Wet Grinding Method Research Articles

Research on Mechanical Properties of Silica Fume Cementitious Materials Excited by Wet Grinding Methods

Silica fume (SF) has been widely used in engineering; however, its densification during transportation reduces its original pozzolanic activity. This paper investigates the effects of wet grinding and chemical activation on the mechanical properties and hydration products of silica fume in cement-based materials, revealing the mechanism by which wet grinding improves these properties. The results indicate that wet grinding effectively reduces the particle size of silica fume. Under optimal excitation conditions (250 r/min, 20 min), the median particle size is reduced to 12.1 μm, 2.27 times smaller than before excitation. The 28-day compressive strength of the silica fume cement paste reaches 60.8 MPa, 23.7% higher than that of the reference group. This approach effectively mitigates nano-agglomeration, enhances the pozzolanic activity of silica fume, and promotes AFt and C-S-H gel formation. The findings demonstrate that wet grinding activation can further enhance the utilization rate of silica fume.

Phytochemical properties and antioxidative activities of ginseng superfine powders prepared by wet grinding method with high-pressure homogenization

Ginseng is widely used in agricultural products, dietary health supplements, and pharmaceutical preparations, which has significant market potential. It is of great significance to develop a more efficient and environmentally friendly production process of ginseng powder. However, ginseng is difficult to be milled to an ideal state by dry grinding method because of its higher fiber content. In the meantime, ginseng has high viscosity when suspended in a liquid, which can pose challenges during wet grinding processes. In order to develop a production process for ginseng powder with excellent physicochemical properties, three kinds of powders were obtained by both dry grinding method (ball mill) and wet grinding method (colloid mill&high-pressure homogenizer) in this study. The powder properties, structural properties, saponin contents,and antioxidant activity of different ginseng powders were also investigated. The results showed that wet grinding technology using a high-pressure homogenization process could significantly improve the powder properties，including the particle size, specific surface area, span value, water holding capacity, and appearance. Moreover, both the saponin contents and the antioxidant activity of the powder had been significantly enhanced. The findings indicated that high-pressure homogenization process was a promising technique for producing plant powders rich in bioactive compounds, which could enhance their bioactivity. The method was argued to be a significant alternative technology for production of ginseng ultrafine powders. Furthermore, it offered theoretical and technical support for the application of the high-pressure homogenization process in the preparation of ultrafine powders with reduced particle sizes from high-fiber plants.

An environmentally friendly, rainfall-resistant suspension prepared based on halloysite nanotubes for the delivery of hydrophobic pesticides

The application of nanomaterials in pesticide system shows many advantages such as enhanced dispersion stability, high foliar affinity, improved insecticidal effect, and reduced environmental risks. In the study, a simple wet grinding method was used to decrease the particles size of the pesticides chlorobenzuron and indoxacarb (CI) in presence of halloysite nanotubes (HNTs). The irregularly shaped suspension pesticide system (CI@HNTs) in size of ∼ 2 μ m is obtained via HNTs and xanthan gum (XG) encapsulation of the hydrophobic pesticides. Attributed to the small size and interfacial interactions of HNTs, CI@HNTs have excellent stability, dispersion and slow release behavior. CI@HNTs exhibit enhanced foliar wettability, spreading and topological effect on plant leaves compare to commercial suspension concentrate (SC) product and CI (without HNTs), which results in high resistance to rainfall washout. In the crop model treated by fall armyworm, the mortality rate is 53.3 % in CI group, while the mortality is 75.0 % in CI@HNTs-8 which is 1.41 times that of CI. In addition, the safety of CI@HNTs is systematically evaluated, and the results show that the toxicity of CI@HNTs to the wheat and the aquatic organism zebrafish is lower than that of the SC. This study develops an economical, efficient and environmentally friendly pesticide system based on natural clay nanotubes, which shows promising applications in sustainable agricultural production.

