Wet Grinding Method Research Articles

Characterization of dye-sensitized solar cells based on various CaCO3-doped ZnO photoanodes prepared using wet powder mixing and grinding

The effects of different doping contents of calcium carbonate (CaCO3) on the performance of zinc oxide (ZnO)-based dye-sensitized solar cells (DSSCs) have never been discussed. In this paper, ZnO nanopowder and CaCO3 nanopowder at different weight percentage concentrations (0–9 wt%) were made into the photoanodes of DSSCs using the wet powder mixing and grinding method. The CaCO3/ZnO DSSC doped with 3 wt% CaCO3 had the highest short-circuit current density (4.35 mA/cm2) and photovoltaic conversion efficiency (1.18%), higher than the short-circuit current density of the reference ZnO-based DSSC by 52%, and the photovoltaic conversion efficiency by 46%. It was found that the photoanodes prepared by doping a small amount of CaCO3 into ZnO could enhance the photoelectric properties of ZnO-based DSSC effectively. The characterization of the CaCO3/ZnO DSSCs were carried out via the measurement of scanning electron microscope (SEM), contact angle (CA) and photocurrent density-voltage (J-V) characteristics. A theoretical background based on charge transport and interfacial recombination was provided to elucidate the process and was tried to explain the mechanism of CaCO3/ZnO DSSC. Although the efficiency of CaCO3/ZnO DSSC still has much room for improvement, the related processes and mechanisms behind this device have considerable research and/or reference value.

Preparation and characterisation of mango bark and mango leaf nanoparticles

Nanoparticles are the simplest form of structures with sizes in the nanometre range (<100 nm). Suspended nanoparticles (non-bio) in base fluids (nanofluids) increase the heat transfer properties of the base fluids. However, addition of nanoparticles to the base fluid increases viscosity as well as pressure drop. It is also expensive to produce non-bio nanoparticles. Thus, mango barks and leaves were used to produce bio nanoparticles due to their natural characteristics that might lower viscosity of the nanofluid. The mango bark and mango leaf were collected and dried under hot sun to remove moisture content until constant weight achieved. Then, the materials were crushed and sieved to obtain finest powder followed by wet grinding for 1 hour at 800 rpm using FRTSCH Planetary Micro Mill PULVERISETTE 7 premium line. The particles size was determined using FESEM and particle size analyser machine. The bulk density of the nanoparticles was determined by experiment. The obtained results showed that the mango barks have lost total weight of 504g (63%) after 8 days of drying. Meanwhile, mango leaves have lost total weight of 606g (78%). The bulk density of mango bark nanoparticles is 2505.00kg/m3 and mango tree leaf nanoparticles is 2108. 00kg/m3. From image analysis using FESEM, the average size of mango bark nanoparticles is around 102 nm and mango leaf nanoparticles was around 132 nm. From particle size analyser, the average fineness of mango bark nanoparticles measured by intensity was 125.5nm and mango leaf nanoparticles was 206.1nm. In conclusion, the mango bark and mango leaf nanoparticles can be synthesised by wet grinding method.

Study on the mechanical activation of malachite and the leaching of complex copper ore in the Luanshya mining area, Zambia

Mechanical activation (MA) of malachite was carried out by dry planetary grinding (DPG) and wet Isa grinding (WIG) methods. When the rotational speed was increased to 400 r/min in DPG, the specific surface area of malachite reached the maximum and the particle size reached the minimum of 0.7–100 µm. Agglomeration occurred between mineral particles when the rotational speed was increased to 580 r/min in DPG. However, no agglomeration was observed among particles with sizes 0.4–3 µm in WIG. X-ray diffraction analysis showed that, at a 580 r/min rotational speed in DPG, the amorphization degree of malachite was 53.12%, whereas that in WIG was 71.40%, indicating that MA led to amorphization and distortion of crystal structures. In addition, in the Fourier transform infrared (FT-IR) spectra of activated malachite, the bands associated with −OH, CO 3 2− and metal lattice vibrations of Cu-O and Cu-OH were weakened, and a new H-O-H bending mode and peaks of gaseous CO2 appeared, indicating that MA decreased the band energy, enhanced dihydroxylation, and increased the chemical reactivity of the malachite. Furthermore, the leaching behavior of copper ore was greatly improved by MA.

