Size-dependence hydrophobicity in nanocrystalline talc produced by high-intensity planetary ball milling

2015 ◽  
Vol 1805 ◽  
Author(s):  
Rebeca Caban-Nevarez ◽  
Oscar J Perales Perez
Keyword(s):  
Particle Size ◽  
High Intensity ◽  
Ball Mill ◽  
Size Dependence ◽  
Particle Size Reduction ◽  
Angle Measurements ◽  
Micron Size ◽  
Contact Angle Measurements ◽  
Planetary Ball Milling ◽  
Hydrophilic Character

ABSTRACTMicron-size talc samples were ground using a high-intensity planetary ball mill at different milling times as an attempt to reduce particle size and study the effect on the corresponding hydrophobicity. XRD and SEM results confirmed the decrease in the particle size. FTIR spectroscopy analyses revealed the talc characteristic bands centered on 669 cm-1 for the O-H bonds and 1018 cm-1 for the Si-O bonds, as well as a degradation in the talc structure for prolonged milling times. BET results indicate an increase of specific surface area, which also confirms particle size reduction, reaching a maximum at 1 h, after which the particles agglomerate. Contact angle measurements show a decrease in the hydrophobicity of talc after milling. Although talc retains its hydrophobicity after short milling periods, prolonged grinding causes the mineral to have a more hydrophilic character.

Effects of Pretreatment Methods on the Enamel Surface Improving Sealant Adhesion

2019 ◽  
Vol 40 ◽  
pp. 92-100
Author(s):  
Adina Rotaru-Birgaoanu ◽  
Teodora Teslaru ◽  
R. Ionut Olariu ◽  
Ionut Chirap ◽  
Liliana Sachelarie ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Diffuse Reflectance ◽  
Enamel Surface ◽  
Acid Etching ◽  
Minimum Level ◽  
Angle Measurements ◽  
Physical Chemical ◽  
Contact Angle Measurements ◽  
Hydrophilic Character ◽  
Yellow Index

Is PlasBeam pretreatment an efficient method to improve sealant adhesion onto the enamel surface?The aim of this study isto investigate the effects induced by three pretreatment techniques used to improve sealant adhesion on the enamel surface, respectively standard acid-etching, UV radiations and a new method based on plasma operating at atmospheric pressure, namely the PlasBeam method.The physical-chemical modifications induced onto the enamel surface by the above pretreatments were analyzed using Contact Angle Measurements and Diffuse Reflectance Spectroscopy.The changes in the enamel surface morphology show that the acid-etching pretreatment is mostly efficient in increasing roughness, but this method stimulates the degradation processes that are well-known and turns down the brillianceof the treated surface. On the other hand, the PlasBeam treatment brings a higher roughness at the contact area between sealant and the enamel surface, compared to the UV radiations pretreatments.Moreover, the PlasBeam improves the hydrophilic character of enamel as a practical solution in enhancing the sealant adhesion to the surface. Related to other effects, it has been noticed that thePlasBeam method generates the most reflective enamel surface, whereas the White/Yellow index reaches the minimum level after a 10 second treatment.

Evaluation of particle size reduction and agglomeration in dry grinding of natural quartz in a planetary ball mill

2020 ◽  
Vol 368 ◽  
pp. 149-159 ◽  
Author(s):  
Pedro L. Guzzo ◽  
Filipe B. Marinho de Barros ◽  
Bruno R. Soares ◽  
Juliano B. Santos
Keyword(s):  
Particle Size ◽  
Ball Mill ◽  
Size Reduction ◽  
Planetary Ball Mill ◽  
Natural Quartz ◽  
Particle Size Reduction ◽  
Dry Grinding

scholarly journals Micron-Size White Bamboo Fibril-Based Silane Cellulose Aerogel: Fabrication and Oil Absorbent Characteristics

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1407 ◽  
Author(s):  
Dinh Nguyen ◽  
Cuong Vu ◽  
Huong Vu ◽  
Hyoung Choi
Keyword(s):  
Dry Weight ◽  
Urea Solution ◽  
Water Contact ◽  
Cellulose Aerogel ◽  
Angle Measurements ◽  
Micron Size ◽  
Contact Angle Measurements ◽  
Absorption Performance ◽  
Oil Absorbent ◽  
Highly Porous