Surface roughness and fracture cracks of Al2O3/TiO2 composite coating by wet chemical mechanical grinding with structured abrasives pad

In the fields of wind power, and other industries, the Al2O3/TiO2 coating is prepared and ground on the bearing ring, in order to obtain the insulation resisting the electrical erosion for the motors at high voltage. A novel wet chemical mechanical grinding (WCMG) method is proposed to finish this hard-brittle composite material, utilizing the structured diamond abrasives pad and the NaOH solution. The softened workpiece's surface under the chemical reaction was demonstrated by means of Raman spectrum, indentation and scratching tests. The analytical model of surface roughness and fracture cracks is established based on the synthesis of geometry and kinematics, contact mechanics, material removal and indentation fracture mechanics. The surface roughness of coating was reduced from initial Sa 3.293 μm down to final Sa 0.049 μm in the WCMG process with grain size 3 μm and pH 12.01, mostly attributed to the ductile removal of chemically softened coating surface.

Selective pharmaceutical sensitization design based on amino acid metabolism: 5-fluorouracil-sarcosine cocrystal prepared by wet powder grinding method

Pharmaceutical cocrystal is an emerging strategy not only to improve physicochemical properties, but also to generate synergistic effects. In this work, a novel cocrystal composed by 5-fluorouracil (5-FU) and sarcosine (SAR) was successfully assembled by wet powder grinding method. The cocrystal was characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and Raman spectra. The differences of 1H NMR spectroscopy between 5-FU/SAR physical mixture (PM) and cocrystal hinted the existence of supramolecular interactions between 5-FU and SAR in solid and solution. Bioavailability of cocrystal was increased than 5-FU. Most importantly, the weak interactions between 5-FU and SAR in cocrystal solution induced the superior cellar inhibition activity on 4T1 and BEL-7402 cells compared than 5-FU and PM. Cocrystal can interfere with the stability of methionine cycle and tetrahydrofolate (FH4) level through the SAR-Gly-Met pathway, enhance the inhibition of thymidylate synthase (TS) compared to 5-FU, thereby interfering with cell cycle and inducing cell apoptosis. The results provided the novel strategy to develop the cocrystal drugs using bioactive amino acids as precursors to enhance the efficacy.

Fabrication of Functional Coating Layer for Emerging Transparent Electrodes using Antimony Tin Oxide Nano-colloid

This study fabricated a functional coating layer for transparent electrodes using antimony tin oxide nanopowder. The wet grinding method was employed to create a stable dispersion solution of antimony tin oxide nanopowder with aminopropyl tri-methoxysilane and acetyl acetone as primary dispersing agents. Various concentrations of these dispersing agents were used to determine optimal conditions, followed by a gel reaction to form a stable solution. The primary objective was to provide a viable alternative to indium-based transparent electrodes, specifically indium tin oxide, by incorporating antimony oxide. This approach not only addresses limitations associated with indium, but also enhances mechanical properties. The methodology involves the utilization of antimony tin oxide nanopowder and various solvents including ethanol and aforementioned dispersing agents to create a stable antimony tin oxide sol through wet grinding. Effects of dispersant concentration and milling time on the secondary particle size of the antimony tin oxide sol were thoroughly evaluated. Furthermore, this study examined sheet resistance of resulting coating layers by conducting a comparative analysis between antimony tin oxide and indium tin oxide under similar conditions. Findings of this study meticulously detailed in subsequent sections of the manuscript provide valuable insights into optimizing the entire process, encompassing synthesis, coating, heat treatment, and the production of high-quality transparent conductive coatings. These techniques and outcomes can significantly contribute to the development of more sustainable and cost-effective alternatives to traditional indium-based transparent electrodes.

Preparation of a Novel Adhesive from Highly Fibrillated Kozo Fibre for Paper Conservation

Abstract In this study, Kozo fibres were fibrillated using the stone wet milling method and the wet atomisation method both deriving from nanocellulose production processes. Kozo fibres with a high degree of external fibrillation were obtained by using the stone mill wet grinding method. Although fibres exhibited the same structure as untreated Kozo fibres, their bonding properties improved. Applying the wet atomisation method, fibrillated Kozo fibres with different degrees of fibrillation were obtained depending on the number of treatments. Fibrillated Kozo fibres can be used in conservation as an adhesive for lining and other stabilisation treatments and may in certain cases replace starch paste, which is susceptible to microbiological damage. Only Kozo fibres and water were used in both mechanical fibrillation methods; therefore, the resulting material can be considered a safe alternative to more traditional adhesives.