Increased bioaffinity and anti-inflammatory activity of florfenicol nanocrystals by wet grinding method

Context: The main objective of the current study is to improve the water solubility of florfenicol (FF) and evaluate changes in its pharmacokinetics and anti-inflammatory activity.Materials and methods: Florfenicol nanocrystals (FF-NC) were prepared by wet grinding combined with spray drying. The characterisations, pharmacokinetics, and anti-inflammatory activity of FF-NC were evaluated.Results: The particle size, polydispersity index (PDI), and zeta potential of FF-NC were 276.4 ± 19.4 nm, 0.166 ± 0.011, and –18.66 ± 5.25 mV, respectively. Compared with FF, FF-NC showed a better dissolution rate in media at different pH. Pharmacokinetic experiments showed the area under the curve (AUC0–t), maximum concentration (Cmax), and mean residence time (MRT) of FF-NC were about 4.62-fold, 2.86-fold, and 1.68-fold higher compared with FF, respectively. In vitro anti-inflammatory experiments showed that FF inhibited the secretion of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), and synthesis of NO in a dose-dependent manner, while FF-NC showed a stronger anti-inflammatory effect than FF under the same dose.Conclusion: FF-NC are an effective way to improve the bioaffinity and anti-inflammatory effects of FF.

Influence of grinding on the pozzolanic activity of granite residue

Abstract This study explores the potential of the granite residue to be applied as a supplementary cementitious material. Furthermore, the efficiency of grinding methods in the improvement of the residue reactivity was also evaluated. The granite residue was collected in a facility located in Brazil and used as a Portland cement replacement with a substitution rate of 25% in mass. The residue was submitted to wet, dry and additive dry grinding methods, with several different times. The cement-based composites were characterized by quantitative X-Ray diffraction using the Rietveld's method, thermogravimetric analysis, and compressive strength. In conclusion, there was observed a higher efficiency of the wet grinding method, followed by an increase in compressive strength results as grinding time increased. Furthermore, the portlandite content was lower in the cement-based composite with granite residue, especially in the samples ground for 60, 120, and 180 minutes; a fact that summed up with other results for the pozzolanic potential of the granite residue.

Development and Application of Seed Coating Agent for the Control of Major Soil-Borne Diseases Infecting Wheat

In order to reduce the usage amount of pesticide fertilizers and protect the natural environment, seed coating agents are receiving increased wide concern. In this study, the active constituent (pesticide) and inactive components (surfactants and film former) of the seed coating agents were screened and optimized by the wet sand processing superfine grinding method. The fungal inhibition test of pesticides showed that thifluzamide, fludioxonil, pyraclostrobin, and difenoconazole have an obvious fungal inhibitory effect on wheat sharp eyespot, take-all, and root rot. LAE-9 and polyacrylamide + carboxymethyl cellulose (CMC) is recommended for the safe surfactant and film former, respectively, based on the seed germination test. Moreover, 6% difenoconazole · fludioxonil flowable concentrate for seed coating (FSC) stimulates the seedling growth of wheat, advances the growth of root, and improves biomass in the field trial, meanwhile, the control efficiency reached above 80%. Thus, we suggested it can be used as an effective seed coating agent for the control of soil-borne diseases in wheat. The seed coating agent has the characteristics of disease prevention, increasing crop yield, and safety of environment, which is of significance in practical application.

Fabrication of Native and Enzymatically Modified Durian Seed (Durio zibethinus Murr.) Starch

Durian seed (Durio zibethinus Murr.) has a high starch content (46.2%) and thus can be used as a new source of starch for the raw materials of pharmaceutical and food industries. In this study, we fabricated native and enzymatically modified durian seed starch using a rough enzyme extract from Saccharomycopsis fibuligera. Wet grinding method was used for starch production. Physicochemical characterization of the starches was investigated by organoleptic, acidity-basicity, loss on drying, flow capability, compressibility, ash content and microbial limit. In addition, viscoamylograph had been done to clarify the viscosity properties of the starches. The result of starch production showed that the durian seed had a starch yield of 17.68%. Physicochemical characterization of the starch showed that the results of quality testing had fulfilled the Indonesian Pharmacopoeia 4th edition standards requirements, such as description, identification, acidity-basicity, loss on drying, ash content and microbial limit. In addition, viscoamylograph study showed that the enzymatically modified durian seed starch had a higher viscosity than the native durian seed starch. Interestingly, modification of the durian seed starch using a rough enzyme extract improved its flow capability and compressibility. These results suggest that the modified durian seed starch experienced an increase in viscosity, compressibility and flow capability compared to native durian starch. Keywords: durian, seed, starch, enzymatic modification

