Applications

The main pollutants in water bodies include pharmaceuticals, surfactants, personal care products, synthetic dyes, pesticides, and industrial chemicals. These pollutants are challenging to remove and can adversely affect human health, including the nervous, developmental, and reproductive systems. Therefore, protecting water environments is of utmost importance.   In recent years, advanced oxidation processes (AOPs) such as Fenton-like reactions, persulfate activation, and UV-light-induced AOPs (e.g., UV/Cl2, UV/NH2Cl, UV/H2O2, UV/PS) as well as photocatalysts (e.g., bismuth vanadate (BiVO4), bismuth tungstate (Bi2WO6), carbon nitride (C3N4), titanium dioxide (TiO2) have gained attention in the field of water treatment and environmental remediation.   These systems can generate highly reactive species such as hydroxyl radicals (•OH), sulfate radicals (•SO4-), superoxide radicals (•O2-), singlet oxygen (1O2), etc. These techniques significantly enhance the removal rates of organic pollutants compared to conventional physical and biological methods. The development of these water treatment technologies greatly benefits from the assistance of Electron Paramagnetic Resonance (EPR) technology.   CIQTEK offers the desktop Electron Paramagnetic Resonance spectrometer EPR200M and the X-band continuous-wave Electron Paramagnetic Resonance spectrometer EPR200-Plus, which provide solutions for studying photocatalysis and advanced oxidation processes in water treatment.   Application Solutions of Electron Paramagnetic Resonance (EPR) technology in water treatment research   - Detect, identify, and quantify reactive species such as •OH, •SO4-, •O2-, 1O2, and other active species generated in photocatalytic and AOPs systems.   - Detect and quantify vacancies/defects in remediation materials, such as oxygen vacancies, nitrogen vacancies, sulfur vacancies, etc.   - Detect doped transition metals in catalytic materials.   - Verify the feasibility and assist in optimizing various parameters of water treatment processes.   - Detect and determine the proportion of reactive species during water treatment processes, providing direct evidence for pollutant degradation mechanisms.     Application Cases of Electron Paramagnetic Resonance (EPR) technology in water treatment research   Case 1: EPR in UV/ClO2-based advanced oxidation technology   - EPR study of the degradation process of fluoroquinolone antibiotics in a UV-mediated AOPs system.   - Degradation of pharmaceuticals and personal care products (PPCPs) in water by chlorine dioxide under UV conditions.   - EPR detection and qualitative analysis of •OH and singlet oxygen as active species in the system.   - Increase in •OH and 1O2 concentrations with longer irradiation times, promoting antibiotic degradation.   - EPR detection of •OH and 1O2 co...

In the fascinating world of nature, lizards are renowned for their remarkable ability to change colors. These vibrant hues not only captivate our attention but also play a crucial role in the survival and reproduction of lizards. But what scientific principles underlie these dazzling colors? This article, in conjunction with the CIQTEK Field Emission Scanning Electron Microscope (SEM) product, aims to explore the mechanism behind the color-changing ability of lizards.   Section 1: Lizard Coloration Mechanism   1.1 Categories based on formation mechanisms: Pigmented Colors and Structural Colors   In nature, animal colors can be divided into two categories based on their formation mechanisms: Pigmented Colors and Structural Colors.   Pigmented Colors are produced by changes in the concentration of pigments and the additive effect of different colors, similar to the principle of "primary colors."   Structural Colors, on the other hand, are generated by the reflection of light from finely structured physiological components, resulting in different wavelengths of reflected light. The underlying principle for structural colors is primarily based on optical principles.   1.2 Structure of Lizard Scales: Microscopic Insights from SEM Imaging   The following images (Figures 1-4) depict the characterization of iridophores in lizard skin cells using CIQTEK SEM5000Pro-Field Emission Scanning Electron Microscope. Iridophores exhibit a structural arrangement similar to diffraction gratings, and we refer to these structures as crystalline plates. The crystalline plates can reflect and scatter light of different wavelengths.   Section 2: Environmental Influence on Color Change   2.1 Camouflage: Adapting to the Surroundings   Research has revealed that changes in the size, spacing, and angle of the crystalline plates in lizard iridophores can alter the wavelength of light scattered and reflected by their skin. This observation is of significant importance for studying the mechanisms behind color change in lizard skin.   2.2 High-Resolution Imaging: Characterizing lizard skin cells   Characterizing lizard skin cells using a Scanning Electron Microscope allows for a visual examination of the structural characteristics of crystalline plates in the skin, such as their size, length, and arrangement.     Figures1. ultrastructure of lizard skin/30 kV/STEM    Figures2.  ultrastructure of lizard skin/30 kV/STEM    Figures3.  ultrastructure of lizard skin/30 kV/STEM   Figures4.  ultrastructure of lizard skin/30 kV/STEM   Section 3: Advances in Lizard Coloration Research with CIQTEK Field Emission SEM   The "Automap" software developed by CIQTEK can be used to perform large-scale macro-structural characterization of lizard skin cells, with a maximum coverage of up to a centimeter scale. Thus, ...

