Excellent Lubricating Properties Research Articles

Mitigating intubation stress, mucosa injury, and inflammatory response in nasogastric tube intubation via suppression of the NF-κB signaling pathway by engineering a hydration lubrication coating.

Nasogastric tube (NGT) intubation is a common yet critical clinical procedure. However, complications arising from tube friction result in awful pain and morbidity. Here, we report a straightforward surface modification of slender NGT utilizing highly hydrated micelles that were composed of hyaluronic acid and Pluronic. The strong intermolecular hydrogen bonding facilitated the assembly of the micelles on NGT via a one-step dip coating process. The micelle coating conferred excellent hydrophilic, lubrication, anti-protein adhesive, and biocompatible properties. The in vivo efficacy of the micelle coating in alleviating catheterization irritation and mucosal injury was demonstrated using an NGT intubation model of rabbits. More importantly, compared to the paraffin oil coating (the current clinical means), the micelle coating possessed superior capability to reduce the inflammatory reaction caused by NGT intubation. The underlying mechanism was attributed to the suppression of the TLR4-IKBα-NF-κB inflammatory signaling pathway. This work provides a promising solution for developing lubricant medical coatings.

Crosslinked Polymer Coatings of Poly (Acrylic Acid-co-acrylamide)/Polyethyleneimine (P(AA-co-AAm)/PEI) on Titanium Alloy with Excellent Lubrication Performance for Artificial Joints

The development of coatings with efficient lubrication and load-bearing capacity is an urgent need for artificial joints. Here, we successfully fabricated poly (acrylic acid-co-acrylamide)/polyethyleneimine (P(AA-co-AAm)/PEI) coating on titanium alloy (Ti6Al4V) surface via UV irradiation and thermal treatment technique. The dual crosslinked network structures were composed of a P(AA-co-AAm) network via free radical polymerization and a PAA-co-PEI network via thermal crosslinking of amine and carboxyl groups. The thermally crosslinked P(AA-co-AAm)/PEI coatings exhibit a stable low friction coefficient (approximately 0.022) and exceptionally low wear volume, with a 93.8% and 92.6% reduction, respectively, in comparison to the pristine Ti6Al4V. These thermally crosslinked P(AA-co-AAm)/PEI hydrogel coatings exhibit excellent lubrication and anti-wear properties, providing a strategy for developing novel lubricating coatings in the biomedical field.

Surface Forces Characterization of Concentrated PMMA Brush Layers under Applied Load and Shear.

Concentrated polymer brushes (CPBs) are known to exhibit excellent lubrication properties. However, the frictional behaviors of CPBs vary, depending on their preparation and operating conditions. In order to understand such complicated properties, it is necessary to determine their structures and correlate them with their properties, during shear motion. In this study, we employed surface forces and resonance shear measurement (RSM) as well as refractive index measurement using fringes of equal chromatic order (FECO) for studying the structure of the CPBs of poly(methyl methacrylate) (PMMA) in toluene. The obtained elastic (ks) and viscous (bs) parameters based on the RSM for the PMMA-PMMA were higher than those obtained for PMMA-silica over the entire distance range. With the increasing shear amplitude on the PMMA-PMMA under an applied load, the bs value first increased and then decreased while the ks value monotonically decreased. These behaviors were consistent with those of the thicker CPBs reported in a previous paper (Soft Matter, 2019). Thus, the dynamics of the CPBs under the applied load and shear were not dependent on the thickness of the polymer brushes in this case. The density distribution of the swollen PMMA brushes along the distance in the thickness direction of the brush layer was estimated by using the measured refractive index values, showing that the fraction of the PMMA brushes in the outer region from the surface (20% in the thickness) was ca. 10%. This lower density region near the surface of the swollen CPBs enabled them to interpenetrate with each other. Changes in the refractive index value under shear were observed, indicating that the interpenetrated PMMA chains were pulled out with increasing shear amplitude. These results demonstrated that broader applications of CPBs are possible by regulating the friction between them under different operating conditions, even for usually lubricious CPBs.