PRODUKSI BIOETANOL DARI BUAH BEBERAPA JENIS MANGROVE DI PAPUA

Mangrove plant has played important role in Papua, both to support the health of ecosystem and the livelihood of its community. As of now, there is only limited knowledge on the utilization of mangroves in Papua. Several varieties in Papua are known to contain carbohydrate and cellulose that can be used to produce food or bioethanol. This study aimed to examine the production of bioethanol using dry grinding and wet grinding methods. The varieties of mangroves used in this research were Rhizophora mucronata Lmk., Rhizophora stylosa Griff., and Bruguiera gymnorrizha. The content of bioethanol as well as the shape and dimension of these varieties were measured in this study. The shape of the mangroves fruit was cylindrical. The mass averages of these mangroves were 180.80 g, 40.39 g and 37.62 g, respectively. The length of the mangrove fruits were 72.33 cm, 41.00 cm and 23.33 cm respectively. The result of the research showed that the best method to produce bioethanol from mangrove fruit was the dry grinding method which resulting in average bioethanol content 6% v/m. Rhizophora stylosa Griff produced the highest bioethanol content, 9.26% v/m, using the dry grinding method and 7.14% with the wet grinding method. Keywords:mangrove fruits, bioethanol, dry grinding,wet grinding

Spray-drying synthesis of Li4Ti5O12 microspheres in pilot scale using TiO2 nanosheets as starting materials and their application in high-rate lithium ion battery

Spray-drying technique has been widely used for synthesis of energy storage materials due to its low cost and easy scale up. However, in mass production, this method usually suffers from the incomplete solid-state reaction owing to the aggregation or poor reactivity of precursors caused by their large particle size and unfavorable morphology. In this study, spinel Li4Ti5O12 (LTO) has been synthesized by using TiO2 nanosheets as precursor through spray-drying for large-scale production. The TiO2 nanosheets are prepared via a facile and scalable wet grinding method. The high aspect ratio TiO2 nanosheets can efficiently reduce the diffusion length of Li element during the solid-state reaction leading to higher reactivity. It has been found that the temperature required for the formation of LTO phase can be significantly reduced by using the two-dimensional (2D) TiO2 nanosheets as starting materials. As a result, through a pilot-scale spray drying process, the LTO reacted from the TiO2 nanosheets shows a pure spinel structure due to the better morphology of TiO2 nanosheets. In contrast, using the unprocessed TiO2 as precursor, the resulting LTO still reveals other impure phases leading to a poor electrochemical performance. The pure LTO shows a higher discharge capacity of ∼160.8 mAh/g at 0.1 C, with an excellent rate performance and superior cycling life in comparison with the LTO containing impurity phases.

Preparation of CaCO₃-TiO₂ Composite Particles and Their Pigment Properties.

CaCO3-TiO2 composite particles were prepared with calcium carbonate (CaCO3) and TiO2 in stirred mill according the wet grinding method. The pigment properties, morphology, and structure of CaCO3-TiO2 composite particles and the interaction behaviors between CaCO3 and TiO2 particles were explored. In the CaCO3-TiO2 composite particles, TiO2 is uniformly coated on the surface of CaCO3 and the firm combination between CaCO3 and TiO2 particles is induced by the dehydration reaction of surface hydroxyl groups. CaCO3-TiO2 composite particles have similar pigment properties to pure TiO2. The hiding power, oil absorption, whiteness and ultraviolet light absorption of composite particles are close to those of pure TiO2. The application performance of CaCO3-TiO2 composite particles in the paint is consonant with their pigment properties. The contrast ratio of the exterior paint containing CaCO3-TiO2 composite particles is equivalent to that of the paint containing the same proportion of pure TiO2.

