Applications

Molecular sieves are artificially synthesized hydrated aluminosilicates or natural zeolites with molecular sieving properties. They have uniformly sized pores and well-arranged channels and cavities in their structure. Molecular sieves of different pore sizes can separate molecules of different sizes and shapes. They possess functions such as adsorption, catalysis, and ion exchange, which give them tremendous potential applications in various fields such as petrochemical engineering, environmental protection, biomedical, and energy.   In 1925, the molecular separation effect of zeolite was first reported, and zeolite acquired a new name — molecular sieve. However, the small pore size of zeolite molecular sieves limited their application range, so researchers turned their attention to the development of mesoporous materials with larger pore sizes. Mesoporous materials (a class of porous materials with pore sizes ranging from 2 to 50 nm) have extremely high surface area, regularly ordered pore structures, and continuously adjustable pore sizes. Since their inception, mesoporous materials have become one of the interdisciplinary frontiers.   For molecular sieves, particle size and particle size distribution are important physical parameters that directly affect product process performance and utility, particularly in catalyst research. The crystal grain size, pore structure, and preparation conditions of molecular sieves have significant effects on catalyst performance. Therefore, exploring changes in molecular sieve crystal morphology, precise control of their shape, and regulating and enhancing catalytic performance are of great significance and have always been important aspects of molecular sieve research. Scanning electron microscopy provides important microscopic information for studying the structure-performance relationship of molecular sieves, aiding in guiding the synthesis optimization and performance control of molecular sieves.   ZSM-5 molecular sieve has an MFI structure. The product selectivity, reactivity and stability of MFI-type molecular sieve catalysts with different crystal morphologies may vary depending on the morphology.   Figure 1(a) MFI skeleton topology   The following are images of ZSM-5 molecular sieve captured using the CIQTEK High-Resolution Field Emission Scanning Electron Microscope SEM5000X.   Figure 1(b) ZSM-5 molecular sieve/500V/Inlens SBA-15 is a common silicon-based mesoporous material with a two-dimensional hexagonal pore structure, with pore sizes typically ranging from 3 to 10 nm. Most mesoporous materials are non-conductive, and the commonly used pre-treatment method of coating (with Pt or Au) may block the nanoscale pores, affecting the characterization of their microstructure.   Therefore, such samples are usually not subjected to any coating pre-treatment, which requires the scanning electron microscope to have ultra-high resolution imaging capability even at extr...

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...

Porous adsorbents play an important role in the fields of environmental purification, energy storage and catalytic conversion due to their unique porous structure and properties. Porous adsorbents usually have high specific surface area and rich pore distribution, which can effectively interact with molecules in gas or liquid. Using static gas adsorption method to accurately characterize parameters such as BET and Pore Distribution, can help to gain a deeper understanding of the properties and adsorption performance of porous adsorbents.   BET and Pore Distribution of porous adsorbents   Porous adsorbents are a type of material with high specific surface area and rich pore structure, which can capture and fix molecules in gas or liquid through physical or chemical adsorption. There are many types of them, including inorganic porous adsorbents (activated carbon, silica gel, etc.), organic Polymer adsorbents (ion exchange resins, etc.), coordination polymers (MOFs, etc.) and composite porous adsorbents, etc.   A thorough understanding of the physical properties of porous adsorbents is critical to optimizing performance and expanding application areas. The application directions of BET Surface Area & Porosimetry Analyzer in the porous adsorbent industry mainly include quality control, research and development of new materials, optimization of separation processes, etc. By accurately testing the specific surface area and pore distribution, the performance of porous adsorbents can be improved in a targeted manner to meet specific application needs and improve the selective adsorption of target molecules.   In summary, analyzing the specific surface area and pore distribution of porous adsorbents through gas adsorption characterization is beneficial to evaluate the adsorption capacity, selectivity and efficiency, and is of great significance in promoting the development of new high-efficiency adsorbents.   Characterization of gas adsorption properties of MOFs materials   Metal-organic framework materials (MOFs) have become a new type of adsorption material that has attracted much attention due to its high porosity, large specific surface area, adjustable structure and easy functionalization. Through the synergistic regulation of functional group modification and pore size adjustment, the CO2 capture and separation performance of MOFs materials can be improved to a certain extent.   UiO-66 is a widely used MOFs adsorbent, often used in gas adsorption, catalytic reactions, molecular separation and other fields. The following is a case of characterization of UiO-66 material using the CIQTEK V-3220&3210 BET Surface Area & Porosimetry Analyzer.   As shown on the left side of Figure 1, the specific surface area of UiO-66 is 1253.41 m2/g. A high specific surface area can provide more active sites, which is beneficial to improving its adsorption performance. It can be seen from t...

