Microwave-assisted Ball Milling Research Articles

Synthesis of lubricant additive for castor oil: A green and fast approach

The realization of industrial applications of plant-based lubricants depends on well-dispersed lubricant additives. Herein, microwave-assisted ball milling directly grafted L-phenylalanine (LP) onto graphene oxide. The reaction does not require a pretreatment step and avoids high temperatures and catalyst involvement. The prepared LP-functionalized graphene oxide (LP-GO) exhibited hydrophobicity with a water contact angle of up to 133° and could maintain stable dispersion in castor oil for more than 80 days. 0.2 wt% of LP-GO improved the thermal conductivity of castor oil by 11.1 % and contributed to the enhancement of tribological performance under three different conditions. In particular, wear and friction decreased by 7.31 % and 11.54 % under the medium speed medium load condition, respectively. The friction decreased by 25.27 % in the low-speed high-load condition, and the wear decreased by 18.65 % under the high-speed low-load condition. The characterization of the tribological interface revealed that the lubrication mechanism of LP-GO was attributed to its protective and repairing effects at the friction interface. The surface functionalization approach in this paper is rapid and green. It can be extended to other functionalizing agents and nanomaterials, facilitating further applications of vegetable oils in tribology.

Tannic acid/polyethyleneimine functionalized hexagonal boron nitride: Enhancing tribological properties of epoxy-based composite coatings

The interfacial compatibility issue of boron nitride (BN) nanofillers in epoxy resin (EP) matrix is one of the major challenges plaguing the efficient application of composites. Herein, inspired by phenol-amine green chemistry, microwave-assisted ball milling was used to synthesize tannic acid (TA) and polyethyleneimine (PEI) functionalized boron nitride (TA/PEI@BN). Characterization indicated that TA/PEI grafted on BN via both non-covalent and covalent interactions, which improved the interfacial compatibility and cross-linking properties of TA/PEI@BN within the EP. Meanwhile, the introduction of 0.25 % TA/PEI@BN reduced the average friction coefficient and wear rate of the EP composite coating by 17 % and 50 %, respectively. The characterization of the friction interface showed that TA/PEI@BN could exhibit a "sliding complementary repair" effect during friction. This work presents a novel, green, and scalable method for realizing the surface functionalization of BN, beneficial for the further application of high-performance epoxy matrix composites.

Preparation of Zn/Zr-MOFs by microwave-assisted ball milling and adsorption of lomefloxacin hydrochloride and levofloxacin hydrochloride in wastewater

The Zn/Zr-MOFs were synthesized via microwave-assisted ball milling and subsequently characterized using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The thermal stability of the Zn/Zr-MOFs was evaluated through thermogravimetry (TGA). The results demonstrated the exceptional adsorption properties of the Zn/Zr-MOFs towards Lomefloxacin hydrochloride and Levofloxacin hydrochloride. At a concentration of 30 ppm for Lomefloxacin hydrochloride, the addition of 30 mg of Zn/Zr-MOFs material resulted in an adsorption capacity of 179.2 mg•g−1. Similarly, at a concentration of 40 ppm for Levofloxacin hydrochloride, the addition of 30 mg Zn/Zr-MOFs material led to an adsorption capacity of 187.1 mg•g−1. Kinetic analysis revealed that the experimental data aligned well with a pseudo-second order kinetic model. Overall, these findings highlight the significant potential application of Zn/Zr-MOF materials in wastewater treatment.

Solubility Enhancement of Antidiabetic Drug Pioglitazone by using Polymer Platform Technology

A “drug delivery system” should be able to reduce toxicity and improve therapeutic benefits. The present investigation aimed to provide an approach for the solubility and bioavailability enhancement by a novel polymer platform Drug delivery system. Platform technology contains a polymeric system with a release modulator and can accommodate drugs with common physicochemical /therapeutic properties with minimal changes. Pioglitazone, BCS class II drug results in sub-therapeutic plasma drug levels which can cause failure in therapeutic response. When it comes to make PIO dissolved and soluble, microwave assisted ball milling technique was followed. Chitosan and neusiline US2 were used to prepare solid dispersion forming ternary complexation. Optimization of solid dispersion of ternary complexation, a “32 level full factorial design with Design Expert Software version 12” had been used. Pioglitazone–CH-neusiline systems helped in marked development of solubility of initial medicinal water, drug dissolution and drug stability. According to the “FTIR, DSC, and XRPD studies, PIO-CH-NS complexes could be prepared by microwave-assisted milling technology has formed stable crystalline in a ternary complex system. A novel polymer platform technique increases bioavailability, enhancing the therapeutic effect while reducing the toxicity of drug molecules with improving patient compliance.