The cooperatively crosslinking between GO-COOH/TiO2 @PAO microcapsules and polyimide to improve the mechanical and tribological properties of PEEK/PI composites

The PEEK fabric-reinforced polyimide resin containing microcapsules with excellent mechanical and lubrication properties is reported. The GO-COOH/TiO2 @PAO double-wall microcapsules (Capsule) were prepared by interfacial condensation polymerization of titanium butoxide (TBT) and self-assembly between GO-COOH and TiO2 shell. A double crosslink of chemical bond (amide or ester) and hydrogen bond were constructed between microcapsules and polyimide (PI) to improve the mechanical properties of PEEK fabric-reinforced polyimide resin (PEEK/PI). It was identified that the addition of Capsules induced a 12.98% decrease in friction coefficient and 56.85% in the wear rate of the composites. This superior frictional behavior was primarily attributed to the combined effect of the boundary lubrication of PAO6, load-bearing effect of TiO2 and PEEK fabric, and friction-reducing of GO-COOH.

Bionic sweat high temperature self-lubricating coating based on ceramic precursor polysilazanes

Bionic sweat high temperature self-lubricating coating were prepared using ceramic precursor polysilazane and MoS2, Ag and BaF2 as fillers through high temperature chemical reaction to produce ceramic adhesive and molybdate solid lubricants. And the addition of active ZrB2 filler converted into ZrO2 and B2O3 through high temperature oxidation reaction not noly solved the cracking issues caused by the pyrolysis of polysilazane, but also enhances the tribology property due to the excellent fluidity and lubricity of the molten B2O3 through phase transition at high temperature through bionic sweat. Furthermore, the coating treated at 700 °C has the best lubrication performance at 500 °C, 2 N and 100 rpm that the friction coefficient was 0.223 and the wear rate was 1.53 × 10−4 mm3/N·m, respectively. Synergistic effect of solid lubricants and molten B2O3 leads to excellent lubrication property.

Oil-soluble deep eutectic solvent functionalized graphene oxide towards synergistic lubrication in non-polar PAO 20 lubricant

Although deep eutectic solvents (DESs) have shown excellent surface modification and lubrication properties, there have been seldom reports concerning the effect of those characters on the tribological behavior of nanoparticles as non-polar oil additives. Here, we grafted tetrabutylammonium chloride and octanol-based oil-soluble DES onto the base plane or interlayer of GO through a long aliphatic chain, chloride ion and C-N covalent functionalization, forming functionalized GO (DES/GO). The DES/GO could well disperse in a nonpolar polyalphaolefin base oil (PAO 20) to construct DES/GO hybrid PAO 20. Moreover, the friction and wear of DES/GO hybrid PAO 20 oil decreased by 35% and 41% compared with those of pure PAO 20 oil. The splendid interfacial lubrication depends on the formation of uniform, dense, and strong graphene-like tribofilm to shield the tribo-interfaces against wear. And the grafted DES on GO further participates in the tribochemical reaction to form the FexOy, FeCl2 or FeCl3 and tetraalkylammonium salt tribochemical film. The self-lubricating performance of GO and tribochemical reaction of DES together achieve a synergistic lubrication effect.

Bioinspired Hard–Soft Composite Scaffold with Excellent Lubrication and Osteogenic Properties for the Treatment of Osteochondral Defect

AbstractNatural articular cartilage is a typical self‐healing and superlubrication system capable of maintaining extremely low friction under physiological loadings. Cartilage wear and accidental trauma can cause irreversible defects to cartilage and subchondral bone with a significant decrease in intra‐articular lubrication, leading to the development of severe osteoarthritis and osteochondral defect. To address the important clinical problem of osteochondral defect, a bioinspired hard–soft (PEEK‐lubrication hydrogel) composite scaffold is designed and developed. The polymerization of polyethylene glycol diacrylamide (PEGDAA) and 2‐methacryloyloxyethyl phosphorylcholine (MPC) on polyetheretherketone (PEEK) substrate is achieved by UV initiation to form a strong interfacial bonding, and nano‐hydroxyapatite is deposited on porous PEEK substrate via polydopamine coating to improve osteogenic capability. Accordingly, the composite scaffold is successfully developed with lubrication and osteogenic activity. The tribological tests show that the lubrication performance of the composite scaffold is based on the hydration lubrication mechanism of the upper hydrogel layer, and the in vitro and in vivo experiments demonstrate that the composite scaffold is endowed with excellent biocompatibility and bioactivity. In conclusion, the bioinspired strategy for preparing a hard–soft composite scaffold shows a promising way in the treatment of osteochondral defect and provided a guideline for designing functional PEEK‐based biomaterials in tissue engineering scaffolds.

