Applications

5A molecular sieve is a kind of calcium-type aluminosilicate with cubic lattice structure, also known as CaA-type zeolite. 5A molecular sieve has developed pore structure and excellent selective adsorption, which is widely used in the separation of n-isomerized alkanes, the separation of oxygen and nitrogen, as well as natural gas, ammonia decomposition gas, and the drying of other industrial gases and liquids. 5A molecular sieve has an effective pore size of 0.5 nm, and the determination of the pore distribution is generally characterized by gas adsorption using a physical adsorption instrument. The effective pore size of 5A molecular sieve is about 0.5 nm, and its pore size distribution is generally characterized by gas adsorption using physical adsorption instrument. The specific surface and pore size distribution of 5A molecular sieves were characterized by CIQTEK EASY-V series specific surface and pore size analyzers. Before testing, the samples were degassed by heating under vacuum at 300℃ for 6 hours. As shown in Fig. 1, the specific surface area of the sample was calculated as 776.53 m2/g by the multi-point BET equation, and then the microporous area of the sample was obtained as 672.04 m2/g, the external surface area as 104.49 m2/g, and the volume of the microporous as 0.254 cm3/g by t-plot method, which showed that the microporous area of this molecular sieve accounted for about 86.5%. In addition, the analysis of the N2 adsorption-desorption isotherm plot of this 5A molecular sieve (Fig. 2, left) reveals that the adsorption isotherm shows that the adsorption amount increases sharply with the increase of the relative pressure when the relative pressure is small, and the filling of micropores occurs, and the curve is relatively flat after reaching a certain value, which suggests that the sample is rich in micropores. The microporous pore size distribution calculation using the SF model (Fig. 2, right panel) yielded a concentrated microporous pore size distribution at 0.48 nm, which is consistent with the pore size of 5A molecular sieves.   Fig. 1 Specific surface area test results (left) and t-Plot results (right) of 5A molecular sieve   Fig. 2 N2-sorption and desorption isotherms (left) and SF-pore size distribution plots (right) of 5A molecular sieve samples      CIQTEK Automatic BET Surface Area & Porosimetry Analyzer | EASY-V 3440 EASY-V 3440 is the BET specific surface area and pore size analysis instrument developed independently by CIQTEK, using the static volumetric method.   ▪  Specific surface area testing, range 0.0005 (m2/g) and above. ▪  Pore size analysis: 0.35 nm-2 nm (micropore), micropore size distribution analysis; 2 nm-500 nm (mesopore or macropore). ▪  Four analysis stations, simultaneous testing of 4 samples. ▪  Equipped with the molecular pump.

Zeolite imidazolium skeleton (ZIFs) materials as a subclass of metal-organic skeletons (MOFs), ZIFs materials combine the high stability of inorganic zeolites and the high specific surface area, high porosity and tunable pore size of MOFs materials, which can be applied to efficient catalytic and separation processes, so ZIFs and their derivatives have good potential for use in catalysis, adsorption and separation, electrochemistry, biosensor and biomedicine and other fields with good application prospects. The following is a case study of the characterization of ZIF molecular sieves using CIQTEK EASY-V series specific surface and pore size analyzer. As shown in Fig. 3 left, the specific surface area of this ZIF molecular sieve is 857.63 m2/g. The material has a large specific surface area which is favorable for the diffusion of reactive substances. From the N2-adsorption and desorption isotherms (Fig. 3, right), it can be seen that there is a sharp increase in adsorption in the low partial pressure region (P/P0 < 0.1), which is attributed to the filling of micropores, indicating that there is a certain amount of microporous structure in the material, and there is a hysteresis loop within the range of P/P0 of about 0.40 to 0.99, which suggests that there is an abundance of mesoporous structure in this ZIF molecular sieve. The SF-pore size distribution graph (Fig. 4, left) shows that the most available pore size of this sample is 0.56 nm. The total pore volume of this ZIF molecular sieve is 0.97 cm3/g, and the microporous volume is 0.64 cm3/g, with 66% of micropores, and the microporous structure can significantly increase the specific surface area of the sample, but the molecular sieve will limit the catalytic activity under certain conditions due to the smaller pore size. However, under certain conditions, the smaller pore size will limit the diffusion rate of the catalytic reaction, which makes the performance of molecular sieve catalyst limited, however, the mesoporous structure can obviously make up for this defect of the microporous structure, so the structure of the combination of microporous-mesoporous can effectively solve the problem of the limitation of the mass transfer capacity of the traditional molecular sieve with a single pore.   Fig. 1 Specific surface area test results (left) and N2-sorption and desorption isotherms (right) for ZIF molecular sieves Fig. 2 SF-pore size distribution (left) and NLDFT-pore size distribution (right) of ZIF molecular sieve

