Effect of C8mimPF6 on miniemulsion polymerization for application in new latex coating products

C8mimPF6, as a type of room temperature ionic liquid (RTIL) with non-volatility and a low melting point, may replace conventional coalescing agents in latex coatings, thus preventing volatile organic compound (VOC) emissions caused by coalescing agents. In this study, systematic investigations on the effect of various factors including initiator type, initiator concentration, temperature and C8mimPF6 concentration on the conversion of latex and droplet/particle size of a miniemulsion during polymerization have been conducted. The presence of C8mimPF6 has shown to have a marked effect on the reaction rate. Such an effect strongly depends on the type of initiator being used. For polymerization initiated by 2,2-azobis (isobutyronitrile) (AIBN), C8mimPF6 had a promoting effect on the reaction rate at low concentrations, but this effect might be reversed upon certain C8mimPF6 concentrations, e.g. 10 wt%. While initiated by H2O2/Vc, this promoting effect faded even at low C8mimPF6 concentrations. The different limiting factors, which determine the reaction rate with different types of initiator, may contribute to the results. For reactions initiated by hydrophobic AIBN, the reaction was dominated by kinetics. The presence of C8mimPF6 may cause an enhanced chain propagation rate and reduced chain termination rate, which may further contribute to the increase in reaction rate at lower concentrations of C8mimPF6. With hydrophilic H2O2/Vc, the resistance for the transfer of radicals into a droplet/particle might be increased significantly with increasing C8mimPF6 concentration due to a tighter interfacial structure at lower concentrations of C8mimPF6. Thus, such transfer of radicals may become a limiting step whilst the presence of C8mimPF6 increases the transfer resistance on radicals resulting in a decrease in reaction rate. The reaction temperature, which is related to the decomposition temperature of the initiator being used, was another factor affecting the conversion of latex and the size of latex particles. A higher temperature e.g. 50 °C promotes the coalescence of droplets/particles, and hence produces larger latex particles. In the presence of C8mimPF6, the reaction temperature could be significantly reduced to as low as 40 °C, which prevents phase separation. The final particle size depends on the nucleation mechanism as well as the coalescence of droplets/particles during polymerization.

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Catalyzed and Promoted Direct Reaction of Ethyl Chloride with Silicon Using Stirred-Bed Reactor

Baghdad Science Journal ◽

10.21123/bsj.4.3.425-429 ◽

2007 ◽

Vol 4 (3) ◽

pp. 425-429

Author(s):

Baghdad Science Journal

Keyword(s):

Reaction Temperature ◽

Kinetic Data ◽

Reaction Rate ◽

Ethyl Chloride ◽

Direct Reaction ◽

Promoting Effect

In this paper a stirred-bed performed of the copper catalyzed synthesis of ethylchlorosilanes from silicon and ethyl chloride was described. A Si-catalyst mixture prepared by reaction of CuCl and Si was employed. The compositions of products were mainly ethyltrichlorosilane, diethyldichlorosilane, and ethyldichlorosilane and mainly depended on the extent of Cu in the mixture and the reaction temperature. A promoting effect on the extent of adsorption was observed on the addition of certain additives. The kinetic data revealed the direct depended of the reaction rate on C2H5Cl pressure.

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Study on the Decolorization Kinetics of Azo Dye Wastewater by Sponge Iron

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.178-181.450 ◽

2012 ◽

Vol 178-181 ◽

pp. 450-453 ◽

Cited By ~ 1

Author(s):

You Zhang ◽

Zi Chao Wang ◽

Meng Chun Gao ◽

Zong Lian She ◽

Xiao Jing Zhang ◽

...

Keyword(s):

Particle Size ◽

Rate Constant ◽

Reaction Temperature ◽

Azo Dye ◽

Reaction Rate ◽

Reaction Rate Constant ◽

Sponge Iron ◽

Dye Wastewater ◽

Initial Ph ◽

Decolorization Kinetics

A study on the decolorization of azo dye wastewater by sponge iron was carried out in order to establish a model of decolorization kinetics, and to investigate the effects of particle size of sponge iron, the initial pH of azo dye wastewater and reaction temperature on the reaction rate constant. The results showed that the decolorization processes of azo dye wastewater by sponge iron was first order kinetic reaction, and reaction rate constant presented high value on the condition of small particle size of sponge iron, low initial pH of azo dye wastewater and high reaction temperature.

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Chemical Transformation of Fe, Air & Water to Ammonia: Variation of Reaction Rate with Temperature, Pressure, Alkalinity and Iron

10.26434/chemrxiv.6879671.v1 ◽

2018 ◽

Author(s):

Ping Peng ◽

Fang-Fang Li ◽

Xinye Liu ◽

Jiawen Ren ◽

jessica stuart ◽

...