Photocatalytic persulfate activation by highly dispersed nano-TiO2 supported by silica for efficient carbamazepine degradation

A silica-loaded nano-TiO2 composite (A-SiO2/TiO2) was prepared by wet-grinding method, using industrial silica (A-SiO2) as the carrier. A-SiO2/TiO2 was used for photocatalytic activation of peroxymonosulfate (PMS) to degrade carbamazepine (CBZ). The A-SiO2/TiO2 containing 20 wt% nano-TiO2 resulted in the CBZ degradation efficiency of 94.83 % after 90 min simulated sunlight irradiation with the presence of PMS. The main reactive species during CBZ degradation in the system of photocatalytic PMS activation by A-SiO2/TiO2 were O2•−, •OH and SO4•−. Compared to nano-TiO2, A-SiO2/TiO2 exhibits enhanced dispersion, increased surface active sites and improved photo-generated carrier separation efficiency, which contributed to enhanced degradation performance.

Preparation and Characterization of Usnic Acid Nanocrystals with the Wet Grinding Method Using a Planetary Ball Mill

Preparation and Characterization of Usnic Acid Nanocrystals with the Wet Grinding Method Using a Planetary Ball Mill

Chiral 5-fluorouracil-arginine cocrystals screened by wet powder grinding method: Leading to synergistic anti-tumor and alleviate cardiotoxicity

Arginine (ARG) is a precursor for producing NO, which can relax vascular smooth muscle. We herein report cocrystals screened by powder grinding using chiral ARG to improve the bioavailability of 5-fluorouracil (5-FU) and alleviate 5-FU induced cardiotoxicity. The results of powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) inferred the formation of new solid phases. Hydrogen bonding interactions between C=O group and N-H were supported by Fourier transform infrared (FTIR) spectroscopy. The spectra intensity of circular dichroism (CD) of cocrystals were higher than that of ARG after combined with non-optically active 5-FU. The bioavailability and cytotoxicity of 5-FU were enhanced by cocrystallization. Notably, L-cocrystal prepared using biologically active L-ARG released lower dose NO in human umbilical vein endothelial cells (HUVEC) cells than that of D-cocrystal. D-cocrystal performed higher NO release ability by non-enzymatic pathway, indicating a greater potential to alleviate cardiotoxicity. 5-FU-induced cardiotoxicity in rats was effectively alleviated, proved by the least increased LDH, cTnI and CK-MB level induced by D-cocrystal.

Preparation of a UV anti-aging and superhydrophobic self-cleaning coating by loading nano-rutile on sericite and being modified with HDTMS

To enhance the anti-aging property of a superhydrophobic self-cleaning coating, rutile nano-TiO2 was loaded onto the surface of sericite via wet grinding method to prepare sericite-rutile composite particles. Then, the composite was modified with hexadecyltrimethoxysilane (HDTMS) and sprayed onto the substrates surfaces to prepare sericite-rutile/HDTMS composite coatings with both UV shielding and superhydrophobic self-cleaning properties. The structure, properties, and mechanism of the coating were studied. The research showed that the micro-nanoscale hierarchical structure has been constructed by compositing sericite and rutile, which were the structure foundation of superhydrophobic coatings. The sericite-rutile composite was modified with HDTMS and sprayed onto the substrates forming a superhydrophobic self-cleaning coating. Water contact angles (WCAs) and slide angles (SAs) of the coating were 155.3° and 1.3°, respectively. The sericite-rutile/HDTMS coating exhibited good UV shielding and anti-aging properties. Its UV shielding rate was 93.53%, which was equivalent to that of pure rutile (94.27%). After UV irradiation for 80 h, the surface maintained superhydrophobicity, and the chromaticity of the coating surface did not change. The superhydrophobicity and low adhesion to water of the sericite-rutile/HDTMS coating are due to the micro-nano hierarchical structure of the sericite-rutile composite and the low surface energy of HDTMS. The UV shielding effect of the coating is mainly due to the strong absorption of UV light by the sericite-rutile composite. This work provides a simple and environmentally friendly method for constructing a coating with UV shielding and superhydrophobic self-cleaning properties.