The characterization of copper foil morphology by scanning electron microscopy can help researchers and developers to optimize and improve the preparation process and performance of copper foils to further meet the existing and future quality requirements of high-performance lithium-ion batteries. Wide Range of Copper Applications Copper metal is widely used in lithium-ion batteries and printed circuit boards because of its ductility, high conductivity, ease of processing and low price. Depending on the production process, copper foil can be categorized into calendered copper foil and electrolytic copper foil. Calendered copper foil is made of copper blocks rolled repeatedly, with high purity, low roughness and high mechanical properties, but at a higher cost. Electrolytic copper foil, on the other hand, has the advantage of low cost and is the mainstream copper foil product in the market at present. The specific process of electrolytic copper foil is (1) dissolving copper: dissolve raw copper to form sulfuric acid-copper sulfate electrolyte, and remove impurities through multiple filtration to improve the purity of the electrolyte. (2) Raw foil preparation: usually polished pure titanium rolls as the cathode, through electrodeposition of copper ions in the electrolyte is reduced to the surface of the cathode to form a certain thickness of copper layer. (3) Surface treatment: the raw foil is peeled off from the cathode roll, and then after post-treatment, the finished electrolytic copper foil can be obtained. Figure 1 Electrolytic Copper Foil Production Process Copper Metal in Lithium-ion Batteries Lithium-ion batteries are mainly composed of active materials (cathode material, anode material), diaphragm, electrolyte and conductive collector. Positive potential is high, copper is easy to be oxidized at higher potentials, so copper foil is often used as the anode collector of lithium-ion batteries. The tensile strength, elongation and other properties of copper foil directly affect the performance of lithium-ion batteries. At present, lithium-ion batteries are mainly developed towards the trend of "light and thin", so the performance of electrolytic copper foil also puts forward higher requirements such as ultra-thin, high tensile strength and high elongation. How to effectively improve the electrolytic copper foil process to enhance the mechanical properties of copper foil is the main research direction of copper foil in the future. Suitable additive formulation in the foil making process is the most effective means to regulate the performance of electrolytic copper foil, and qualitative and quantitative research on the effect of additives on the surface morphology and physical properties of electrolytic copper foil has been a research hotspot for scholars at home and abroad. In materials science, the microstructure determines its mechanical properties, and the use of scanning electron microscopy to characterize the changes in the surface micro-m...

Environmental pollution is one of the global crises and is affecting the quality of living and health of the entire population. A new class of harmful substances, the environmentally persistent free radicals (EPFRs). These pollutants are pervasive and can be found in air, water, and soil. The EPFRs can be recognized as biohazard since it can produce reactive oxide species (ROS), which causes cell and tissue damages and ultimately cancer. To mitigate and eventually find a solution to this problem, tracing the origin of such pollutants is needed. Electron paramagnetic resonance (EPR) spectroscopy is a powerful tool and can be used for such tasks.   What are EPFRs   The conventionally recognized free radicals are often transient with a short lifetime. On the contrary, EPFRs can be stable in the environment for tens of minutes to tens of days without being oxidized or quenched. The commonly found EPFRs include, cyclopentadienyl, semiquinone, phenoxy, and other radicals.     Common EPFRs     Where do EPFRs come from?   EPFRs are found in a wide range of environmental media, such as atmospheric particulate matter (e.g. PM 2.5), factory emissions, tobacco, petroleum coke, wood and plastic, coal combustion particulates, soluble fractions in water bodies, and organically contaminated soils, etc. EPFRs have a wide range of transport pathways in environmental media and can be transported through vertical ascent, horizontal transport, vertical deposition to water bodies, vertical deposition to land, and landward migration of water bodies. In the process of migration, new reactive radicals may be generated, which directly affects the environment and are precursors to other pollutants.   Formation and Multimediated Transfer of EPFRs (Environmental Pollution 248 (2019) 320-331)     Application of EPR Technique for the Detection of EPFRs   EPR spectroscopy is extremely sensitive to unpaired electrons, and a directly measurement of signals from these radicals make it an ideal method for monitoring the presence of EPFRs in different samples.  . For the detection of EPFRs, EPR (ESR) spectroscopy provides information in both spatial and temporal dimensions. By measuring and analyzing the continuous-wave EPR spectra of samples, the researchers are able to not only verifying the presence of radicals but also obtain g-values and hyperfine coupling constants of electrons, which can be used for inferring electronic structure of measured molecules. The temporal resolution refers to the half-life of EPFRs, which can also be obtained from monitoring their EPR signals over time.     Application of EPR Technology in Detecting EPFRs in the Soil Environment   Petroleum processing, storage, transportation, and possible leakage from storage tanks are all susceptible to soil contamination. Although thermal treatment techniques can be used to remediate soils contaminated by various volatile, semi-volati...