From rich peanut oil to fragrant olive oil, various types of edible vegetable oils not only enrich people's food culture, but also meet diversified nutritional needs. With the improvement of the national economy and residents' living standards, the consumption of edible vegetable oils continues to grow, and it is particularly important to ensure its quality and safety.   1. Use EPR Technology to Scientifically Evaluate the Quality of Edible Oil Electron paramagnetic resonance (EPR) technology, with its unique advantages (no pretreatment required, in-situ non-destructive, direct sensitivity), plays an important role in edible oil quality monitoring.   As a highly sensitive detection method, EPR can deeply explore the unpaired electron changes in the molecular structure of edible oils. These changes are often microscopic signs of the early stages of oil oxidation. The essence of oil oxidation is a free radical chain reaction. The free radicals in the oxidation process are mainly ROO·, RO· and R·.   By identifying oxidation products such as free radicals, EPR technology can scientifically evaluate the degree of oxidation and stability of edible oils before they show obvious sensory changes. This is essential to promptly detect and prevent grease deterioration caused by improper storage conditions such as light, heat, oxygen exposure or metal catalysis. Considering that unsaturated fatty acids are easily oxidized, edible oils face the risk of rapid oxidation even under normal temperature conditions, which not only affects their flavor and nutritional value, but also shortens the shelf life of the product.   Therefore, the use of EPR technology to scientifically evaluate the oxidation stability of oils can not only provide consumers with safer and fresher edible oil products, but also effectively guide the rational use of antioxidants, ensure the quality control of oil-containing foods, and extend the shelf life of market supply. . In summary, the application of electron paramagnetic resonance technology in the field of edible oil quality monitoring is not only a vivid manifestation of scientific and technological progress serving the people, but also an important line of defense for maintaining food safety and protecting public health.   2. Application cases of EPR in oil monitoring Principle: A variety of free radicals will be generated during lipid oxidation. The generated free radicals are more active and have shorter lifespans. Therefore, the spin capture method is often used for detection (the spin capture agent reacts with the active free radicals to form a more stable Free radical adducts, PBN is generally used as a spin trap).   (1) Evaluate the oxidation stability of oil (the influence of external factors such as temperature on the oxidation stability of oil can be observed)   The antioxidant capacity of a product can be determined by measuring the concentration of free r...