Micron-size white bamboo fibrils were fabricated from white bamboo and used as a source for the production of highly porous and very lightweight cellulose aerogels for use as a potential oil absorbent. The aerogels were fabricated through gelation from an aqueous alkali hydroxide/urea solution, followed by a conventional freeze-drying process. The morphology and physical properties of the aerogels were characterized by field emission scanning electron microscopy and Brunauer–Emmett–Teller surface area analysis, respectively. Successful silanization of the cellulose aerogel was confirmed by energy-dispersive X-ray spectroscopy, Fourier-transform infrared spectroscopy, and water contact angle measurements. The fabricated silane cellulose aerogel exhibited excellent absorption performance for various oil and organic solvents with typical weight gains ranging from 400% to 1200% of their own dry weight, making them promising versatile absorbents for a range of applications, including water purification.

Hydrogen and its effect on the grinding of Ti-Ni powder

2021 ◽  
Vol 23 (3) ◽  
pp. 100-111
Author(s):  
Ekaterina Abdulmenova ◽  
◽  
Sergey Kulkov ◽  
Keyword(s):  
Particle Size ◽  
Dislocation Density ◽  
High Intensity ◽  
Ball Mill ◽  
Mechanical Treatment ◽  
Average Particle Size ◽  
Lattice Parameter ◽  
Planetary Ball Mill ◽  
Average Particle ◽  
X Ray

Introduction. Industrial nickel-titanium alloy PN55T45 closed to the equiatomic composition is widely used for the manufacture of products by powder metallurgy. To achieve high physical and mechanical properties of the material obtained by this method, it is necessary to use fine powders, which can be obtained by implementing high-intensity grinding in a planetary ball mill. However, during such treatment, contamination, powder oxidation and particle aggregation, etc. are possible. To solve this problem, preliminary hydrogenation is proposed for subsequent grinding in a planetary ball mill. The aim of the work is to study the effect of hydrogen on the grinding of titanium nickelide powder. Materials and methods. The morphology and average particle size of the powders were studied by scanning electron microscopy. The structure and phase composition of the powders were investigated by the methods of X-ray structural and X-ray phase analysis. The data of X-ray structural analysis were used to estimate the dislocation density. Results and discussions. It is shown that the use of pre-hydrogenation for 180 minutes before machining allows reducing the average particle size by about a half. After mechanical treatment of the powder, the parameters of the crystal lattices of the TiNi (austenite), Ti2Ni and Ni3Ti phases do not change within the error range. After mechanical treatment of the powder with preliminary hydrogenation, the crystal lattice parameter of only the Ti2Ni phase changes significantly, in particular, at 180 minutes of hydrogenation, the lattice parameter increases to 1.1457 ± 5×10-4 nm, which corresponds to the stoichiometry of the Ti2NiH0.5 hydride with a lattice parameter of 1.1500 nm. The highest dislocation density estimated by X-ray diffraction analysis is contained in the Ti2Ni (511) phase than in the TiNi (austenite) (110) and Ni3Ti (202) phases. Thus, preliminary hydrogenation can be an effective method of powder grinding due to the formation of brittle hydride and suppression of the aggregation of fine particles during high-intensity mechanical treatment.

scholarly journals Effect of ash existence in the coal particles on the dewatering performance of fine coal

2020 ◽  
Author(s):  
Suhong Zhang ◽  
Ni Gao ◽  
Ke Zhao
Keyword(s):  
Contact Angle ◽  
Particle Size ◽  
Moisture Content ◽  
Coal Sample ◽  
Ash Content ◽  
Primary Role ◽  
Fine Coal ◽  
Angle Measurements ◽  
Coal Particles ◽  
Contact Angle Measurements

Abstract The dewatering experiments of fine coal with different ash contents in the particle size range of 0.125 mm − 0 mm were investigated in this study. Structures of coal samples were characterized by X-ray diffractometer (XRD) and surface functional groups were detected by Fourier transform infrared (FTIR). Wettability and wetting heats of coal samples were determined by contact angle measurements and micro-calorimeter system, respectively. In this study, the dewatering results indicate that the ash content of fine coal had less effect on the coal dewatering than the coalification degree in the dewatering process. However, for the given coal sample the moisture content was significantly affected by the ash content while the coal particle size was less than 0.125 mm. The decrease of moisture content in coal sample after the ash was removed indicating that the hydrophobic property of coal surface was enhanced based on contact angle measurements and wetting heats. In addition, kaolinite played a primary role of minerals in coal for the coal dewatering.

