The physical properties and structural differences in microcrystalline cellulose (MCC) and nanocellulose (NC) lead to their different ease of preparation into powders. Microcrystalline cellulose (MCC): Microcrystalline cellulose is a polymer composed of the crystalline region portion of cellulose, with a short fiber length and a lower specific surface area. This structure makes microcrystalline cellulose have high stability and can be easily ground into a fine powder. Since the particles of microcrystalline cellulose are coarse and do not easily adhere to each other or form agglomerates, powders can be made by conventional drying and crushing methods. Nanocellulose (NC): Nanocellulose consists of smaller fibrous nanostructures, generally between 1-100 nanometers in diameter and can reach several microns in length. Its specific surface area is very large, resulting in a significant increase in surface energy. This high surface energy makes nanocellulose particles very easy to adhere to each other or form aggregates. Nanocellulose has a high level of

There are some research and practical cases of the application of nanocellulose as an additive in oil well drilling fluids. Its main function is to improve the rheological performance of drilling fluids, reduce filtration loss, enhance well wall stability and improve drilling efficiency. The specific amount of addition and use effect will vary depending on the drilling conditions, type of drilling fluid (such as water-based or oil-based drilling fluid) and the modification type of nanocellulose. Here are some common use cases and added information: 1. Improve the rheological properties of drilling fluids Nanocellulose can increase the viscosity and thixotropy of drilling fluids, making it easier to carry drilling chips and improve shear thinning of drilling fluids characteristic. The addition amount is usually between 0.1% and 1.5% (mass fraction)**, and the rheological parameters of the drilling fluid are adjusted as needed. Case: Studies have shown that when using unmodified cellulose nanofibers (CNF) as additives for water-based drilling fluids, adding 0.5%** can significantly increase the viscosity of the drilling fluids.

The application of nanocellulose in anticorrosion coatings is increasingly attracting attention, mainly because it can improve the mechanical properties of the coating, increase shielding effect, reduce the permeability of water vapor and oxygen, thereby enhancing the anticorrosion performance. Here are some information about the use cases and typical additions of nanocellulose in anticorrosive coatings: 1. Improve mechanical strength and adhesion Nanocellulose, especially cellulose nanofibers (CNF), due to their high specific surface area and High strength characteristics can effectively increase the mechanical strength and adhesion of the coating, thereby extending the service life of the coating. Case: Adding 0.5% to 2.0% (mass fraction) of cellulose nanofibers to the epoxy resin coating can significantly improve the tensile strength and wear resistance of the coating, making it more suitable for anti-corrosion scenarios. 2. Improve shielding performance, reduce the aspect ratio and dispersion of permeable nanocellulose can form a 'maze'-like structure in the coating, thereby increasing water vapor and

The basic principle of determining the molecular weight of cellulose by terminal group analysis is to quantify specific functional groups at the end of the polymer chain through chemical or physical methods, and then calculate the average molecular weight. The terminals of cellulose often contain groups such as hydroxyl groups (-OH), so molecular weight can be estimated by detecting the concentration of these terminal groups. Detailed steps: 1. Sample preparation Dissolve the cellulose sample in an appropriate solvent to ensure complete dissolution. Cellulose molecules are not easy to dissolve, and a suitable solvent system is required to choose, such as dimethylacetamide-lithium chloride system (DMAc/LiCl), or alkaline aqueous solution. 2. The commonly used methods for calibration of terminal groups in chemical reactions include esterification or acylation reaction, which modify the hydroxyl group (-OH) at the terminal of cellulose molecules. For example, acetylation reaction is used to react with the terminal hydroxyl group to form an acetate. The product generated after the reaction is then determined by titration or other quantitative analysis techniques, thereby indirectly calculating the concentration of the terminal hydroxyl group.

Gel Permeation Chromatograph (GPC), also known as size exclusion chromatography (SEC), is an analysis method based on molecular volume differential separation of polymers. It is widely used to determine the molecular weight and molecular weight of polymers. distributed. GPC is suitable for determining the molecular weight of polymer materials such as cellulose. The following are the steps and detailed principles for determining the molecular weight of cellulose using GPC. 1. Basic Principle GPC separates molecules of different sizes by using a chromatographic column with porous fillers. Since macromolecules cannot enter small pores, they will pass through the column first, while small molecules can enter pores, thus delaying their outflow. By analyzing the retention time of the molecules in the chromatographic column, the molecular weight of the molecules can be calculated. Results of GPC usually include: • Number average molecular weight (Mn): Indicates the average molecular weight of all molecules in the sample. • Weight average molecular weight (M