Water Soluble Octenyl Succinylated Cassava Starch‐Curcumin Nanoformulation With Enhanced Bioavailability and Anticancer Potential

The present study reports the preparation and evaluation of a water soluble octenyl succinylated cassava starch‐curcumin nanoformulation with enhanced bioavailability and anticancer potential. The major drawback of curcumin as a bioactive compound is its poor aqueous solubility and the resultant low bioavailability. In this study, curcumin has been incorporated in octenyl succinate cassava starch by a wet grinding method and the product is characterized by Fourier transform infra red spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), atomic force microscopy (AFM), and X‐ray diffraction (XRD) analyses. The OSA starch loaded nanocurcumin is found to be non‐toxic to L929 cells, but shows anti‐cancer potential to HeLa cells. A significant enhancement in cellular uptake also can be achieved for the OSA starch loaded nanocurcumin as revealed by fluorescence microscopy. The in vitro release of curcumin from the nanostarch matrix is more controlled at simulated intestinal pH than that at gastric pH. Pharmacokinetic study shows that bioavailability of nanocurcumin is increased by about 71.27%.

Preparation and Evaluation of Progesterone Nanocrystals to Decrease Muscle Irritation and Improve Bioavailability.

Progesterone (PG) is a crucial immunomodulatory agent during early pregnancy, and nowadays PG oil-based injection (PG/OI) has a huge market all over the world. However, PG/OI may accumulate the local muscle and further cause irritations after long-term administration. In this study, PG nanocrystals (PG/NCs) injection was developed to decrease muscle toxicity. PG/NCs injection containing 10% (w/v) PG was first prepared using a wet grinding method. Then, particle size, zeta potential, morphology powder, X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) studies were carried out to evaluate the characteristics of dosage form. The rabbit muscle irritation, hemolysis, and rat pharmacokinetics tests were used to estimate the in vivo characteristics of PG/NCs. The results showed that the mean particle size and the zeta potentials of NCs were 299.5 ± 9.0nm and - 36.8 ± 1.5mV, respectively. The crystalline state of PG/NCs was not altered during particle size reduction according to PXRD, DSC, and FTIR results. Muscle irritation presented that PG/NCs had lower irritation than that of PG/OI. Hemolysis test suggested that PG/NCs injection was functioned without hemolysis and red cell agglutination. The pharmacokinetics study showed that the AUC0-t and Cmax of PG/NCs was 3.2-fold (p < 0.05) and 3.1-fold higher than PG/OI, which demonstrated that PG/NCs injection had greater bioavailability than PG/OI. Therefore, it was obvious that PG/NCs injection exhibited a lower muscle irritation, hemolysis rate, and higher bioavailability, which was a better dosage form than OI.

Fabrication and Analysis of Vanadium-Based Metal Powders for Selective Laser Melting

Vanadium Alloy is a type of advanced nuclear material with many ideal properties compared as traditional nuclear materials, which has very wide and important application in first-wall and blanket structural material for fusion power plant applications. So it has attracted increasing attentions, especially on new manufacturing methods, such as selective laser melting and so on. In this paper, the comparative study of the powders obtained by mechanical mixing method, dry grinding method and wet grinding method respectively was performed to evaluate the effect of ball milling process on the microstructure and degree of alloying of the vanadium-based powder mixtures with the nominal composition of V5Cr5Ti vanadium alloy. The powders prepared by dry grinding method exhibits better spherical-like morphology and degree of alloying than those prepared by mechanical mixing method and wet grinding method, which indicates that dry grinding method can be used to prepare the superfine vanadium alloy powders for selective laser melting. This work provides a new method as well as important insights into the preparation of superfine vanadium alloy powders for selective laser melting additive manufacturing technology.

Edges of graphene and carbon nanotubes with high catalytic performance for the oxygen reduction reaction.