Ultralow friction polymer composites enabled by the solid–liquid core microcapsules at high temperatures

The application of oil-containing microcapsules for lubrication at high temperatures has been a great challenge due to the volatilization and viscosity reduction of the oil. In this study, thermostable SiO2 was selected as the shell and WS2 silicone oil dispersion as core to prepare heat-resisting solid–liquid compound microcapsules. The tribological properties of the composites at high temperatures were evaluated, and the lubrication mechanism of the solid–liquid coupled microcapsules was investigated. The results showed that the microcapsule composites were able to maintain low friction coefficient (COF) and wear rates at high temperatures (COF of 0.098, 73 % lower than pure epoxy, and wear rate of 4.87 × 10-6 mm3/N·m, two order of magnitude lower than pure epoxy, at 300 ℃), and in addition, the compressive strength of the composites was improved due to the excellent mechanical properties of SiO2. The strategy proposed in this study is expected to be a general solution and can be extended to other polymer composites with excellent high-temperature lubrication properties by incorporating microcapsules with different solid–liquid core in the matrix.

Effects of Ni/MoS2, Ag and Cr2O3 on the Microstructure and Mechanical Performance of a CoCrFeNi High-Entropy Alloy over a Wide Temperature Range

In the field of aerospace, core components require excellent wear resistance, lubrication and mechanical properties over a wide temperature range. In this study, three groups of CoCrFeNi high-entropy alloy (HEA)-based self-lubricating composites were designed with the addition of Ag, Ni/MoS2 and Cr2O3 using discharge-plasma-sintering technology. Their microstructure, phase composition, mechanical properties, friction and wear properties were analyzed. The results showed that, with the addition of Ag, the hardness and yield stress of HEA-Ni/MoS2-Ag were reduced by 36 HV and 24 MPa, respectively, while the plastic strain was increased by 2%. With the addition of Cr2O3, the hardness (382 HV) and yield stress (430 MPa) of HEA-Ni/MoS2-Ag-Cr2O3 reached their highest values, but the plastic strain reached its lowest value. HEA-Ni/MoS2-Ag-Cr2O3 had the smallest friction coefficient in which the friction coefficient at 800 °C was only 0.42. Additionally, it had a small wear rate of 3.2 × 10−6 mm3/Nm over a wide temperature range. At lower temperatures, Ni/MoS2 and Ag were conducive to lubrication, and the wear resistance was improved by the presence of Cr2O3. At high temperatures, a nickel oxide phase and a variety of silver molybdate phases were formed via a tribochemical reaction, which was vital to the high-temperature tribological properties.

Excellent corrosion inhibition and lubrication properties of carbon dot-based ionic liquids as water-based additives

Ionic liquids (ILs) and carbon dots (CDs) have gained more attention as versatile materials. Noticeably, the carbon dot-based ionic liquids (CDILs), a novel ionic combination of the two materials, will be endowed with superior performance and promote the application of CDs in fields of corrosion inhibition and lubrication. In this work, three CDILs with different alkyl chain numbers were synthesized as water-based multifunctional additives. CDILs show excellent corrosion inhibition effect in corrosive aqueous solution and superior lubricating behavior in water. Interestingly, CDILs with medium numbers of alkyl chains in cationic moiety exhibits optimal corrosion inhibition and lubrication performance. Both the physical adsorption of CDILs and the structures of cations influence the quality of adsorption and lubricating film.

Tribochemistry effect on the friction reduction of Al2O3/ethylene glycol composite lubricant between steel self‐mated tribosystem

In our previous work, we find that the ethylene glycol (EG) is transferred to amorphous carbon or graphene during sliding under the effect of the tribochemical reactions; herein, in this work, we control the concentration of the modified Al2O3 nanoparticles in the EG solution in order to modulate the tribological properties of the tribosystem sliding in the mixed lubricant consisting of the modified Al2O3 nanoparticles and EG. The tribological tests show that the concentrations of the modified Al2O3 nanoparticles ranging from 0 to 1.0 wt% in the mixed lubricant are helpful for obtaining low wear rate due to the formation of graphene‐like materials induced by tribochemical reactions. On the other hand, when the concentration reaches 1.5 wt.%, the tribosystem exhibits high coefficient of friction (COF) and wear rate, which is attributed to the formation of reunited groups consisting of the modified Al2O3 nanoparticles and graphene‐like materials. This investigation should give a positive guidance for the design of the mixed lubricant with excellent lubrication properties.