Nuclear magnetic resonance (NMR) spectroscopy can be used to determine the molecular weight of cellulose, but this process is more complicated because the structure of cellulose is large and complex. Here are the general steps for determining cellulose molecular weight using NMR method: 1. Sample preparation • Purify the sample: Make sure the cellulose sample is as pure as possible and remove other impurities. • Dissolved sample: Cellulose is not easily dissolved in water and therefore requires dissolving with a suitable solvent system, such as sodium dihydrogen phosphate solution (e.g., 6% sodium phosphate solution) or other solvent systems. 2. NMR Experiment • Select the appropriate NMR frequency: Use high-field NMR instruments, such as instruments with a frequency of 300 MHz or higher, to obtain a clear spectrum. • Obtain spectra: Perform a solid or solution NMR experiment, and obtain a ¹³C-NMR or ¹H-NMR spectrum of cellulose according to the experimental settings. ¹&su

The viscosity method is a simple and effective method to determine the molecular weight of polymers, and is often used to determine the relative molecular weight of polymers such as cellulose. The specific process is based on the relationship between the intrinsic viscosity of the solution and the molecular weight of the polymer. The following are the general steps and principles for determining the molecular weight of cellulose by using the viscosity method: 1. Basic Principle In the viscosity method, by measuring the viscosity of cellulose solution and combining empirical formulas (such as Mark-Houwink equation), the average cellulose can be calculated. Molecular weight. The viscosity measurement method depends on the relationship between the viscosity and molecular weight of the polymer solution, i.e.: [η]=K⋅Mva where: • [η] is the intrinsic viscosity of cellulose (unit: dL/g) and is from the solution. A dimensionless value derived from the viscosity data. • Mv is the viscosity average molecular weight of cellulose. • K and

Determining the molecular weight of cellulose using ultracentrifugation is not a standard method, but the following steps can be tried. The basic idea of ​​this method is to use the settlement behavior of cellulose in the centrifugal field to infer its molecular weight. 1. Prepare sample and solution sample preparation: Dissolve cellulose in a suitable solvent. Commonly used solvents include amino acid salt solutions, ionic liquids or other solvents that can dissolve cellulose. The solubility of cellulose is usually low, so it may be necessary to choose suitable solvents and conditions. Solution preparation: Dissolve cellulose into a solution of a certain concentration and ensure that the solution is uniform. The complete dissolution of the cellulose can be ensured by ultrasonic treatment or other methods. 2. Ultracentrifuge experimental equipment settings: Use an ultracentrifuge (such as a liquid centrifuge) and select the appropriate rotor and speed as needed. Common speed ranges are hundreds of thousands to millions (centrifugal acceleration). Centrifugal conditions: Select the appropriate centrifugal conditions (transfer

Precipitation titration is a method of calculating the molecular weight of the polymer by reacting the terminal groups of the polymer with a specific reagent, and calculating the amount of precipitate produced by titration. For cellulose, titration assays are usually performed for terminal hydroxyl or carboxy groups. The following are the detailed steps: 1. Sample preparation Sample dissolution: Cellulose dissolves in the solvent to ensure uniform dispersion. For cellulose, solvent systems such as DMAc/LiCl can be used. 2. Select a suitable titrator for chemical reactions: Select a suitable precipitant according to the properties of the terminal groups of the cellulose. The titrator commonly used for carboxyl groups is silver ion solution (AgNO₃), which reacts with terminal carboxyl groups to form an insoluble precipitate (such as AgCl). 3. Titration step Mix the cellulose solution with the reaction reagent (such as AgNO₃) to observe the process of producing precipitation. Add AgNO₃ dropwise until no new precipitation is generated (end point can be passed by indicator

Light scattering is an analysis technology based on the interaction between light and matter, and is widely used to determine the molecular weight and molecular size of polymers (such as cellulose). The light scattering method is mainly divided into two types: static light scattering (SLS) and dynamic light scattering (DLS). Among them, static light scattering is used to measure the weight average molecular weight (Mw), root mean square rotation radius (Rg) and second veri coefficient (A2) of the polymer; dynamic light scattering is used to measure the diffusion coefficient and hydrodynamics of particles. Radius (Rh). The following will describe in detail how to determine the molecular weight of cellulose using light scattering method. 1. Basic Principle 1.1 Static Light Scattering (SLS) When a monochromatic, parallel light is irradiated into a polymer solution, the polymers in the solution will cause light scattering. The intensity of scattered light is related to parameters such as molecular weight, concentration and molecular size of the polymer. According to Rayleigh scattering theory, for small particles (particle size is much smaller than the wavelength of light), the scattered light intensity and molecules