We invented a practical and simple wet-grinding method to break conventional graphene sheets and CNTs for the production of new graphene/CNTs with adequate edge density (about 25 000 atoms per graphene-fragment of about 1 μm2 in size) and no detectable changes in intrinsic defects, extrinsic impurities, and even surface-area. Measurements using the standard cyclic voltammetry, rotating disk electrode and rotating ring-disk electrode techniques all confirm that such mildly fragmented graphene, as well as carbon-nanotubes treated similarly using this wet-grinding method, can facilitate the fast 4-electron oxygen reduction reaction (ORR) pathway. Our first-principles computational studies of the ORR on graphene, as well as the relevant known data in the literature, support an intriguing proposition that the ORR can be speeded up simply by increasing the edge-density of graphene. The adsorption of O2 involving both oxygen atoms, which causes O-O elongation, is best facilitated at the edge of graphene, facilitating a multi-step 4-electron ORR process.

벌 화분에서 습식 나노화 공정에 의한 유효성분의 추출

Bee pollen is produced by honeybees and is considered one of the most balanced and nourishing nutritional supplements available. Historically, bee pollen has been prescribed for its healing properties and consumed for its high-energy supply. Recent research has provided evidence that bee pollen has diverse biological activities, such as anti-oxidant, anti-inflammatory, anti-bacterial, and even anti-cancer effects. However, the outer membrane of the pollen grain, exine, is highly resistant to most acidic solutions, high pressure, and even digestive enzymes, and the resulting low bioavailability limits its nutritional and clinical applications. This study applied a wet-grinding method to destroy the exine effectively, and it then examined the pollen’s enhanced biological activity. First, microscopic observations provided strong evidence that wet grinding destroyed the exine time-dependently. In addition, the content of polyphenols, well-known ingredients of bee pollen and used as internal standards for the quality control of commercial pollen preparations, increased up to 11-fold with wet grinding. Further, the anti-oxidant activity demonstrated on the ABTS anti-oxidant assay, as well as the DPPH radical scavenging assay, was also dramatically increased. Together, the results presented here support a new technology by which bee pollen can be used as a resource for medical, nutritional, and cosmetic applications.

Dissolution Behaviour of Hazardous Materials from Steel Slag with Wet Grinding Method

Steel slag is a by-product from steel industry and it contains variety of hazardous materials. In this study, the dissolution behaviour and removal potential of hazardous materials from steel slag with the wet grinding method was investigated. The slag was wet ground in the CO2 atmosphere and the slurry produced was filtered using centrifugal separator to separate the liquid and solid sediments. Then, the concentrations of dissolved metal elements in the liquid sediment were analyzed by ICP-MS. The changes of pH during the grinding were also investigated. It was found that the pHs were decreased immediately after the CO2 gas introduced into the vessel. The pHs were ranging from 6.8 to 7.6 at the end of grinding. The dissolved concentration of Zn and Cr were ranging from 5~45 [mg/dm3] and 0.2~2.5 [mg/dm3] respectively. The ratios of Zn removal for stainless steel oxidizing and reducing slag were very high, but those from normal steel oxidizing and reducing slag were very low. It is assumed that the Zn dissolved as ZnOH+ from Zn(OH)2 that formed due to the reaction between ZnO and water. Dissolution of Cr also occurred but in very low quantity compared to the dissolution of Zn. The dissolution of Cr occurred due to the grinding process and small amount of Cr(OH)3 was formed during the grinding. This small formation of Cr(OH)3 resulted to the low dissolved concentration of Cr in the form of Cr(OH)2+. According to the XRD analysis, the Cr mostly existed in the slags as Cr(IIl) in the form of MgCr2O4 and FeCr2O4.

Characterization of the Oum El Khacheb phosphorites (South Tunisia) and enrichment of big rejections by grinding

In the last decade, the phosphate reserves have started to decrease. In this study, both phosphate of Oum El Khacheb’s (O.E.K) region (South of Tunisia) and its big rejections were characterized mineralogically and chemically by several analysis methods such as the binocular magnifying glass, X-rays diffraction technique, Technicon auto-analyzer, atomic absorption spectroscopy, and carbon sulfur analyzer. Then, this work focuses on the coarse rejections of O.E.K’s phosphorites which can be valorized by the wet grinding method. Therefore, we have used the methodology of experimental research to determine the optimal grinding conditions. Results found by Doelhert matrix are: a duration at about 4min, a pulp on solid concentration of 45.00%, a number of cycles equals to 60rpm and 3.87 as the jar’s loading. The enhancement of the weight yields of phosphate recuperation increased significantly by 46.39% from big rejections with 24.60% of P2O5 concentration.