Preparation and Characterization of Nano-waste glass powder

This experimental study investigates top-down grinding to turn used waste glass into nano-glass powder. The study explores a new instrument locally manufactured to synthesize nano-glass powder. The high-energy ball mill was manufactured based on design, material, assembly, testing, optimization, and quality control. Two milling environments were examined: wet with water as a surfactant liquid and dry with varying grinding times. In addition, this study compared the output of nano glass created from mechanical and chemical grinding processes. Blaine's method for surface area measurement results of nanoscale powder samples produced by the wet grinding method showed a steady increase commensurate with the grinding duration, as the 12-h grinding specimen was the highest in surface area. In contrast, dry grinding samples showed anomalies in some instances due to the agglomerate phenomenon, such as 8- and 10-h grinding samples. Moreover, FE-SEM showed that the 12-h grinding specimen has the smallest particle size. But the AFM illustrated accurately with the 2D measurement that these particles have cortical shapes, which may describe the secret beyond the high surface area. X-ray diffraction (XRD) and AFM tests showed that in the case of nanoscale glass particles, regardless of their morphology status, the shape of the particle itself is the deciding factor in giving the Nano powder the highest particle surface area. The specimen milled with 4 h of dry grinding is best suited for civil engineering research applications, while other applications that need a small amount of nano glass are recommended to use chemical methods despite their dangerous processes.

Utilization of ultra-fine copper slag to prepare eco-friendly ultrahigh performance concrete by replacing silica fume

The present study aims to determine the feasibility of using ultra-fine copper slag (WCS) to prepare eco-friendly ultrahigh performance concrete (UHPC) by replacing silica fume (SF). The variation of hydration progress, mechanical property and microstructure development of UHPC as function of WCS was evaluated. Experimental results indicated that WCS could be prepared and the fayalite could be decomposed by using wet-grinding method. The UHPC pastes behaved like Herschel-Bulkley (H-B) fluids and the shear-thickening behavior was more pronounced as the increase of WCS dosage, implying that WCS has negative impact on workability of UHPC to some extent. WCS had no negative impact on the hydration of UHPC pastes at the early stage and exhibited good pozzolanic activity at the later stage, so as to generate more hydration products to refine the pore structure, thus making UHPC with WCS to obtain better mechanical strength than that without WCS. Replacing SF in UHPC by WCS has significant economic benefits, while the negative impact on CO2 emissions can be negligible.

Performance of cement-based materials incorporating ultra-fine copper slag

The application of copper slag (CS) as a supplementary cementitious material in concrete is unsatisfactory due to the fact that CS is mainly composed of fayalite. The dissolution kinetics of fayalite determines the pozzolanic activity of CS. How to improve the dissolution of fayalite is a challenge for CS resource utilization. To address this issue, ultra-fine CS with different fineness was fabricated by wet-grinding method for the first time in this work and the performance of cement-based materials incorporating ultra-fine CS was assessed. Results revealed that an increase in CS fineness significantly promoted the decomposition of fayalite to improve the mechanical strength of mortars. The 7 d and 28 d strength activity index of ultra-fine CS can reach 106% and 102%, respectively, which has seldom been reported in the literature. Although ultra-fine CS can significantly accelerate the hydration process at the very beginning of reaction to form more hydrates, the early-age pozzolanic activity was still not ideal. The prepared ultra-fine CS exhibited good later-age pozzolanic activity, which can consume more portlandite and generate more hydrates, resulting in a denser microstructure. These results indicated that ultra-fine CS can be used as a high-quality alternative cementitious material to improve the greenness of cement and concrete products.