Fabrication of carbon dots@2D CuCo-MOF composites as lubricating additives in pentaerythritol ester for enhanced tribological properties at elevated temperatures

In this study, we successfully synthesized CD@CuCo-MOF composites, which are composed of ultrathin two-dimensional (2D) nanosheets of metal-organic framework (MOF) doped with carbon dots (CDs). The synthesis process involved hydrothermal and ultrasonically assisted self-assembly with a proper solvent ratio. The composites were then dispersed into pentaerythritol ester (PETE) with the aid of ultrasonic treatment. We thoroughly evaluated the physicochemical features and tribological properties of the CD@CuCo-MOF composites using advanced testing and characterization techniques including XRD, Raman, FTIR, TG, XPS, FIB-TEM and so on. The results demonstrated that the addition of CD@CuCo-MOF resulted in a 61.1 % reduction in the coefficient of friction (COF) at a concentration of 0.1 wt% when compared to the base oil at room temperature. With the rise in temperature, CD@CuCo-MOF exhibited excellent lubricating properties due to its hybrid inorganic-organic structure and interlayer sliding effect. This led to a reduction of 59.2 % and 42.9 % in the mean COF compared to PETE oil at temperatures of 100 °C and 200 °C. This enhancement in the tribological performance of CD@CuCo-MOF could be attributed to several factors, including its superior dispersion stability, excellent lubricating properties, and involvement in the formation of a tribofilm. The tribofilm formed from a combination of CDs, CuCo-MOF, metal oxides, carbides, and nitrides promoted the rearrangement of the contact surface, thereby minimizing the friction and wear between the rubbing surfaces. These findings hold significant guiding implications for advancing the development of potential-controlled lubrication using MOFs doped with CDs across a wide temperature range.

Functional nano drug delivery system with dual lubrication and immune escape for treating osteoarthritis

Local drug delivery via inter-articular injection offers a promising scenario to treat the most common joint disease, osteoarthritis (OA), which is closely associated with the increased friction or cartilage degeneration and the inflammatory syndrome of synovium. Therefore, it is quite necessary to improve the retention of drug delivery system within synovial joint, simultaneously restore the lubrication of degraded cartilage and meanwhile alleviate the inflammation. In this study, we propose a hydrophilic coating modified nano-liposome drug carrier (PMPC-Lipo) to achieve these functions. A modified chain transfer agent was utilized to polymerize 2-methacryloyloxyethyl phosphorylcholine (MPC), the obtained polymer, combined with lecithin and cholesterol, formed a liposome (PMPC-Lipo) where poly (MPC) acted as hydrophilic coating. PMPC-Lipo was found to restore the lubrication of mechanically damage cartilage (mimicking OA conditions) to the level like healthy cartilage due to the hydration lubrication. Additionally, due to the presence of poly (MPC), we also found PMPC-Lipo avoid the recognition of macrophage and thus escape from the phagocytosis to prolong its retention in synovial joint. Furthermore, after encapsulating gallic acid (GA) into PMPC-Lipo, the obtained GA-PMPC-Lipo can effectively scavenge reactive oxygen species and restore the imbalance of matrix secretion in inflammatory chondrocytes. Collectively, the proposed GA-PMPC-Lipo may provide a new idea for osteoarthritis treatment by providing both long-term effective drug action and excellent lubrication properties.

Refractory high-entropy aluminized coating with excellent oxidation resistance and lubricating property prepared by pack cementation method

Refractory high-entropy alloys (RHEAs) exhibit superior mechanical properties at high temperatures compared to that of conventional high-temperature alloys. However, some refractory metallic elements are highly susceptible to oxygen absorption at room temperature and the resulting oxide films are not protective, resulting in catastrophic oxidation before they can exhibit excellent mechanical properties. Therefore, it is essential for them to improve the high-temperature oxidation properties of RHEAs. The pack cementation method can be used to prepare the aluminized coatings on the surface of RHEAs to improve their high-temperature oxidation resistance. In the present work, the aluminized high-entropy coatings were prepared on the surface of as-cast Ta25Nb25W25V25 RHEAs. The diffusion activation energy required for aluminization was experimentally calculated to be 137.667 kJ/mol, thus the growth kinetics of the coating was constructed. Aluminized coatings with the thickness of ∼75 μm and Vickers hardness of ∼680 HV0.01 obtained by holding at 1100 °C for 9 h were selected for the study. The oxidation activation energy of the aluminized coating at 800–1000 °C was 96.981 kJ/mol, while that of as-cast RHEAs was only 48.816 kJ/mol, so the oxidation resistance of the specimen was greatly improved. At 20–600 °C, the aluminized coatings also exhibited excellent wear resistance and lubrication properties. In particular, the average coefficients of friction were reduced by 0.13–0.24 compared to that of as-cast RHEAs, which can be attributed to the AlW intermetallic compound particles formed within the aluminized coating acting as self-lubricating particles.

