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Nitrogen adsorption–desorption isotherms of PAs in a the “fixed dianhydride part” and b the “fixed diamine part”, pore size distributions of PAs in c the “fixed dianhydride part” and d the “fixed diamine part”
Source publication
Polyimide aerogels (PAs) using different monomers were prepared by cross-linking with a low-cost aminosilane, bis(trimethoxysilylpropyl) amine. The influence of diamine rigidity and dianhydride rigidity on the microstructure, thermal and mechanical properties of PAs were investigated independently. It was found that Young's modulus and yield streng...
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Thermal insulation and hot oil adsorption have been paid increasing attention to industrial development. Decomposition and combustion of commercial heat insulation materials may happen in the continuously high temperature (≥ 200 °C) or/and instantaneously ultra-high temperature (≥ 250 °C). Nanofiber aerogel with versatile properties is a potential...
Citations
... Furthermore, the residue of the CF-PI-ScD (Et) aerogel composites at 700 °C also remains impressively high, ranging from 74.2% to 83.1% of the initial mass, with . The comparison of the thermal conductivity of CF-PI-ScD (Et) aerogel composites in this study with some other PI aerogels (c), including SiCw/PI aerogel composites [21], double dianhydride backbone PI aerogels [29], SiO2/PI-n aerogels [30], PI/rGO/Co aerogels [31], linear polyimide aerogels (LPAs) [32], PI-PVPMS composite aerogels (PPCAs) [32,33], aromatic PI aerogels [34], MXene/PI aerogels [35], PI/SAp aerogels [36], PI/NH2-HBPSi aerogels [37], nanofiber-reinforced polyimide (NRPI) aerogels [18], BTMSPA cross-linked PI aerogels [38], PI-PMSQ aerogels [39], co-polyimide aerogels [9], melamine-crosslinked polyimide aerogels dried by supercritical CO2 (MPI-C) [25], and ethanol (MPI-E) [26]. The SiCw, rGO, PVPMS, MXene, SAp, NH2-HBPSi, BTMSPA, and PMSQ given here refer to SiC whiskers, reduced graphene oxide, polyvinylpolymethylsiloxane, 2D transition metal carbides and nitrides, silica aerogel powder, amine-functionalized hyperbranched polysiloxane, bis(trimethoxysilylpropyl) amine, and polymethylsilsesquioxane, respectively. . ...
... The SiCw, rGO, PVPMS, MXene, SAp, NH2-HBPSi, BTMSPA, and PMSQ given here refer to SiC whiskers, reduced graphene oxide, polyvinylpolymethylsiloxane, 2D transition metal carbides and nitrides, silica aerogel powder, amine-functionalized hyperbranched polysiloxane, bis(trimethoxysilylpropyl) amine, and polymethylsilsesquioxane, respectively. . The comparison of the thermal conductivity of CF-PI-ScD (Et) aerogel composites in this study with some other PI aerogels (c), including SiCw/PI aerogel composites [21], double dianhydride backbone PI aerogels [29], SiO 2 /PI-n aerogels [30], PI/rGO/Co aerogels [31], linear polyimide aerogels (LPAs) [32], PI-PVPMS composite aerogels (PPCAs) [32,33], aromatic PI aerogels [34], MXene/PI aerogels [35], PI/SAp aerogels [36], PI/NH 2 -HBPSi aerogels [37], nanofiber-reinforced polyimide (NRPI) aerogels [18], BTMSPA crosslinked PI aerogels [38], PI-PMSQ aerogels [39], co-polyimide aerogels [9], melamine-crosslinked polyimide aerogels dried by supercritical CO 2 (MPI-C) [25], and ethanol (MPI-E) [26]. The SiCw, rGO, PVPMS, MXene, SAp, NH 2 -HBPSi, BTMSPA, and PMSQ given here refer to SiC whiskers, reduced graphene oxide, polyvinylpolymethylsiloxane, 2D transition metal carbides and nitrides, silica aerogel powder, amine-functionalized hyperbranched polysiloxane, bis(trimethoxysilylpropyl) amine, and polymethylsilsesquioxane, respectively. ...