A green modification technology of carbon nanotubes toward enhancing the tribological properties of aqueous-based lubricants

Herein, a green and efficient method is proposed for preparing highly stable aqueous dispersions to realize the potential applications of carbon nanotubes in water. Functionalized carbon nanotubes (CNTs@CMC-Na) were rapidly prepared using a microwave-assisted ball milling apparatus. Sodium carboxymethyl cellulose was grafted on carbon nanotubes through various actions and CNTs@CMC-Na exhibited excellent dispersibility, which increased the thermal conductivity of pure water by 97.6 %. The tribological tests and surface analysis indicate that CNTs@CMC-Na have protective, mending, and cooling effects at the friction interface. The CNTs@CMC-Na aqueous dispersion (0.2 wt%) reduced the average friction coefficient, average wear width, and temperature of the friction interface by 50.13 %, 58.3 %, and 38.9 %, respectively. This study provides a new idea for the preparation of lubricant additives.

Artificial Intelligence-Based Rapid Design of Grease with Chemically Functionalized Graphene and Carbon Nanotubes as Lubrication Additives

Rapid chemical functionalization of additives and efficient determination of their optimum concentrations are important for designing high-performance lubricants, especially under multi-additive conditions. Herein, chemically functionalized graphene (FGR) and carbon nanotubes (FCNTs) were rapidly prepared by microwave-assisted ball milling and subsequently introduced into grease as additives. The tribological properties of the additives in grease at different concentrations and ratios were measured using a four-ball test. A reliable artificial neural network (ANN) model was established according to a few test results. Subsequently, the optimal concentration of multiple additives in the grease was predicted using a genetic algorithm and experimentally validated. The results indicated that the introduction of FGR (0.14 wt %) and FCNT (0.16 wt %) improved the antifriction and anti-wear performance of the base grease by 25.66 and 29.34%, respectively. The results of the ANN model analysis and friction interface characterization indicate that such performance is principally attributed to the synergistic lubrication of the FGR and FCNT.

Preparation of metal–organic frameworks by microwave-assisted ball milling for the removal of CR from wastewater

Abstract Metal–organic frameworks (Sm-MOFs) were prepared using a microwave-assisted ball milling method with a water solution. The structure was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and SEM, and the thermal stability of the Sm-MOFs was tested by Thermogravimetry (TGA). The results showed that the Sm-MOF material exhibited a favorable effect on removing the organic dye Congo red (CR). When the concentration of CR was 80 ppm, adding 50 mg of Sm-MOF material achieved an adsorption capacity of 396.8 mg·g−1. The experimental data were analyzed theoretically through dynamics, and the experimental results were consistent with the second dynamics model, with correlation coefficients (R 2) all above 0.99. Comprehensive data analysis revealed that the Sm-MOF materials had great potential for future application in wastewater treatment.

Preparation of Zn-MOFs by microwave-assisted ball milling for removal of tetracycline hydrochloride and Congo red from wastewater

Abstract In this study, we prepared Zn-MOFs as an ordinary, low-cost, and efficiency method taking advantage of zinc(ii) acetate monohydrate and 1,3,5-benzenetricarboxylic acid in microwave-assisted ball milling. The Zn-MOFs were measured via scanning electron microscopy, infrared spectrometry, X-ray diffraction, and thermogravimetry. We explored its use as a photocatalyst for the degradation of tetracycline hydrochloride and Congo red from aqueous solutions. The results demonstrate that the kinetic model was appropriate for the removal of organic pollutants. In general, it is feasible, inexpensive, and effective to use metal organic framework (MOF) to treat waste liquid. Therefore, our findings indicate that Zn-MOFs have broad application vista in wastewater purification.