Keyword(s):

Particle Size ◽

Reaction Rate ◽

Electrolyte Concentration ◽

Iron Concentration ◽

Reaction Medium ◽

Iron Particle ◽

Intermediate Step ◽

Ammonia Production ◽

Pure Nitrogen ◽

Alkaline Reaction

The rate of ammonia production by the chemical oxidation of iron, N2(from air or as pure nitrogen) and water is studied as a function of (1) iron particle size, (2) iron concentration, (3) temperature, (4) pressureand (5) concentration of the alkaline reaction medium. The reaction meduium consists of an aqueous solution of equal molal concentrations of NaOH and KOH (Na0.5K0.5OH). We had previously reported on the chemical reaction of iron and nitrogen in alkaline medium to ammonia as an intermediate step in the electrochemical synthesis of ammonia by a nano-sized iron oxide electrocatlyst. Here, the intermediate chemical reaction step is exclusively explored. The ammonia production rate increases with temperature (from 20 to 250°C), pressure (from 1 atm to 15 atm of air or N2), and exhibits a maximum rate at an electrolyte concentration of 8 molal Na0,5K0,5OH in a sealed N2reactor. 1-3 µm particle size Fe drive the highest observed ammonia production reaction rate. The Fe mass normalized rate of ammonia production increases with decreasing added mass of the Fe reactant reaching a maximum observed rate of 2.2x10-4mole of NH3h-1g-1for the reaction of 0.1 g of 1-3 µm Fe in 200°C 8 molal Na0.5K0.5OH at 15 atm. Under these conditions 5.1 wt% of the iron reacts to form NH3via the reaction N2+ 2Fe + 3H2O ®2NH3+ Fe2O3.

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The effect of particle size on the reactivity of active sodium carbonate towards sulfur dioxide

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19793419 ◽

1979 ◽

Vol 44 (12) ◽

pp. 3419-3424

Author(s):

Karel Mocek ◽

Erich Lippert ◽

Dušan Husek ◽

Emerich Erdös

Keyword(s):

Particle Size ◽

Sulfur Dioxide ◽

Sodium Carbonate ◽

Reaction Rate ◽

Active Form ◽

Controlling Factor ◽

Active Sodium ◽

Effect Of Particle Size ◽

Integral Reactor

The effect of particle size (0.33-1.0 mm) of the sodium carbonate on the reactivity of the active sodium carbonate prepared therefrom towards the sulfur dioxide was studied in a fixedbed integral reactor at a temperature of 150 °C. The found dependence of the reaction rate on the particle size exhibits an unexpected course; at sizes of about 0.65 mm, a distinct minimum appears. The reaction rate decreases approximately ten times in the first branch of this dependence. The controlling factor of the reactivity of sodium carbonate, however, remains to be the method of preparing the active form.

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A thermodynamic assessment of precipitation, growth, and control of MnS inclusion in U75V heavy rail steel

High Temperature Materials and Processes ◽

10.1515/htmp-2021-0022 ◽

2021 ◽

Vol 40 (1) ◽

pp. 178-192

Author(s):

Wen-Qiang Ren ◽

Lu Wang ◽

Zheng-Liang Xue ◽

Cheng-Zhi Li ◽

Hang-Yu Zhu ◽

...

Keyword(s):

Particle Size ◽

Rail Steel ◽

Solidification Process ◽

Segregation Ratio ◽

Two Phase ◽

Final Particle ◽

Solid Liquid ◽

And Control ◽

Heavy Rail ◽

Heavy Rail Steel

Abstract Thermodynamic analysis of the precipitation behavior, growth kinetic, and control mechanism of MnS inclusion in U75V heavy rail steel was conducted in this study. The results showed that solute element S had a much higher segregation ratio than that of Mn, and MnS would only precipitate in the solid–liquid (two-phase) regions at the late stage during the solidification process at the solid fraction of 0.9518. Increasing the cooling rate had no obvious influence on the precipitation time of MnS inclusion; however, its particle size would be decreased greatly. The results also suggested that increasing the concentration of Mn would lead to an earlier precipitation time of MnS, while it had little effect on the final particle size; as to S, it was found that increasing its concentration could not only make the precipitation time earlier but also make the particle size larger. Adding a certain amount of Ti additive could improve the mechanical properties of U75V heavy rail steel due to the formation of TiO x –MnS or MnS–TiS complex inclusions. The precipitation sequences of Ti3O5 → Ti2O3 → TiO2 → TiO → MnS → TiS for Ti treatment were determined based on the thermodynamic calculation.