Facile Synthesis of Lignin-Castor Oil-Based Oleogels as Green Lubricating Greases with Excellent Lubricating and Antioxidation Properties

Facile Synthesis of Lignin-Castor Oil-Based Oleogels as Green Lubricating Greases with Excellent Lubricating and Antioxidation Properties

In-situ exfoliation of large sized h-BNNS by esterified nanocellulose to build aqueous lubricants that can switch between liquid and gel states

The development of cellulose-based aqueous dispersions provides new ideas for the preparation of green lubricants. Herein, an esterified cellulose-assisted in-situ exfoliation (ECAIE) method was used to produce large lateral sized 2D materials in cellulose dispersions which with excellent dispersion stability. Taking h-BN as an example, the ECAIE method produces NC@h-BNNS aqueous dispersion with lateral size of h-BNNS reaching 1200 nm, exhibiting excellent lubrication properties. The obtained aqueous lubricants show the ability to switch between liquid (oscillation) and gel (resting) states. This method was also extended to the production of aqueous dispersions of various other cellulose/2D materials, and the efficient lubrication of the resulting dispersions on engineered steel surfaces has been demonstrated, indicating their great potential in the field of lubrication.

The Synthesis of Cu-Coated Ti2SnC Ceramic and Its Tribological Behaviors as a Lubricant Additive

Lubricant additive plays an important role in reducing the friction and wear for base oil. MAX phase ceramics may have superior advantages for additive application due to their unique nanolayered structure. In this paper, Ti2SnC ceramic is prepared by sintering the elemental mixtures at 1250 °C. In addition, Cu-coated Ti2SnC ceramic is successfully prepared using a chemical plating method for the first time. It is confirmed that the Ti2SnC ceramic has good self-catalytic activity, and a layer of stacking Cu nano-particles can be deposited on the Ti2SnC surface without pretreatment. When the Cu-coated Ti2SnC ceramic powder is doped into PAO10 base oil, the oil can exhibit excellent lubrication properties, where the friction coefficient is as low as 0.095. A layer of tribo-film can be formed during the sliding process when the Cu-coated Ti2SnC ceramic is incorporated into PAO10 base oil, which can reduce the friction coefficient. The superior lubrication properties can be attributed to the synergistic lubrication effect of Ti2SnC ceramic and Cu nano-particles.

Spectroscopic Evaluation of Surface Chemical Processes Occurring in MoS2 upon Aging.

Molybdenum disulfide (MoS2) coatings have attracted widespread industrial interest owing to their excellent lubricating properties under vacuum and inert conditions. Unfortunately, the increase in MoS2 interfacial shear strength following prolonged exposure to ambient conditions (a process referred to as "aging") has resulted in reliability issues when MoS2 is employed as solid lubricant. While aging of MoS2 is generally attributed to physical and chemical changes caused by adsorbed water and/or oxygen, a mechanistic understanding of the relative role of these two gaseous species in the evolution of the surface chemistry of MoS2 is still elusive. Additionally, remarkably little is known about the effect of thermally- and tribologically-induced microstructural variations in MoS2 on the aging processes occurring in the near-surface region of the coating. Here, we employed three analytical techniques, namely, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS), and grazing-incidence X-ray diffraction (GIXRD), to gain insights into the aging phenomena occurring in sputtered MoS2 coatings before and after tribological testing, while also evaluating the impact of thermally-induced variations in the coating structure on aging. The outcomes of XPS analyses provide evidence that a substantial surface oxidation of MoS2 only takes place under humid conditions. Furthermore, the correlation of XPS, ToF-SIMS, and GIXRD results allowed for the development of a qualitative model for the impact of shear-induced microstructural variations in MoS2 on the transport of water in the near-surface region of this material and on the extent of surface oxidation. These results add significantly to our understanding of the aging mechanisms of MoS2 coatings used in tribological applications and their dependence on environmental conditions.

