Applications

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...

Ceramic materials have a series of characteristics such as high melting point, high hardness, high wear resistance, and oxidation resistance, and are widely used in various fields of national economy such as the electronics industry, automotive industry, textile, chemical industry, and aerospace. The physical properties of ceramic materials depend largely on their microstructure, which is an important application area of SEM.     What are ceramics? Ceramic materials are a class of inorganic non-metallic materials made of natural or synthetic compounds through forming and high-temperature sintering and can be divided into general ceramic materials and special ceramic materials.   Special ceramic materials can be classified according to chemical composition: oxide ceramics, nitride ceramics, carbide ceramics, boride ceramics, silicide ceramics, etc.; according to their characteristics and applications can be divided into structural ceramics and functional ceramics.   Figure 1 Microscopic morphology of boron nitride ceramics   SEM helps to study the properties of ceramic materials   With the continuous development of society and science and technology, people's requirements for materials have been increasing, which requires a deeper understanding of the various physical and chemical properties of ceramics. The physical properties of ceramic materials are largely dependent on their microstructure [1], and SEM images are widely used in ceramic materials and other research fields because of their high resolution, wide adjustable magnification range, and stereoscopic imaging. The CIQTEK Field Emission Scanning Electron Microscope SEM5000 can be used to observe the microstructure of ceramic materials and related products easily, and in addition, the X-ray energy spectrometer can be used to determine the elemental composition of materials quickly.    Application of SEM in the Study of Electronic CeramicsThe largest end-use market of the special ceramics industry is the electronics industry, where barium titanate (BaTiO3) is widely used in multilayer ceramic capacitors (MLCC), thermistors (PTC), and other electronic components because of its high dielectric constant, excellent ferroelectric and piezoelectric properties, and voltage resistance and insulation properties [2]. With the rapid development of the electronic information industry, the demand for barium titanate is increasing, and the electronic components are becoming smaller and more miniaturized, which also puts forward higher requirements for barium titanate.Researchers often regulate the properties by changing the sintering temperature, atmosphere, doping, and other preparation processes. Still, the essence is that the changes in the preparation process cause changes in the microstructure of the material and thus the properties. Studies have shown that the dielectric ferroelectric properties of barium titanate are closely related to the material's mi...

Metallic materials are materials with properties such as luster, ductility, easy conductivity, and heat transfer. They are generally classified into two types: ferrous and nonferrous metals. Ferrous metals include iron, chromium, manganese, etc. [1]. Among them, steel is the basic structural material and is called the "skeleton of industry". So far, steel still dominates the composition of industrial raw materials. Many steel companies and research institutes use the unique advantages of SEM to solve production problems and assist in the development of new products. SEM with corresponding accessories has become a favorite tool for the steel and metallurgical industry to conduct research and identify problems in the production process. With the increase in SEM resolution and automation, the application of SEM in material analysis and characterization is becoming more and more widespread [2].     Failure analysis is a new discipline that has been popularized by military enterprises to research scholars and enterprises in recent years [3]. Failure of metal parts can lead to degradation of workpiece performance in minor cases and even life safety accidents in major cases. Locating the causes of failure through failure analysis and proposing effective improvement measures is an essential step for ensuring the safe operation of the project. Therefore, making full use of the advantages of scanning electron microscopy will make a great contribution to the progress of the metallic materials industry.   01 SEM Observation of the Tensile Fracture of Metals   Fracture always occurs at the weakest point in the metal tissue and records much valuable information about the whole process of fracture. Therefore, the observation and study of fracture have been emphasized in the study of fracture. The morphological analysis of the fracture is used to study some basic problems that lead to the fracture of the material, such as the cause of fracture, the nature of the fracture, and the mode of fracture. If the fracture mechanism of the material is to be studied in depth, the composition of macro-areas on the fracture surface is usually analyzed. Fracture analysis has now become an important tool for failure analysis of metallic components.   Figure 1. CIQTEK SEM3100 Tensile Fracture Morphology   According to the nature of the fracture, the fracture can be roughly divided into brittle fracture and ductile fracture. The fracture surface of a brittle fracture is usually perpendicular to the tensile stress, and from the macroscopic point of view, the brittle fracture consists of a glossy crystalline bright surface; while the ductile fracture usually has a tiny bump on the fracture and is fibrous.   The experimental basis of fracture analysis is the direct observation and analysis of the fracture surface's macroscopic morphology and microstructural characteristics. In many cases, the nature of the fracture, the locatio...