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Grinding Kinetics of Slag and Effect of Final Particle Size on the Compressive Strength of Alkali Activated Materials

Minerals ◽

10.3390/min9110714 ◽

2019 ◽

Vol 9 (11) ◽

pp. 714 ◽

Cited By ~ 6

Author(s):

Evangelos Petrakis ◽

Vasiliki Karmali ◽

Georgios Bartzas ◽

Konstantinos Komnitsas

Keyword(s):

Particle Size ◽

Compressive Strength ◽

Particle Size Distribution ◽

Size Distribution ◽

Ageing Time ◽

Reduction Rate ◽

Curing Temperature ◽

Alkali Activation ◽

Final Particle ◽

Alkali Activated

This study aims to model grinding of a Polish ferronickel slag and evaluate the particle size distributions (PSDs) of the products obtained after different grinding times. Then, selected products were alkali activated in order to investigate the effect of particle size on the compressive strength of the produced alkali activated materials (AAMs). Other parameters affecting alkali activation, i.e., temperature, curing, and ageing time were also examined. Among the different mathematical models used to simulate the particle size distribution, Rosin–Rammler (RR) was found to be the most suitable. When piecewise regression analysis was applied to experimental data it was found that the particle size distribution of the slag products exhibits multifractal character. In addition, grinding of slag exhibits non-first-order behavior and the reduction rate of each size is time dependent. The grinding rate and consequently the grinding efficiency increases when the particle size increases, but drops sharply near zero after prolonged grinding periods. Regarding alkali activation, it is deduced that among the parameters studied, particle size (and the respective specific surface area) of the raw slag product and curing temperature have the most noticeable impact on the compressive strength of the produced AAMs.

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Hydrogen Generation by Hydrolysis of the Ball Milled Al-C-KCl Composite Powder in Distilled Water

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.519.87 ◽

2012 ◽

Vol 519 ◽

pp. 87-91 ◽

Cited By ~ 1

Author(s):

Xia Ni Huang ◽

Zhang Han Wu ◽

Ke Cao ◽

Wen Zeng ◽

Chun Ju Lv ◽

...

Keyword(s):

Particle Size ◽

Reaction Temperature ◽

Fine Particle ◽

Composite Powder ◽

Hydrogen Generation ◽

Aluminum Particle ◽

Generation Rate ◽

Composite Powders ◽

Fine Particle Size ◽

Hydrolysis Of

In the present investigation, the Al-C-KCl composite powders were prepared by a ball milling processing in an attempt to improve the hydrogen evolution capacity of aluminum in water. The results showed that the hydrogen generation reaction is affected by KCl amount, preparation processing, initial aluminum particle size and reaction temperature. Increasing KCl amount led to an increased hydrogen generation volume. The use of aluminum powder with a fine particle size could promote the aluminum hydrolysis reaction and get an increased hydrogen generation rate. The reaction temperature played an important role in hydrogen generation rate and the maximum hydrogen generation rate of 44.8 cm3 min-1g-1of Al was obtained at 75oC. The XRD results identified that the hydrolysis byproducts are bayerite (Al(OH)3) and boehmite (AlOOH).

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Probing the Effect of High Energy Ball Milling on the Structure and Properties of LiNi1/3Mn1/3Co1/3O2 Cathodes for Li-Ion Batteries

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4034755 ◽

2016 ◽

Vol 13 (3) ◽

Cited By ~ 5

Author(s):

Malcolm Stein ◽

Chien-Fan Chen ◽

Matthew Mullings ◽

David Jaime ◽

Audrey Zaleski ◽

...

Keyword(s):

Particle Size ◽

Electrochemical Performance ◽

Crystallite Size ◽

Ball Milling ◽

Lithium Ion ◽

High Energy ◽

Li Ion Batteries ◽

Structure And Properties ◽

Transfer Resistance ◽

Li Ion

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.

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Nitrocellulose Catalyzed With Manganese Oxide Nanoparticles: Advanced Energetic Nanocomposite With Superior Decomposition Kinetics

10.21203/rs.3.rs-311803/v1 ◽

2021 ◽

Author(s):

Sherif Elbasuney ◽

M. Yehia ◽

Shukri Ismael ◽

Yasser El-Shaer ◽

Ahmed Saleh

Keyword(s):

Activation Energy ◽

Particle Size ◽

Manganese Oxide ◽

Energetic Materials ◽

Average Particle Size ◽

Active Surface ◽

Propagation Rate ◽

Hydroxyl Groups ◽

Average Particle ◽

Decomposition Enthalpy

Abstract Nanostructured energetic materials can fit with advanced energetic first-fire, and electric bridges (microchips). Manganese oxide, with active surface sites (negatively charged surface oxygen, and hydroxyl groups) can experience superior catalytic activity. Manganese oxide could boost decomposition enthalpy, ignitability, and propagation rate. Furthermore manganese oxide could induce vigorous thermite reaction with aluminium particles. Hot solid or liquid particles are desirable for first-fire compositions. This study reports on the facile fabrication of MnO2 nanoparticles of 10 nm average particle size; aluminium nanoplates of 100 nm average particle size were employed. Nitrocellulose (NC) was adopted as energetic polymeric binder. MnO2/Al particles were integrated into NC matrix via co-precipitation technique. Nanothermite particles offered an increase in NC decomposition enthalpy by 150 % using DSC; ignition temperature was decreased by 8 0C. Nanothemrite particles offered enhanced propagation index by 261 %. Kinetic study demonstrated that nanothermite particles experienced drastic decrease in NC activation energy by - 42, and - 40 KJ mol-1 using Kissinger and KAS models respectively. This study shaded the light on novel nanostructured energetic composition, with superior combustion enthalpy, propagation rate, and activation energy.

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