Study on Enhanced Dissolution of Azilsartan-Loaded Solid Dispersion, Prepared by Combining Wet Milling and Spray-Drying Technologies.

The purpose of this study was to develop a combination method of wet milling and spray-drying technologies to prepare the solid dispersion and improve the dissolution rate of poorly water-soluble drug candidates. Azilsartan (AZL) was selected as the model drug for its poor water solubility. In the study, AZL-loaded solid dispersion was prepared with polyethylene glycol 6000 (PEG6000) and hydroxypropyl cellulose with super low viscosity (HPC-SL) as stabilizers by using combination of wet grinding and spray-drying methods. The high AZL loading solid dispersion was then characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and Fourier transform infrared spectroscopy (FTIR). Besides, dissolution test was carried out by the paddle method and stability investigation was also conducted. As a result, the dissolution rate of the solid dispersion tablets was found to be greater than conventional tablets, but in close agreement with market tablets. Furthermore, the formulation was shown to be stable at 40 ± 2°C and 75 ± 5% for at least 6months, owing to its decreased particle size, morphology, and its crystal form. It was concluded that the combination of wet milling and spray-drying approaches to prepare solid dispersion would be a prospective method to improve the dissolution rate of poorly water-soluble drugs.

THE PREPARATION AND SOLUBILITY OF LORATADINE-FUMARIC ACID BINARY MIXTURE

ABSTRACTObjective: Loratadine (LOR) is a biopharmaceutics classification system Class II drug that has low solubility and high permeability, so its absorptionrate is determined by the dissolution rate. The aim of this study was to prepare an LOR-fumaric acid (LOR-FUM) binary mixture and to investigate itsinfluence on the solubility and dissolution rate of LOR.Methods: LOR-FUM binary mixture was prepared by the wet grinding method in an equimolar ratio by the addition of two drops of methanol.Characterization of LOR-FUM binary mixture was conducted by the construction of the phase solubility, powder X-ray diffractometry, Fouriertransforms infrared spectroscopy, and polarizing microscopy methods. Solubility test was performed in water at room temperature, whereas thein vitro dissolution test was performed in the pH 1.2, 4.5, and 6.8 buffer solutions.Results: The phase solubility curve of LOR in FUM solution is similar to type B. The powder X-ray diffraction results show the crystallinity of LOR waschanged become more amorphous indicating the salt formation. Fourier transforms infrared spectroscopy (FTIR) spectra of LOR-FUM binary mixtureshowed the vibration peaks of an imine group on the pyridine ring of LOR and carbonyl group on the FUM are not detected. On the other hand, thepolarizing microscope images showed the crystal habit of LOR-FUM binary mixture after recrystallized from methanol contrast to crystal habit ofits pure components. The solubility in water of LOR-FUM binary mixture was higher than pure LOR. Amount of LOR released from LOR-FUM binarymixture in pH 4.5 and 6.8 buffer solutions was faster than from pure LOR.SConclusion: A binary mixture of LOR and FUM may improve the solubility and dissolution rate of LOR.Keywords: Loratadine, Fumaric acid, Binary mixture, Solubility, Dissolution rate.

The Effect of Variety and Processing Methods on the Functional and Chemical Properties of Rice Flour

The effect of varieties, local (Abakalike) and foreign (Mama Gold) and two processing methods, semi-dry and wet grinding methods on the characteristics of rice flour were investigated. Functional and chemical properties of the rice flour were analyzed using standard methods. The functional parameters analyzed were dispersibility, relative bulk density, swelling power and water absorption capacity while chemical parameter were moisture content, protein, ash, sugar, starch, amylase and amylopectin. The parameters were influenced by variety and processing methods. Highest dispersibility, relative bulk density and swelling power values were associated with sample A which is the foreign variety, while solubility and water absorption capacity were associated with sample B, which is the local variety, all processed by the semi-dry grinding method. The semi-dry ground rice flour produced highest protein and ash as seen in sample B, while wet milled rice flour were associated with highest moisture and starch contents. The flour produced from the local rice (Abakalike) had highest protein, ash sugar and amylose over the foreign variety with all the parameters showing significant differences.