In scientific research, pollen has a wide range of applications. According to Dr. Limi Mao, Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, by extracting and analyzing different pollen deposited in the soil, it is possible to understand which parent plants they came from respectively, and thus infer the environment and climate at that time. In the field of botanical research, pollen mainly provides microscopic reference evidence for systematic taxonomy. More interestingly, pollen evidence can also be applied in criminal investigation cases. Forensic palynology can effectively corroborate the facts of a crime by using pollen spectrum evidence on the suspect's accompanying clothing and at the crime scene. In the field of geological research, pollen has been widely used in reconstructing vegetation history, past ecology, and climate change studies. In archaeological studies exploring early human farming civilizations and habitats, pollen can help scientists understand the history of early human domestication of plants, what food crops were cultivated, etc.    Fig. 1 3D pollen model picture (taken by Dr. Limi Mao, product developed by Dr. Oliver Wilson)   The size of pollen varies from a few microns to more than two hundred microns, which is beyond the resolution of visual observation and requires the use of a microscope for observation and study. Pollen comes in a wide variety of morphologies, including variations in size, shape, wall structure, and ornamentation. The ornamentation of pollen is one of the key bases for identifying and distinguishing pollen. However, the resolution of the optical biological microscope has physical limitations, it is difficult to precisely observe the differences between different pollen ornamentation, and even the ornamentation of some small pollen cannot be observed. Therefore, scientists need to use a scanning electron microscope (SEM) with high resolution and large depth of field to obtain a clear picture of pollen morphological features. In the study of fossil pollen, it is possible to identify the specific plants to which the pollen belongs, so as to more accurately understand the vegetation, environment, and climate information of the time.     The Microstructure of Pollen   Recently, researchers have used the CIQTEK Tungsten Filament SEM3100 and the CIQTEK Field Emission SEM5000 to microscopically observe a variety of pollen.  Fig. 2 CIQTEK Tungsten Filament SEM3100 and Field Emission SEM5000   1. Cherry blossom Pollen grains spherical-oblong. With three pore grooves (without treated pollen, the pores are not obvious), the grooves reach both poles. Outer wall with striate ornamentation.     2. Chinese violet cress (Orychophragmus violaceus) Chinese violet cress pollen morphology is ellipsoidal, with 3 grooves, the surface has a reticulated pattern, and the mesh size varies.     3. Ottelia Pollen grains are rounded, wit...