Ceramic Micro/Nanoparticle Size Evolution in Wet Grinding in Stirred Ball Mill

2004 ◽  
Vol 126 (4) ◽  
pp. 779-786 ◽  
Author(s):  
Jiann-Cherng Su ◽  
Steven Y. Liang ◽  
Wang Lin Liu ◽  
Tzu Chi Jan
Keyword(s):  
Particle Size ◽  
Ball Mill ◽  
Reduction Rate ◽  
Ceramic Materials ◽  
Size Reduction ◽  
Nanoparticle Size ◽  
Balance Model ◽  
Particle Size Reduction ◽  
Model Predictions ◽  
Stirred Ball Mill

Micro- and nanostructured ceramic materials have received increasing attention in light of the attainable mechanical properties of the resulting components, parts, and products. Stirred ball mill grinding is an important process in reducing the size of ceramic micro- and/or nanoparticles to a desirable range to be used as a constituent for micro- and nanostructured materials. In this study, the time change of particle size of titanium dioxide TiO2 micro- and nanoparticles in the stirred ball mill grinding process is characterized with a fracture mechanics analysis combined with a population balance model. The approach provides both the mean and the statistical distribution of particle sizes produced by ball grinding. It also yields an estimate for the amount of time necessary to achieve a desired particle size. The model examines the effects of process parameters, including the grinding speed, the viscosity of the suspending fluid, and the concentration of the feed as input variables. Experiments performed with TiO2 suspended in ethylene glycol are used for comparison to model predictions for validation. The results show that the initial particle-size reduction rate is relatively high, however, as the particle size decreases, the time required for further reduction increases significantly. Good agreement exists between the model predictions and the experimental results in the context of micro- and nanoparticle-size reduction trends.

scholarly journals Effects of Ball Size on the Grinding Behavior of Talc Using a High-Energy Ball Mill

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 668 ◽  
Author(s):  
Hyun Na Kim ◽  
Jin Woo Kim ◽  
Min Sik Kim ◽  
Bum Han Lee ◽  
Jin Cheul Kim
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Ball Mill ◽  
High Energy ◽  
Industrial Applications ◽  
Particle Size Reduction ◽  
Ball Size ◽  
High Energy Ball Mill ◽  
Spherical Diameter ◽  
Energy Ball

The properties and preparation of talc have long been investigated due to its diverse industrial applications, which have expanded recently. However, its comminution behavior is not yet fully understood. Therefore, having better control of the particle size and properties of talc during manufacturing is required. In this study, we investigate the effect of the ball size in a high-energy ball mill on the comminution rate and particle size reduction. High-energy ball milling at 2000 rpm produces ultrafine talc particles with a surface area of 419.1 m2/g and an estimated spherical diameter of 5.1 nm. Increasing the ball size from 0.1 mm to 2 mm increases the comminution rate and produces smaller talc particles. The delamination of (00l) layers is the main comminution behavior when using 1 mm and 2 mm balls, but both the delamination and rupture of (00l) layers occurs when using 0.1 mm balls. The aggregation behavior of ground talc is also affected by the ball size. Larger aggregations form in aqueous solution when ground with 0.1 mm balls than with 1 mm or 2 mm balls, which highlights the different hydro-phobicities of ground talc. The results indicate that optimizing the ball size facilitates the formation of talc particles of a suitable size, crystallinity, and aggregation properties.

Nanostructured Polymer Brushes With Reversibly Changing Properties

2002 ◽  
Vol 727 ◽  
Author(s):  
Denys Usov ◽  
Manfred Stamm ◽  
Sergiy Minko ◽  
Christian Froeck ◽  
Andreas Scholl ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Phase Segregation ◽  
Water Contact ◽  
Angle Measurements ◽  
Nanostructured Polymer ◽  
Contact Angle Measurements ◽  
Vertical Segregation ◽  
Oxygen Plasma Etching ◽  
Grafting From ◽  
Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

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