The name coral comes from the Old Persian sanga (stone), which is the common name for the coral worm community and their skeleton. Coral polyps are corals of the phylum Acanthozoa, with cylindrical bodies, which are also called living rocks because of their porosity and branching growth, which can be inhabited by many microorganisms and fish. Corals flourish in tropical ocean. The chemical composition of white coral is mainly CaCO3 and contains organic matter, called carbonate type. Golden, blue, and black coral is composed of keratin, called keratin type. Red coral (including pink, flesh red, rose red, light red to deep red) shell has more keratin and CaCO3. Cora, based on  the skeletal structure characteristics, can be divided into plate bed coral, four-shot coral, six-shot coral, and eight-shot coral. Modern coral is mostly the latter two categories. Coral is an important carrier to record the marine environment, for the determination of paleoclimatology, ancient sea level change and tectonic movement and other studies have important significance.   Electron paramagnetic resonance spectroscopy is a powerful tool for studying substances with unpaired electrons. This technique utilizes microwave irradiation to probe the energy separation of unpaired electrons created by an external magnetic field.  A special application of EPR spectroscopy is developed for analyzing corals, which is a valuable method marine environmental studies.   The information regarding paleoclimate is reflected in the Mn2+ concentration in coral reef. Using EPR spectroscopy, the signal of Mn2+ can be easily analyzed and interpreted, since its concentration is relatively high during a warm period and decreases sharply during a period of rapid cooling. Another set of substances in coral that can be measured by EPR spectroscopy is lattice defects and impurities produced by natural irradiation. Such lattice defects trap unpaired electrons, which produces observable EPR signals. The lineshape of such signals are indicative to the composition of minerals and trapped impurities, and therefore can be used for inferring the information about age of formation as well as crystallization condition of samples.   The EPR signal in the coral will be analyzed using a CIQTEK X-Band EPR (ESR) spectroscopy EPR100 to provide information on the composition and defect vacancies in the coral.   CIQTEK X-Band EPR100   Experimental Sample The sample was taken from white coral in the South China Sea, treated with 0.1 mol/L dilute hydrochloric acid, crushed with a mortar, sieved, dried at 60°C, weighed about 70 mg, and tested on the CIQTEK EPR100.   White Coral Sample   Electron Paramagnetic Resonance Spectroscopy The CIQTEK EPR100 was used to test the EPR signal in white coral. To achieve accurate measurement of the EPR signal, the specific experimental conditions were as follows.   Experimental Conditions ...

Conductive paste is a special functional material with both conductive and bonding properties, widely used in new energy batteries, photovoltaic, electronics, chemical industry, printing, military and aviation and other fields. Conductive paste mainly includes conductive phase, bonding phase and organic carrier, of which the conductive phase is the key material of conductive paste, determining the electrical properties of the paste and the mechanical properties after film formation.   The commonly used materials of conductive phase include metal, metal oxide, carbon materials and conductive polymer materials, etc. It is found that the physical parameters such as specific surface area, pore size and true density of conductive phase materials have an important influence on the conductivity and mechanical properties of the slurry. Therefore, it is particularly important to accurately characterise physical parameters such as specific surface area, pore size distribution and true density of conductive phase materials based on gas adsorption technology. In addition, precise tuning of these parameters can optimise the conductivity of the pastes to meet the requirements of different applications.   01 Conductive paste introduction According to the actual application of different types of conductive paste is not the same, usually according to the different types of conductive phase, can be divided into conductive paste: inorganic conductive paste, organic conductive paste and composite conductive paste. Inorganic conductive paste is divided into metal powder and non-metallic two kinds of metal powder mainly gold, silver, copper, tin and aluminium, etc., non-metallic conductive phase is mainly carbon materials. Organic conductive paste in the conductive phase is mainly conductive polymer materials, which has a smaller density, higher corrosion resistance, better film-forming properties and in a certain range of conductivity adjustable and so on. Composite system conductive paste is currently an important direction of conductive paste research, the purpose is to combine the advantages of inorganic and organic conductive paste, the inorganic conductive phase and organic material support body organic combination, give full play to the advantages of both.   Conductive phase as the main functional phase in the conductive paste, to provide electrical pathway, to achieve electrical properties, its specific surface area, pore size and true density and other physical parameters have a greater impact on its conductive properties.   Specific surface area: the size of the specific surface area is the key factor affecting the conductivity, within a certain range, a larger specific surface area provides more electronic conduction pathways, reducing the resistance, making the conductive paste more conductive. High conductivity is critical in many applications, such as in electronic devices to ensure efficient conduction of circuits.   Pore size: ...