Effectiveness of Dry Grinding and Wet Grinding Methods on Solution and Dissolution Rate of Nimodipine-HPMC Nanoparticles

Nimodipine is a dihydropyridine calcium channel blocker that shares the general properties of nifedipine, but acts mainly on cerebral blood vessels. Nimodipine belongs to the Class II Biopharmaceutical Classification System (BCS) drug group, which has low solubility and high permeability. The purpose of this study was to look at the differences in the yield of nanoparticles between the dry grinding and wet grinding methods on the physicochemical properties, solubility, and dissolution rate of nimodipine nanoparticles. The nanoparticles were prepared a nimodipine: HPMC ratio of 1:0.6 using two different methods. Sample characterization was carried out using Particle Size Analyzer (PSA), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), and Fourier Transform Infrared (FT-IR). The Solubility test was carried out in CO2-free distilled water and the dissolution rate was carried out in phosphate buffer pH 7.2. The solubility of pure nimodipine in CO2-free distilled water was 0.339 µg/mL, the physical mixture was 1.948 µg/mL, the dry grinding nanoparticles were 3.367 µg/mL, and the wet grinding nanoparticles were 19.952 µg/mL. The dissolution test results obtained with the percentage of pure nimodipine dissolution at 60th minutes was 33.947%, the physical mixture was 39.482%, the dry grinding nanoparticles were 49.798%, and the wet grinding nanoparticles were 56.484%. Based on the results of the study, it can be said that the nimodipine-HPMC nanoparticles significantly increased the solubility and dissolution rate of nimodipine.

Enhanced Solubility and Dissolution of Drug-drug Cocrystals of Lopinavir-Ritonavir

Abstract: Introduction: Drug-drug cocrystals of Lopinavir and Ritonavir were designed and characterized. In view of literature, Ritonavir increases the oral bioavailability of Lopinavir in low dosage. Aim: The present research aimed to improve the solubility, dissolution, and oral bioavailability of Lopinavir through a cocrystallization approach using Ritonavir as a coformer. Materials and Methods: Cocrystallization was carried out using wet grinding and solvent evaporation methods. Prepared Cocrystals were examined and evaluated using characterization methods such as DSC, PXRD, FTIR, Polarized light microscopy, % Drug content, FE-SEM, Micromeritics properties, Solubility, Dissolution, and Stability studies as per ICH guidelines. Results: Developed cocrystals were showed superior solubility and dissolution as compared to pure drug. After 48 hr, aqueous solubility of Lopinavir and Ritonavir co-amorphous formulation (LRCWG) was increased 3.7-fold in the wet grinding method, while Lopinavir and Ritonavir Cocrystals Prepared by Solvent Evaporation Method (LRCSE) indicated 5.9-fold increase compared to pure drug. The co-amorphous formulation was developed using wet grinding showed 86% drug release at 60 min, and cocrystals synthesized through solvent evaporation method showed 94% of drug release. Conclusion: Cocrystals produced using solvent evaporation approach were stable and showed excellent physico-chemical characteristics. The study concluded that the cocrystallization approach would prove to be a successful method to improve physico-chemical and mechanical properties. Keywords: Lopinavir, Ritonavir, Multi-Drug Cocrystals, Solubility, Dissolution.

Solubility and Scale-Up Potency of Norfloxacin-Urea Co-Crystal Prepared by Ultrasound-Assisted Slurry Co-Crystallization Method

Norfloxacin is an antimicrobial in treating urinary tract infections with low water solubility. This study aims to know the effect of norfloxacin-urea co-crystal formation on the solubility of norfloxacin and the potential for scale-up when prepared by ultrasound-assisted slurry co-crystallization method. Identification of the screening result of the norfloxacin-urea (1 : 1) co-crystal formation by a wet grinding method using an ethanol-acetone (1 : 1) solvent mixture was performed by powder X-ray diffractometer (PXRD). The ultrasound-assisted slurry co-crystallization method was used for co-crystal formation with five-fold the weight of norfloxacin and urea than the wet grinding method. The co-crystal product prepared by the ultrasound-assisted slurry co-crystallization method was observed for its crystal morphology and characterized by PXRD and differential scanning calorimeter (DSC). Solubility and dissolution tests in water and acetate buffer solution pH 4.0 were used to evaluate the physicochemical properties. Identification of co-crystal screening by PXRD revealed the formation of norfloxacin-urea co-crystal. The PXRD pattern of the norfloxacin-urea co-crystal product prepared by the ultrasound-assisted slurry co-crystallization method was similar to the wet grinding method. Norfloxacin-urea co-crystal has a different melting point and crystal morphology from pure norfloxacin and urea. The solubility and dissolution rate of norfloxacin-urea co-crystal was higher in water and not significantly different in acetate buffer solution pH 4.0 compared to pure norfloxacin. This study showed that the norfloxacin-urea co-crystal formation could enhance the solubility of norfloxacin in water and had the potential for scale-up when prepared using the ultrasound-assisted slurry co-crystallization method.