Expandable microspheres, small thermoplastic spheres encapsulated with gas, consist of a thermoplastic polymer shell and an encapsulated liquid alkane gas. When the microspheres are heated, the shell softens and the internal air pressure increases dramatically, causing the microspheres to expand dramatically to 60 times their original volume, giving them the dual function of a lightweight filler and a blowing agent. As a lightweight filler, expandable microspheres can greatly reduce the weight of products with very low density, and their density measurement is very important.   Figure 1 Expandable microspheres    Principle of EASY-G 1330 series true density tester EASY-G 1330 series true density tester is based on Archimedes' principle, using small molecular diameter gas as the probe and the ideal gas equation of state PV=nRT to calculate the volume of gas discharged from the material under certain temperature and pressure conditions, so as to determine the true density of the material. The small molecular diameter gas can be used as nitrogen or helium, because helium has the smallest molecular diameter and is a stable inert gas, which is not easy to react with the sample by adsorption, so helium is generally recommended as the replacement gas.    Advantages of EASY-G 1330 series true density tester EASY-G 1330 series true density tester uses gas as the probe, which will not damage the test sample, and the sample can be recycled directly; and in the testing process, the gas will not react with the sample, and will not cause corrosion to the equipment, so the safety factor of the use process is high; furthermore, the gas has the characteristics of easy diffusion, good permeability and good stability, which can penetrate into the internal pores of the material more quickly and make the test results more accurate.   Experimental Procedure   ①Warm-up: Open the cylinder main valve and pressure-reducing table, turn on the power switch at least half an hour in advance, gas pressure-reducing table output pressure: 0.4 ± 0.02 MPa;   ②Instrument Calibration: Before the experiment starts, calibrate the instrument with standard steel balls to ensure that the volume of steel balls tested in all pipelines of the equipment are within the standard value before starting the experiment;   ③Sample Tube Volume Determination: Install the empty sample tube into the instrument cavity and tighten it, set up the software, determine the sample tube volume, and record the corresponding sample tube volume at the end of the experiment;   ④Sample Weighing: In order to reduce the testing error, it is necessary to weigh as many samples as possible, each test shall weigh the sample to about 3/4 of the sample tube volume, weigh the empty tube mass M1, add the sample and weigh M2 to calculate the sample mass;   ⑤Sample Processing: All samples were not pretreated in order to achieve consistency w...

Recently, global oil prices have risen sharply and the renewable energy industry represented by solar photovoltaic (PV) power generation has received widespread attention. As the core component of PV power generation, the development prospects and market values of solar PV cells are the focus of attention. In the global battery market, PV cells account for about 27%[1]. The scanning electron microscope plays a great role in enhancing the production process and related research of PV cells.     PV cell is a thin sheet of optoelectronic semiconductor that converts solar energy directly into electrical energy. The current commercial mass-produced PV cells are mainly silicon cells, which are divided into monocrystalline silicon cells, polycrystalline silicon cells and amorphous silicon cells.     Surface Texturing Methods for Solar Cell Efficiency Enhancement   In the actual production process of photovoltaic cells, in order to further improve the energy conversion efficiency, a special textured structure is usually made on the surface of the cell, and such cells are called "non-reflective" cells. Specifically, the textured structure on the surface of these solar cells improves the absorption of light by increasing the number of reflections of irradiated light on the surface of the silicon wafer, which not only reduces the reflectivity of the surface, but also creates light traps inside the cell, thus significantly increasing the conversion efficiency of solar cells, which is important for improving the efficiency and reducing the cost of existing silicon PV cells[2].     Comparison of Flat Surface and Pyramid Structure Surface Compared to a flat surface, a silicon wafer with a pyramidal structure has a higher probability that the reflected light from the incident light will act again on the surface of the wafer rather than reflecting directly back into the air, thus increasing the number of light scattered and reflected on the surface of the structure, allowing more photons to be absorbed and providing more electron-hole pairs.    Light Paths for Different Incident Angles of Light Striking the Pyramidal Structure   The commonly used methods for surface texturing include chemical etching, reactive ion etching, photolithography, and mechanical grooving. Among them, the chemical etching method is widely used in the industry because of its low cost, high productivity, and simple method[3]. For monocrystalline silicon PV  cells, the anisotropic etching produced by alkaline solution on different crystal layers of crystalline silicon is usually used to form a structure similar to the "pyramid" formation is the result of anisotropy of alkaline solution on different crystal layers of crystalline silicon. The formation of the pyramid structure is caused by the anisotropic reaction of alkali with silicon[4]. In a certain concentration of alkali solution, the reaction rate of OH- with the surface of Si...