FIB-SEM can be used for defect diagnosis, repair, ion implantation, in-situ processing, mask repair, etching, integrated circuit design modification, chip device production, and mask-less processing of large-scale integrated circuits. Nanostructure production, complex nanopattern processing, three-dimensional imaging and analysis of materials, ultra-sensitive surface analysis, surface modification, and transmission electron microscopy sample preparation, etc. It has a wide range of application requirements and is indispensable.   CIQTEK DB500 is a Field Emission Scanning Electron Microscope (FE-SEM) with a Focused Ion Beam (FIB) column for nano analysis and specimen preparation, which is applied with “SuperTunnel” electron optics technology, low aberration, and magnetic-free objective lens design, with low-voltage and high-resolution ability that ensures its nano-scale analytical capability. The ion column facilitates a Ga+ liquid metal ion source with a highly stable and high-quality ion beam to ensure nano-fabrication capability.   DB500 has an integrated nano-manipulator, gas injection system, electrical anti-contamination mechanism for the objective lens, and 24 expansion ports, making it an all-around nano-analysis and fabrication platform with comprehensive configurations and expandability.   In order to demonstrate the outstanding performance of DB500 to users, the Electron Microscopy team has specially planned the special program " CIQTEK FIB Show", which will present the wide range of applications in the fields of materials science, semiconductor industry, biomedicine, etc. in the form of video. The audience will understand the working principle of DB500, appreciate the stunning microscopic images it captures, and deeply explore the significance of this technology to scientific research and industrial development.   TEM sample preparation In this episode, we will show you how DB500 can prepare transmission electron microscope (TEM) samples efficiently and accurately.   As you can see from the video, DB500 prepares TEM samples with simple operation, few pre-processing steps, low learning costs, and efficient testing; it can achieve precise micro- and nanoscale cutting at fixed points, with controllable size and uniform thickness, and is suitable for a variety of microscopy and Microscopic spectroscopy analysis; and the integration of cutting, imaging, and analysis can be achieved.

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...

Scanning electron microscope as a commonly used microscopic analysis tools, can be observed on all types of metal fracture, fracture type determination, morphology analysis, failure analysis and other research.   What is a metal fracture?   When a metal is broken by an external force, two matching sections are left at the fracture site, which is called a "fracture". The shape and appearance of this fracture contains a lot of important information about the fracture process.   By observing and studying the morphology of the fracture, we can analyze the cause, nature, mode, mechanism, etc., and also understand the details of the stress condition and crack expansion rate at the time of fracture. Like a "scene", the fracture retains the whole process of fracture occurrence. Therefore, for the study of metal fracture problems, observation and analysis of fracture is a very important step and means. Scanning electron microscope has the advantages of large depth of field and high resolution, and has been widely used in the field of fracture analysis.   Application of Scanning Electron Microscope in Metal Fracture Analysis   There are various forms of failure of metal fracture. Categorized by the degree of deformation before fracture, they can be divided into brittle fracture, ductile fracture, and mixed brittle and ductile fracture. Different fracture forms will have characteristic microscopic morphology, which can be characterized by SEM to help researchers to quickly perform fracture analysis.   Ductile Fracture   Ductile fracture is a fracture that occurs after a large amount of deformation of a member, which is mainly characterized by significant macroplastic deformation. The macroscopic morphology is a cup-and-cone fracture or a pure shear fracture, and the fracture surface is fibrous and consists of tough nests. As shown in Figure 1, microscopically its fracture is characterized by: the fracture surface consists of a number of tiny wineglass-shaped microporous pits, usually referred to as tough fossa. Toughness fossa is the trace left on the fracture surface after plastic deformation of the material in the range of micro-region generated by the micro-void, through the nucleation/growth/aggregation, and finally interconnected to lead to fracture.     Fig. 1 Metal ductile fracture fracture/10kV/Inlens   Brittle Fracture   Brittle fracture is the fracture of a member without significant deformation. There is little plastic deformation of the material at the time of fracture. While macroscopically it is crystalline, microscopically it includes fracture along the crystal, disintegration fracture or quasi-disintegration fracture. As shown in Fig. 2, a mixed brittle-ductile fracture fracture of the metal, in the ductile fracture region, a distinctive toughness nest feature can be observed. In the brittle fracture region, it belongs to along-crystalline brittle fracture, which refers to the fract...

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.