Adsorptive and Photocatalytic Dye Removal from Wastewater Using Metal-Organic Frameworks

Trimesic acid in conjunction with microwave-assisted ball milling was used to produce Fe-based metal-organic frameworks (Fe-MOFs). Fe-MOFs were then used to eliminate organic dyes from aqueous solutions. Our results indicated Fe-MOFs eliminated nearly all Methylene Blue (MB) and Methyl Orange (MO). Within 120 min of Xe or natural light exposure, Fe-MOFs were able to remove 93.11% and 91.6%, respectively, of 10 mg/L MB in a 200 mL solution. Within 300 min of Xe or natural light exposure, Fe MOFs were able to remove 96.34% and 52.32%, respectively, of 5 mg/L MO from a 200 mL solution. Collectively, these results show that both dyes are suitable for use in the second kinetic model.

Dispersion stability and tribological properties of additives introduced by ultrasonic and microwave assisted ball milling in oil.

Graphene and MoS2 were modified by organic molecules to obtain modified reduced graphene oxide (MRGO) and modified molybdenum disulfide (MMD) powders. MRGO and MMD were uniformly dispersed in base oil (PAO6) by ultrasonic and microwave assisted ball milling (UMBM). This study tested the dispersion stability and tribological properties of additives in the oil, and analyzed the elements of the friction surface. Besides, the mechanism of anti-friction and anti-wear was discussed. The results show that the UMBM method is an effective way to introduce additives in lubricating oil. Compared with direct addition, it can effectively improve the dispersion stability of additives in the oil, so that additives can be better deposited and adsorbed on the friction surface in the friction process, and improve the tribological properties of lubricating oil.

Water-dispersible graphene–wrapped MnO2 nanospheres and their applications in coin cell supercapacitors

A highly stable and more water-dispersible graphene (WDG) was synthesized using microwave-assisted ball milling technique. The WDG-wrapped MnO2 nanocomposites were prepared for two mass ratios of nanospheres and graphene sheets using reflux method. Comprehensive characterization of the prepared WDG-Mn1 and WDG-Mn2 hybrid nanocomposites was carried out to explore the electrochemical capacitance behaviors. The WDG-Mn1 and WDG-Mn2 electrodes showed capacitance performance of 130 F g−1 at 0.5 A g−1 and 178 F g−1 at 0.5 A g−1, respectively. The WDG-Mn2 electrode revealed enhanced capacitance performance, that is, 84% of its initial capacitance was retained even after repeating the cyclic voltammetry test for 3000 cycles. This study reveals the enhanced capacity performance in WDG-Mn2 nanocomposite hybrid materials for supercapacitors.

Preparation of Fe(III)-MOFs by microwave-assisted ball for efficiently removing organic dyes in aqueous solutions under natural light

Fe-based metal-organic frameworks(Fe(III)-MOFs)were synthesized by Fe2(SO4)3 and trimesic acid using microwave-assisted ball milling method. The structure of the Fe(III)-MOFs was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR). The thermostability of the MOFs was analyzed by thermogravimetric analysis (TGA). Fe(III)-MOFs were added in aqueous solutions to remove organic dyes. The removal efficiencies of Orange II, CR and MB reached 95.9%, 98.7%, 95.7% respectively at 10℃ and reached 97.7%, 99.7%, 97.5% respectively at 35℃ in 300 min.

Effect of structures on the adsorption performance of Cobalt Metal Organic Framework obtained by microwave-assisted ball milling

The Co-MOFs were efficiently and low-costly synthesized by microwave-assisted ball milling without organic solvents and the adsorption of Congo Red (CR) was studied in view of adsorption kinetic and isotherm. It's find that the formation of two different structures due to the change in the molar ratio of the raw material, which contribute to a larger difference of the adsorption. The maximum adsorption capacity of the Co-MOFs toward CR reached 4885.20 mg/g. Open active metal sites and π-π stacking interactions are thought to play an important role in the adsorption of CR onto the Co-MOFs.

Degradation of p-Nitrophenol by Nanoscale Zero-Valent Iron Produced by Microwave-Assisted Ball Milling

AbstractThe applicability of microwave-assisted ball milling for the treatment of p-nitrophenol (PNP) was investigated in this study. The degradation process of PNP was studied by using UV-vis (ult...

The decolorization and mineralization of orange II by microwave-assisted ball milling.