Preparations and characterizations of effervescent granules containing azithromycin solid dispersion for children and elder: Solubility enhancement, taste-masking, and digestive acidic protection

Azithromycin, a macrolide antibiotics, is one of the frequently used drugs in the children and elder. However, due to these population difficulty in swallowing and inefficient absorption, and azithromycin inherent poor solubility, bitter taste, and instability in the stomach acidic condition, it is a challenge to reach high oral bioavailability of this drug. To overcome these issues, we developed and characterized the effervescent granules containing azithromycin solid dispersion. Firstly, the solid dispersion was prepared, employing both wet grinding and solvent evaporation methods, with different types/amounts of polymers. The optimal solid dispersion with β-cyclodextrin at a drug:polymer ratio of 1:2 (w/w), prepared by the solvent evaporation method, significantly enhanced the azithromycin solubility 4-fold compared to the free drug, improved its bitterness from “bitter” to “normal”, possessed intermolecular bonding between the drug and polymer, and transformed the azithromycin molecules from crystalline to amorphous state. Secondly, the effervescent granules incorporating the solid dispersion were formulated with varied excipients of sweeteners, gas-generators, pH modulators, and glidants/lubricants. The optimal formula satisfied all the properties stated in the Vietnamese Pharmacopoeia. In summary, the final effervescent granules product could be further investigated in in-vivo and in clinical settings to become a potential azithromycin delivery system with high bioavailability for the children and elder.

Green activating silica-alumina insoluble phase of fly ash to synthesize zeolite P with high adsorption capacity for Pb(II) in solution

Using fly ash as a raw material to synthesize zeolite is an effective way to obtain cheap adsorbent. However, the high energy consumption of activating the insoluble silica-alumina phase of fly ash limits its practical application. In this study, a low-energy, wet-grinding hydrothermal method was used to activate the insoluble phase of fly ash to synthesize zeolite P, and the adsorption capacity of zeolite for lead ion in solution was studied. Wet-grinding can reduce fly ash particle size to nanometer scale and break long-chain Q4(Al) into short-chain low-polymer. Without aging, the activated material could directly synthesize zeolite P with a relative crystallinity of 89.37 %. Compared with the common alkali-fusion method, the wet-grinding method reduced energy consumption by 45.93 % and increased synthetic zeolite relative crystallinity by 7.51 %. The synthesized zeolite P could effectively remove Pb2+ ions from solution through ion exchange and hydroxyl reaction, and the adsorption capacity reached 497.01 mg/g.

Hydration and rheology of activated ultra-fine ground granulated blast furnace slag with carbide slag and anhydrous phosphogypsum

In this study, two different ultra-fine ground granulated blast furnace slag referred to as GS (i.e., by dry-winnowing method) and WS (i.e., by wet-grinding method) were obtained, and the hydration and rheology of activated ultra-fine ground granulated blast furnace slag (activated-BFS) with carbide slag and anhydrous phosphogypsum (AG) as combined activator were systematically investigated by means of setting time, workability, rheological behavior, compressive strength, autogenous shrinkage, electrical resistivity, SEM, XRD and TG-DTG. The results showed that the limiting factor is the BFS type, and not the AG dosage in terms of setting time, and their rheological behavior fitted with H–B model. WS and increase in AG dosage significantly reduced the plastic viscosity, shear stress and yield stress of activated-BFS pastes. The WS presented higher initial reaction activity that generated more hydrates in the early age, restricting the further hydration of BFS particles especially when AG dosage exceeded 10%, thus leading to the different compressive strength development trends between mixtures containing WS (WS/A) and GS (GS/A). The compressive strength of GS/A mixtures increased with increasing AG dosage and reached 39.9 MPa at 3 days, while WS/A first increased and then decreased. The activated-BFS with carbide slag and AG is technically feasible to be employed as cementitious materials in the production of concrete.