Drug powder is the main body of most drug formulations, and its efficacy depends not only on the type of drug, but also to a large extent on the properties of the powder that makes up the agent, including particle size, shape, surface properties and other kinds of parameters. The specific surface area and pore size structure of drug powders are related to the properties of powder particles such as particle size, hygroscopicity, solubility, dissolution and compaction, which play an important role in the purification, processing, mixing, production and packaging capabilities of pharmaceuticals.   In addition, the validity, dissolution rate, bioavailability and efficacy of drugs also depend on the specific surface area of the material. Generally speaking, the larger the specific surface area of pharmaceutical powders within a certain range, the faster the dissolution and dissolution rate will be correspondingly accelerated, which ensures the uniform distribution of drug content; however, too large a specific surface area will lead to the adsorption of more water, which is not conducive to the preservation and stability of drug efficacy. Therefore, accurate, rapid and effective testing of the specific surface area of pharmaceutical powders has always been an indispensable and critical part of pharmaceutical research.   Case Study of CIQTEK Application in Pharmaceutical Powder   We combines the actual characterization cases of different drug powder materials to clearly show the methods and applicability of this technology to characterize the physical properties of different drug surfaces, and then make some basic analysis on the expiration date, dissolution rate and efficacy of drugs, and help the pharmaceutical industry to develop with high quality.    The V-Sorb X800 series specific surface and pore size analyzer is a high throughput, fast and economical instrument, which can realize rapid testing of specific surface area of incoming and outgoing finished products, pore size distribution analysis, quality control, adjustment of process parameters, and prediction of drug performance, etc.   Automatic BET Surface Area & Porosimetry Analyzer CIQTEK EASY-V Series     CIQTEK SEMs   1、Scanning electron microscope and specific surface and pore size analyzer in montmorillonite dispersion   Montmorillonite is obtained from the purification and processing of bentonite, which has unique advantages in pharmacology because of its special crystal structure with good adsorption capacity, cation exchange capacity and water absorption and swelling capacity. For example: as API, drug synthesis, pharmaceutical excipients, etc.   Montmorillonite has a laminar structure and a large specific surface area, which can have a strong adsorption effect on toxic substances; it is electrostatically combined with digestive tract mucus proteins and plays a protective and repairing role on the digestive tract mucosa.  ...

Metallic materials are materials with properties such as luster, ductility, easy conductivity, and heat transfer. It is generally divided into two types: ferrous metals and non-ferrous metals. Ferrous metals include iron, chromium, manganese, etc. So far, iron and steel still dominate in the composition of industrial raw materials. Many steel companies and research institutes use the unique advantages of SEM to solve problems encountered in production and to assist in research and development of new products. Scanning electron microscopy with corresponding accessories has become a favorable tool for the steel and metallurgical industry to conduct research and identify problems in the production process. With the increase of SEM resolution and automation, the application of SEM in material analysis and characterization is becoming more and more widespread.   Failure analysis is a new discipline that has been popularized by military enterprises to research scholars and enterprises in recent years. Failure of metal parts can lead to degradation of workpiece performance in minor cases and life safety accidents in major cases. Locating the causes of failure through failure analysis and proposing effective improvement measures are essential steps to ensure safe operation of the project. Therefore, making full use of the advantages of scanning electron microscopy will make a great contribution to the progress of the metal material industry.     01 Electron microscope observation of tensile fracture of metal parts        Fracture always occurs in the weakest part of the metal tissue and records much valuable information about the whole process of fracture, so the observation and study of fracture has always been emphasized in the study of fracture. The morphological analysis of the fracture is used to study some basic problems that lead to the fracture of the material, such as the cause of fracture, the nature of fracture, and the mode of fracture. If we want to study the fracture mechanism of the material in depth, we usually have to analyze the composition of the micro-area on the surface of the fracture, and fracture analysis has now become an important tool for failure analysis of metal components.     Fig. 1 CIQTEK Scanning Electron Microscope SEM3100 tensile fracture morphology   According to the nature of fracture, the fracture can be broadly classified into brittle fracture and plastic fracture. The fracture surface of brittle fracture is usually perpendicular to the tensile stress, and the brittle fracture consists of glossy crystalline bright surface from the macroscopic view; the plastic fracture is usually fibrous with fine dimples on the fracture from the macroscopic view.   The experimental basis of fracture analysis is the direct observation and analysis of the macroscopic morphological and microstructural characteristics of the fracture surface. In many cases, the nature of the f...