Polyimide (PI) aerogels, renowned for their nano-porous structure and exceptional performance across a spectrum of applications, often encounter significant challenges during fabrication, primarily due to severe shrinkage. In this study, we innovatively incorporated ceramic fibers of varying diameters into the PI aerogel matrix to enhance the shape stability against shrinkage. Thestructure of the resulting ceramic fiber-reinforced PI (CF-PI) aerogel composites as well as their performance in thermal decomposition, thermal insulation, and compression resistance were characterized. The results revealed that the CF-PI aerogel composites dried by supercritical ethanol achieved greatly reduced shrinkage as low as 5.0 vol.% and low thermal conductivity ranging from 31.2 mW·m−1·K−1 to 35.3 mW·m−1·K−1, showcasing their excellent performance in shape stability and thermal insulation. These composites also inherited the superior residue-forming ability of ceramic fibers and the robust mechanical attributes of PI, thereby exhibiting enhanced thermal stability and compression resistance. Besides, the effects of different drying conditions on the structure and properties of CF-PI aerogels were also discussed. The coupling use of supercritical ethanol drying with the addition of ceramic fibers is preferred. This preferred condition gives birth to low-shrinkage CF-PI aerogel composites, which also stand out for their integrated advantages include high thermal stability, low thermal conductivity, and high mechanical strength. These advantages attribute to CF-PI aerogel composites substantial potential for a wide range of applications, particularly as high-performance thermal insulation materials for extreme conditions.
... The characteristics of PSPI are mainly dominated by the material composition of the precursor. To obtain PSPI with low CTE, pyromellitic dianhydride (PMDA) structures, pphenylenediamine (PPDA) or other rigid structure monomers were commonly selected as monomers of precursor due to the high rigidity, as shown in Fig. 2 [11]. ...
In advanced packaging schemes, such as fan-out integration technology, photosensitive polyimide (PSPI) is the key material to the fabrication of panel level redistribution-layer (RDL). However, a large mismatch of coefficient of thermal expansion (CTE) between silicon (Si) and PSPI will cause serious warpage issue. Furthermore, polyimide deformation may occur under external heat and pressure, leading to deterioration of RDL reliability. In this work, PSPI with low CTE and excellent adhesion strength on different substrate was developed and evaluated by lithography test, adhesion test, and reliability test, showing the high feasibility for the application in advanced packaging process.
... In recent years, a variety of PI aerogels have been reported, whose shrinkage is not satisfactory and needs to be further addressed. For instance, Xi et al. used rigid diamine and dianhydride to prepare PI aerogels, resulting in varying shrinkage (14.3-45.1 vol.%) and densities (0.133-0.379 g cm −3 ) [10]. Zhu et al. reported that the shrinkage of PI aerogel composites reinforced by glass fibers varied from 16.5 to 57.9 vol.% [11]. ...
... Nevertheless, the maximum shrinkage observed in this study was only 16.32 vol.%, much lower than those reported in previous studies [14]. The shrinkage and density of some other PI aerogels compared to CF-PI aerogel composites are shown in Fig. 4 [10][11][12][13]16]. ...
Melamine-crosslinked polyimide (MPI) aerogels are promising for diverse applications owing to their economical cost and impressive performance. However, MPI aerogels tend to suffer severe shrink in the processes of preparation and practical applications. Their upgrades, i.e., carbon foam-reinforced polyimide (CF-PI) aerogel composites, therefore were proposed in this study, to address this issue. The structure, thermal insulation of the resultant composites as well as their mechanical strength were characterized. The CF-PI aerogel composites were observed to have low shrinkage (as low as 9.25 vol.%) and low thermal conductivity (21 mW m⁻¹ k⁻¹–34 mW m⁻¹ k⁻¹), indicative of significantly improved shape stability and exceptional thermal insulation capability. Besides, these aerogel composites also performed well in thermal stability, and did not decompose unless the temperature exceeds 400 °C. All these advantages contribute to the broad application prospects of thus aerogel composites in many aspects, such as thermal insulation for high temperatures, and so on.
Graphical Abstract
The composite is apparently composed of carbon foam and PI aerogel. Of the two, the carbon foam itself serves as a support frame, and PI aerogel is filled inside as the functional component. When the polymer concentration increases from 4 to 8%, the shrinkage of CF-PI aerogel composites gradually increases.