This study proposed an integrated technique of reduction coupled with an oxidation process in order to acquire simultaneously both decolorization and mineralization of orange II under the condition of microwave-assisted milling. Experimental variables of initial dye concentration, iron dosage, microwave power, solution pH and initial H2O2 concentration were systematically studied. Under the optimal operational parameters (100 mg/L aqueous solution of pH 3 containing 400 mg/L H2O2 while controlling microwave power at 400 W), the results showed that the decolorization efficiency is up to 91% after reaction for 2 min and the total organic carbon removal efficiencies were 72.7% and 80.5% at a reaction time of 10 min and 60 min, respectively. It indicated that the decolorization and mineralization of orange II were largely enhanced by the reduction of zero-valent iron in the ball milling process and the oxidation of hydroxyl radicals generated by hydrogen peroxide. It suggested that microwave-assisted ball milling technology has potential application for degradation of azo dye in wastewater.

Synthesis and characterization of metal–organic frameworks fabricated by microwave-assisted ball milling for adsorptive removal of Congo red from aqueous solutions

In this study, four metal–organic frameworks (MOFs) were prepared using a simple, low-cost, and high-efficiency technique utilizing simple carboxylic acids and metal salts by microwave-assisted ball milling.

Preparation of Fe-MOFs by microwave-assisted ball milling for reducing Cr(vi) in wastewater.

Fe-Based metal-organic frameworks (Fe-MOFs) were prepared with trimesic acid and FeSO4·7H2O via a microwave-assisted ball milling approach. The structure and thermal stability of the as-prepared Fe-MOFs were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). When used to degrade 20 mg L-1 hexavalent chromium in aqueous solution, the Fe-MOFs were found to completely reduce a 100 mL solution within 120 min under natural light and a 400 mL solution within 90 min under Xe lamp irradiation. Under natural sunlight, 98% of the Cr(vi) was removed from a 40 mL solution after 40 min.

A study of the mechanism of microwave-assisted ball milling preparing ZnFe2O4

In this paper, well dispersed ZnFe2O4 nano-particles with high magnetization saturation of 82.23emu/g were first synthesized by microwave assisted ball milling and then the influences of pre-treatments and microwave powers to the progress were studied. It was found that under the both function of crack effect induced by ball milling and rotary motion induced by microwave the synthesized ferrtie nano-particles were well dispersed that is much different from the powders synthesized by normal high energy ball milling. The pre-treatment of ball milling can only enhance the reaction rate in the first several hours but the pre-irradiation of microwave can enhance the hole reaction rate. Further more, it was also been found that with increasing the microwave power, the more raw materials will converted into zinc ferrite in the first 5h. 5h latter the microwave power of 720W is high enough for the coupling effect of microwave and ball milling with stirrer rotation speed of 256rpm.

Preparation and photocatalytic properties of zinc oxide nanoparticles by microwave-assisted ball milling

Hexagonal wurtzite ZnO nanoparticles with the average size of about 15nm were successfully prepared by microwave-assisted ball milling. The as-prepared ZnO nanocrystals were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–visible spectrophotometer, fluorescence measurements, and electroconductivity detections. The results showed that single-phase hexagonal wurtzite ZnO nanoparticles were obtained after 20h by microwave-assisted ball milling. The UV spectrophotometer analysis confirms that photocatalytic activity of as-synthesized ZnO nanoparticles under ultraviolet light is demonstrated via methyl orange degradations of 95%. In addition, the measurement results of the relative content of OH radicals in the aqueous solution and the relative conductivity of the solutions verify that the coupling of microwave and ball milling significantly enhanced the chemical reaction.

Preparation and microwave absorption properties of Ni–Co nanoferrites

NixCo1−xFe2O4 (x=0.2, 0.5, 0.8) particles were prepared by a self-designed method, i.e., microwave assisted ball milling. A series of characterizations were carried out on the prepared powders, including X-ray Diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and vector network analyzer (VNA). XRD and TEM results indicated that the particles are well-crystallized and the average size is about 15nm. According to VSM results, the Ms values are 76emu/gm, 61emu/gm and 46emu/gm respectively, which obviously presented higher saturation magnetization values compared with other existing methods. Complex permittivity and permeability of Ni–Co ferrites were explored by VNA in the frequency of 2–18GHz, and the reflection loss (RL) was also calculated. The results illustrated that the minimum reflection loss values of the three ferrites all emerged in the range of 9–12GHz, and the Ni0.8Co0.2Fe2O4 with a thickness of 2.5mm could achieve −36.2dB at 11.52GHz, which indicated that the Ni–Co ferrite nanoparticles possessed great potential in microwave absorption applications.