Use a Scanning Electron Microscope (SEM) to look at cat hair   Hair is a derivative of the stratum corneum of the skin epidermis, which is also one of the characteristics of mammals. The hair of all animals has its basic shape and structure, with many differentiated hair morphologies (such as length, thickness, color, etc.). That must be closely related to its microstructure. Therefore, the microstructure of hair has also been the focus of research for many years.   In 1837, Brewster used optical microscopy for the first time to discover the specific structure on the surface of hair, marking the beginning of the study of hair microstructure.   In the 1980s, with the widespread application of electron microscopes in the study of hair microstructure, the study of hair microstructure was further improved and developed.   Under the Scanning Electron Microscope, the image of hair structure is clearer, more precise, and has a strong three-dimensional sense, high resolution, and can be observed from different angles. Therefore, Scanning Electron Microscope has become widely used in the observation of animal hair. Microstructure of Cat Hair under Scanning Electron Microscope   Cats are a widely raised pet. Most species have soft fur, which makes people quite fond of them. So, what information can we obtain from SEM images of cat hair? With questions in mind, we collected hair from different body parts of cats and used a Tungsten Filament Scanning Electron Microscope to observe the microstructure of the hair.   According to the characteristics of hair surface structure and morphology, it can be divided into four categories: finger-like, bud-like, wavy, and squamous. The picture below shows the hair of a British shorthair cat.   As can be seen from the scanning electron microscope image, its surface has an obvious wavy structure. The same surface structural units are the hair of dogs, roe deer, cows, and donkeys. Their diameters are generally between 20 and 60 μm. The width of the wavy unit is almost transverse to the entire circumference of the hair shaft, and the axial distance between each wavy unit is about 5 μm. The diameter of the British shorthair cat hair in the picture is about 58 μm.   After zooming in, you can also see the surface hair scale structure. The width of the scales is about 5 μm, and the aspect ratio is about 12:1. The aspect ratio of the corrugated unit structure is small, and the aspect ratio is related to the flexibility of the hair. The larger the aspect ratio, the better the softness of the hair, and its stiffness is not easy to break. There is a certain gap between the hair scales and the hair shaft. A larger gap can store air, slow down the airflow speed, and reduce the heat exchange speed. Therefore, different surface unit shapes also determine the difference in thermal insulation performance. British shorthair cat hair surface /10kV/ETD British shorthair cat hair surface /10...

The lizard skin cells used in this paper were provided by the research group of Che Jing, Kunming Institute of Zoology, Chinese Academy of Sciences. 1. Background Lizards are a group of reptiles that live on the earth with different body shapes and in different environments. Lizards are highly adaptable and can survive in a wide range of environments. Some of these lizards also have colorful colors as protection or for courtship behavior. The development of lizard skin coloration is a very complex biological evolutionary phenomenon. This ability is widely found in many lizards, but how exactly does it arise? In this article, we will take you to understand the mechanism of lizard discoloration in conjunction with CIQTEK Field Emission Scanning Electron Microscope products. 2. CIQTEK Field Emission Scanning Electron Microscope As a high-end scientific instrument, the scanning electron microscope has become a necessary characterization tool in the process of scientific research with its advantages of high resolution and wide range of magnification. In addition to obtaining information about the surface of the sample, the internal structure of the material can be obtained by applying transmission mode (Scanning transmission electron microscopy (STEM)) with the scanning transmission detector accessory on the SEM. In addition, compared with traditional transmission electron microscopy, the STEM mode on the SEM can significantly reduce the damage of the electron beam on the sample due to its lower accelerating voltage and greatly improve the image lining, which is especially suitable for structural analyses of soft material samples such as polymers and biological samples. CIQTEK SEMs can be equipped with this scanning mode, among which SEM5000, as a popular CIQTEK field emission model, adopts advanced barrel design, including high-voltage tunneling technology (SuperTunnel), low aberration non-leakage objective design, and has a variety of imaging modes: INLENS, ETD, BSED, STEM, etc., and the resolution of the STEM mode is up to 0.8nm@30kv. Animal body colors in nature can be divided into two categories according to the formation mechanism: pigmented colors and structural colors. Pigmented colors are produced through changes in the content of pigment components and the superposition of colors, similar to the principle of "three primary colors"; whereas structural colors are formed by reflecting light through fine physiological structures to produce colors with different wavelengths of reflected light, which is based on the principle of optics. The following figures (Figures 1-4) show the results of using the SEM5000-STEM accessory to characterize the iridescent cells in the skin cells of lizards, which have a structure similar to a diffraction grating, which we will tentatively call a crystal sheet, and which is capable of reflecting an...

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 ...

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...