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Polyimide (PI) has good mechanical properties and thermal stability, while high coefficient (COF) and wear rate limit its wide application. In order to endow PI with better friction and wear resistance, Mo2Ti2C3 MXene was used as solid lubricant to prepare Mo2Ti2C3/PI nanocomposites with different content of Mo2Ti2C3. The effect of the amount of Mo2Ti2C3 on the tribological behavior of PI was explored and the tribological mechanism was also analyzed Tribological tests showed that at 1.2 wt% of Mo2Ti2C3 addition, the composite material demonstrated superior friction and wear resistance, exhibiting a 19.9% decrease in the COF and a 79.7% decrease in the wear rate compared to single PI due to the good self‐lubricating properties of Mo2Ti2C3 MXene. Moreover, Mo2Ti2C3 can also effectively assist PI to form sleek transfer films without interruption or gaps on the steel balls, resulting in a reduced friction COF and wear rate of the material. This work demonstrates that Mo2Ti2C3 MXene is an aussichtsreich additive for polymers to improve the tribological properties and broadens the applications of Mo2Ti2C3/PI composites in friction material area. Highlights: Mo2Ti2C3 significantly improves the tribological performance of polyimide.The thermal properties of Mo2Ti2C3/polyimide are enhanced by the introduction of Mo2Ti2C3.The minimum coefficient of Mo2Ti2C3/PI composites was only 0.246 at the 1.2 wt% content of Mo2Ti2C3.The wear rate of Mo2Ti2C3/PI composites was decreased by 79.7% at the 1.2 wt% addition of Mo2Ti2C3.Mo2Ti2C3 promotes the establishment of tribo‐film to protect the Mo2Ti2C3/PI composites from friction. [ABSTRACT FROM AUTHOR]

Polyimide (PI) is a special engineering plastic, widely involved in mechanical components, instruments, and petrochemicals. However, single PI material is inevitably subject to wear and tear in practice, which leads to weakened material properties. In this work, Ti3C2Tx@SiO2 was prepared to enhance the wear resistance and lubrication properties of PI by intercalating SiO2 into the interlayer of Ti3C2Tx sheets. Ti3C2Tx@SiO2/PI composites were fabricated in two steps to test the tribological performances. SiO2 particles change the form of interfacial friction from sliding to rolling, thus relieving direct friction between material and steel ball. So, the composites have a minimum COF (COF = 0.33) when the content of Ti3C2Tx@SiO2 is 0.80 wt%. Moreover, the average value of wear rate was 0.24 × 10−5 mm3/(N·m) when Ti3C2Tx@SiO2 content was 1.60 wt%, which was 91.0% lower compared to the PI matrix. During the friction process, the abrasive chips of the material migrate to the surface of the steel ball to form a transfer film, which protects the material and thus reduces the wear rate. Therefore, the hybrids Ti3C2Tx@SiO2 are effective and important wear‐resistant agents and solid lubricants to improve the wear resistance and lubricity of PI or other polymer materials. Highlights: SiO2 insert Ti3C2Tx is a key factor in changing sliding friction into rolling friction, effectively reducing the COF.The average wear rate was 91.0% lower than that of the polyimide matrix when Ti3C2Tx@SiO2 content was 1.60 wt%.The minimum COF of Ti3C2Tx@SiO2/PI composites reached 0.33 when the content of Ti3C2Tx@SiO2 was 0.80 wt%.The transfer film effectively reduces further wear of the material during friction. [ABSTRACT FROM AUTHOR]

Thin‐thickness and lightweight electromagnetic wave (EMW) absorption materials are critically needed for stealth technology in the military stealth field. The special structure of a material is important for improving its good EMW absorption. Herein, a series of porous metal–organic framework‐derived LaCo/C‐decorated Ti3C2Tx (LaCo/C/Ti3C2Tx) composites are prepared by carbonization at high temperatures. Impressively, the minimum reflection loss of LaCo/C/Ti3C2Tx–2 is −47.72 dB at 10.26 GHz (thickness 2.3 mm), and the optimal effective absorption bandwidth is 5.45 GHz (thickness 1.9 mm). The excellent EMW absorption properties are due to multiple electromagnetic loss mechanisms, such as polarization loss, magnetic loss, and multiple reflections and scattering. This work provides a new route for the application of Ti3C2Tx‐based derivatives. [ABSTRACT FROM AUTHOR]

A series of polyimide (PI)/V2CTx MXene composites was synthesized via polyamide acids (PAA) and two‐dimensional (2D) V2CTx MXene obtained by etching precursor V2AlC. PI/V2CTx MXene composites with different mass ratios were obtained by blending and heating with PAA. The results showed that V2CTx MXene has excellent dispersion in PI. In particular, V2CTx MXene exhibited excellent friction reduction and anti‐wear properties as a solid lubricant additive, and the wear rate (WR) was reduced by 43.2% by incorporating only 0.8 wt% of V2CTx MXene in the pristine PI and 71.9% by incorporating 1.2 wt%. Scanning electron microscopy (SEM) and x‐ray photoelectron spectroscopy (XPS) analyses showed that the continuous transfer film consisting of a high proportion of tribo‐chemical products formed on the contact surface is significant to improve the lubrication performances of the PI composites. This work broadens the application of MXene in the field of tribology and contributes to energy conservation and sustainable development of human society. Highlights: The tribological properties could be tuned by changing the ratio of PI to V2CTx MXene.The WR of PI composites was reduced by 71.9% with incorporating 1.2 wt% of V2CTx MXene.The formation of transfer films on the contact surface is significant for improving anti‐wear of PI. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: ZIF‐8 with excellent chemical and physical properties is a promising material for the field of electrochemical sensing. However, the poor electrical conductivity of ZIF‐8 severely limits its electrochemical performance. Here, we report a method that can significantly improve the conductivity of ZIF‐8 by intercalating Ti3C2Tx MXene as a conductive platform. Benefiting from higher conductivity and unique electrocatalytic activity, the obtained MXene/ZIF‐8 nanocomposite presented the worthy analytical performance for hydrazine sensing. The successful fabrication of MXene/ZIF‐8 holds great promise for the design of electrochemical sensors, and it is a promising material to promote the development of new electrode materials. [ABSTRACT FROM AUTHOR]