1% CuO had comparable freezing times, while the 5% nanofluid had the shortest freezing time. The subcooling time was increased with particle volumetric concentration.

scholarly journals An Efficient Microwave-Assisted Synthesis Method of Novel Bi2O3 Nanostructure and Its Application As a High-Performance Nanocatalyst in Preparing Benzylidene Barbituric Acid Derivatives

2021 ◽  
Author(s):  
Mahdieh Yahyazadehfar ◽  
Enayatollah Sheikhhosseini ◽  
Sayed Ali Ahmadi ◽  
Dadkhoda Ghazanfari
Keyword(s):  
Barbituric Acid ◽  
Aqueous Media ◽  
Average Particle Size ◽  
Synthesis Method ◽  
Synthesis Process ◽  
Microwave Assisted Synthesis ◽  
Average Particle ◽  
Short Period ◽  
High Yields ◽  
Barbituric Acid Derivatives

Abstract In this study, controllable and optimal microwave irradiation has been used to synthesize the novel nanostructures of Bi2O3 under environmental conditions. The final products had a thermal stability of 210 °C, an average particle size distribution of 85 nm, and surface area of 783 m2/g. The high thermodynamic stability of Bi2O3 nanostructures were confirmed by TG and DSC analyses. The nanostructure nature of compounds, most importantly, the use of effective, cost effective and rapid synthesis route of microwave have created significant physiochemical properties in the Bi2O3 products. These unexpected properties have made the possibility of potentials application of these products in various fields, especially in nanocatalyst applications. It is well-documented that, as Lewis acid, bismuth nanocatalyst exhibits a great catalytic activity for the green synthesis of some bio-active barbituric acid derivatives using precursors with electron-donating or –withdrawing nature in high yields (80-98%). After incorporating this catalyst into the aqueous media, all the reactions were completed within 2-3 min at room temperature. The main advantages of this method are practical facility, the availability of starting materials, and low costs besides the catalyst reusability. Additionally, the catalyst synthesis process may be carried in the aqueous media during a short period with medium to high yields. The obtained results have opened a new window for development of a novel nanocatalyst with practical application.

YVO4: RE3+(RE = Eu, Sm, Dy, Er) nanophosphors: Facile hydrothermal synthesis, microstructure, and photoluminescence

2009 ◽  
Vol 24 (10) ◽  
pp. 3050-3056 ◽  
Author(s):  
Bing Yan ◽  
Jianhua Wu
Keyword(s):  
Particle Size ◽  
Rare Earth ◽  
Electron Microscope ◽  
Hydrothermal Synthesis ◽  
Average Particle Size ◽  
Hydrothermal Process ◽  
Synthesis Process ◽  
Average Particle ◽  
Sodium Vanadate ◽  
Rare Earth Nitrates

YVO4: 10%RE3+(RE = Eu, Sm, Dy, Er) nanophosphors have been synthesized by a facile modified hydrothermal technology to obtain the high purity. The key procedure for this hydrothermal process is the adding order of precursors, in which excess sodium vanadate should be added in the solution of rare earth nitrates. The microstructure (crystal phase, morphology, particle size) of these phosphors are characterized by x-ray powder diffraction, scanning electron microscope, and transmission electron microscope, which indicates that there are some cube-like crystals with tetragonal zircon structure and the average particle size is approximately 40 nm. The luminescent behaviors for the four rare earth ion-activated YVO4nanophosphors have been studied, and, for YVO4: 10%Eu3+nanophosphors in particular, it is found that a different hydrothermal process influences the phase composition, microstructure, and photoluminescence. This result suggests that the hydrothermal synthesis process (by adding sodium vanadate to the solution of rare earth nitrates) is favorable for YVO4nanophosphor to obtain pure phase, small particle size, long luminescent lifetime, and high luminescence quantum efficiency.

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