To begin with, what is aged rice and new rice? Aged rice or old rice is nothing but stocked rice that is kept for aging for one or more years. On the other hand, new rice is the one which is produced from newly harvested crops. Compared to the fresh aroma of new rice, aged rice is light and tasteless, which is essentially a change in the internal microscopic morphological structure of aged rice. Researchers analyzed new rice and aged rice using the CIQTEK tungsten filament scanning electron microscope SEM3100. Let's see how they differ in the microscopic world!   CIQTEK Tungsten Filament Scanning Electron Microscope SEM3100   Figure 1 Cross-sectional fracture morphology of new rice and aged rice   First, the microstructure of rice endosperm was observed by SEM3100. From Figure 1, it can be seen that the endosperm cells of new rice were long polygonal prismatic cells with starch grains wrapped in them, and the endosperm cells were arranged in a radial fan shape with the center of the endosperm as concentric circles, and the endosperm cells in the center were smaller compared with the outer cells. The radial fan-shaped endosperm structure of new rice was more obvious than that of aged rice.   Figure 2 Microstructure morphology of the central endosperm of new rice and aged rice   Further magnified observation of the central endosperm tissue of rice revealed that the endosperm cells in the central part of aged rice were more broken and the starch granules were more exposed, making the endosperm cells radially arranged in a blurred form.   Figure 3 Microstructure morphology of protein film on the surface of new rice and aged rice   The protein film on the surface of the endosperm cells was observed at high magnification using the advantages of SEM3100 with high-resolution imaging. As can be seen from Figure 3, a protein film could be observed on the surface of new rice, while the protein film on the surface of aged rice was broken and had different degrees of warping, resulting in relatively clear exposure of the internal starch granule shape due to the reduction of the surface protein film thickness.    Figure 4 Microstructure of endosperm starch granules of new rice   Rice endosperm cells contain single and compound amyloplasts. Single-grain amyloplasts are crystalline polyhedra, often in the form of single grains with blunt angles and obvious gaps with the surrounding amyloplasts, containing mainly crystalline and amorphous regions formed by straight-chain and branched-chain amylose [1,2]. The complex grain amyloplasts are angular in shape, densely arranged, and tightly bound to the surrounding amyloplasts. Studies have shown that the starch grains of high-quality rice exist mainly as complex grains [3]. By observing the endosperm cells of new rice, as shown in Figure 4, the starch grains mostly existed in the form of compound grains. The compound starch grains were angular in shape and closely...

Have you ever noticed that commonly used pills or vitamin tablets have a thin coating on their surface? This is an additive made from magnesium stearate, which is usually added to medicines as a lubricant. So why is this substance added to medicines?     What is Magnesium Stearate?   Magnesium Stearate is a widely used pharmaceutical excipient. It is a mixture of magnesium stearate (C36H70MgO4) and magnesium palmitate (C32H62MgO4) as the main ingredients, which is a fine white non-sanding powder with a slippery sensation when in contact with the skin. Magnesium stearate is one of the most commonly used lubricants in pharmaceutical production, with good anti-adhesive, flow-increasing, and lubricating properties. The addition of magnesium stearate in the production of pharmaceutical tablets can effectively reduce the friction between the tablets and the die of the tablet press, greatly reducing the tablet force of the pharmaceutical tablet press and improving the consistency and quality control of the drug.     Magnesium Stearate Image from the Internet   The key property of magnesium stearate as a lubricant is its specific surface area, the larger the specific surface area, the more polar it is, the greater the adhesion, and the easier it is to distribute evenly on the particle surface during the mixing process, the better the lubricity. CIQTEK self-developed static volume method-specific surface and pore size analyzer V-Sorb X800 series can be used to test the gas adsorption of magnesium stearate and other materials, and analyze the material's BET surface area. The instrument is easy to operate, accurate, and highly automated.   Effect of Specific Surface Area on Magnesium Stearate Studies have pointed out that the physical properties of the lubricant can also have a significant impact on the pharmaceutical product, such as the lubricant surface condition, particle size, size of surface area, and structure of the crystals. Through grinding, drying, and storage magnesium stearate can change its original physical properties, thus affecting its lubricating function.   Good magnesium stearate has a low shear lamellar structure [1] and can be properly mixed with the active component of the drug and other excipients to provide lubrication between the compacted powder and the mould wall and to prevent adhesion between the powder and the mould. The larger the specific surface area of magnesium stearate, the easier it is to distribute it evenly over the surface of the particles during the mixing process, and the better the lubrication. Under certain conditions of the mixture and the tablet press, the larger the specific surface area of magnesium stearate the lower the tensile strength of the tablets obtained, the higher the brittleness, and the slower the dissolution and disintegration. Therefore, the surface area is considered an important technical index of pharmaceutical-grade magnesium stearate. The specific sur...