A comprehensive ab-initio insights into the pressure dependent mechanical, phonon, bonding, electronic, optical, and thermal properties of CsV3Sb5 Kagome compound

In this paper, we have presented a comprehensive study of the physical properties of Kagome superconductor CsV3Sb5 using the density functional theory (DFT) methodology. The structural, mechanical, electronic properties (band structure, electronic energy density of states, Fermi surface, and charge density distribution), atomic bonding, hardness, thermodynamics, optical properties, and their pressure dependences have been investigated systematically at different pressures. The calculated ground state lattice parameters and volume are in excellent agreement with available experimental results. The estimated single-crystal elastic constants ensured the mechanical stability of the compound, whereas phonon spectra endorse dynamical stability at zero pressure. The electronic band structure, density of states, and optical properties confirmed the metallic feature. The Pugh ratio and Poisson’s ratio of the compound under study revealed the softness/ductility. The hardness of CsV3Sb5, estimated using several formulae, is quite low while the machinability index predicted good machinability with excellent lubricating properties. The compound shows tendency towards structural instability at a pressure around 18 GPa. The optical constants have also been studied to correlate them with electronic properties (band structure) and predict the possible applications of this compound. Both the mechanical and optical properties show directional anisotropy. CsV3Sb5 is predicted to be an efficient absorber of ultraviolet radiation. The compound is also an efficient reflector of visible light. The superconducting transition in CsV3Sb5 has been revisited following prior studies.

Preparation and Performance Evaluation of Polyacrylamide Hydrogel Coating on the Surface of Silicone Rubber Nasogastric Tube

To prepare the hydrogel coating on the surfaces of nasogastric tubes and to evaluate its effect on the insertion of nasogastric tubes in a rabbit model. The polyacrylamide (PAAm) hydrogel coating was prepared by UV-induced free radical polymerization. The morphology of the PAAm coating and its interfacial bonding with the silicone rubber substrates of nasogastric tubes were observed with scanning electron microscope. The composition of the coating was analyzed by Fourier transform infrared (FTIR) spectrometer and X-ray photoelectron spectrometer (XPS). The water absorption power and stability of the coating were measured by the weighing method. Water contact angle meter was used to measure the wettability of the coating and tribometer was used to determine the friction coefficient of the silicone rubber substrates before and after the modification. The cytotoxicity of the coating on L929 murine fibroblast cell line was explored with CCK-8 assay after 24-h coculturing of the L929 cell line with silicone rubber substrates before and after modification. An animal model of nasogastric tube insertion in New Zealand rabbits was used to evaluate the effect of the lubrication coating by assessing the insertion time and nasal damage. In this study, PAAm hydrogel coating was prepared and constructed on the surface of silicone rubber nasogastric tubes. The coating, with a three-dimensional network structure, showed strong interfacial bonding with silicone rubber substrates. The appearance of amino and carbonyl groups indicated that the PAAm hydrogel coating was grafted on the surfaces of nasogastric tubes. Before the modification, the silicone rubber substrate essentially did not absorb much water, whereas, after the modification, the silicone rubber substrate showed significant improvement of as much as 2.9% in water absorption. After sonication for 90 min, the weight loss rate was only 0.15%. Compared with pristine nasogastric tubes, the water contact angle of the modified nasogastric tubes was reduced from 111.9°±2.2° to 58.9°±1.5° ( t=22.59, P<0.05). In addition, the friction coefficient of silicone rubber nasogastric tubes decreased by 69.3% from 0.378±0.05 to 0.116±0.004 ( t=42.80, P<0.05) after modification. Moreover, there was no significant difference in the cytocompatibility between L929 cells cocultured with pristine nasogastric tube and those cocultured with modified nasogastric tube. The animal experiment of nasogastric tube insertion showed that the insertion time of the modified nasogastric tubes was reduced from (41.6±7.8) s to (12.4±2.9) s ( t=8.509, P<0.05). Laryngoscopy revealed that the PAAm hydrogel coating significantly reduced the mucosal damage caused by the insertion of nasogastric tubes. In this study, PAAm hydrogel coating with strong interfacial bonding was prepared on the surface of silicone rubber nasogastric tubes. The coating has excellent hydrophilic lubrication property and cytocompatibility, effectively shortens the insertion time, and reduces the damage caused by nasogastric tube insertion.