Novel design of alumina foams with three‐dimensional reticular architecture for effective high‐temperature particulate matter capture

Abstract

Ceramic foams with extensive interconnected pores have great application potential in high‐temperature particulate matter (PM) capture. Considering that there are still challenges to synthesize ceramic foams with efficient filtration, a novel hierarchical‐structured alumina foam with three‐dimensional (3D) reticular architecture has been fabricated via combining chemical grafting pore‐forming agent and polyurethane (PU) foaming technology. Carbon black is grafted with carbamate functional groups in order to enable a better dispersion in highly viscous PU. Submicrometer and micrometer‐sized pores on the cell walls are observed in hierarchical‐structured ceramic foams. The resulting alumina foam exhibits 95.2% removal efficiency for PM particles and low pressure drop of only 50 Pa when grafted carbon black content is 3 wt%. This filtration performance is much higher than that of existing ceramic materials. These features, combined with our experimental design strategy, provide a new insight to design high‐temperature PM filtration materials with durable high performance.

High efficiency hierarchical porous composite microfiltration membrane for high-temperature particulate matter capturing

“…In contrast, the high-temperature PM <2.5 and PM >2.5 separation efficiencies can be enhanced to 91.25% (SD: ± 0.21%) and 99.58% (SD: ± 0.22%) when using PCMM. Furthermore, comparison between our PCMM and various porous materials in previous studies [38][39][40]47,48 shows that our PCMM with a hierarchical micro/nano-dual-scaled pore structural feature exhibits a relatively higher PM >2.5 μm removal efficiency at a much higher pressure (refer to Table 5). It is of note that the upper limit of service temperature of the as-prepared PCMM could be much higher than the testing temperature since PCMM could survive a temperature of up to 900°C.…”

“…6c, d). It is of interest to note that the hierarchical micro/nano-dual-scaled pore structure of porous ceramics was reported to be beneficial to the capturing of high-temperature PM [37][38][39][40] because of the effectively increased contact area between PM and porous structures. However, the reported hierarchical micro/nano-dualscaled porous structures were fabricated by combining chemical grafting of pore-forming agents and polyurethane, which could be easily ablated under high temperature, a potential detriment to practical application 39,40 .…”

Dual-Scale Porosity Alumina Structures Using Ceramic/Camphene Suspensions Containing Polymer Microspheres

“…Porous ceramics can find very useful applications in diverse fields. For example, they can be used as lightweight structural components with high specific strengths and stiffness, scaffolds for bone regeneration [ 1 , 2 , 3 , 4 ], filters [ 5 , 6 , 7 ], thermal insulators [ 8 , 9 ], and electrical components [ 10 , 11 , 12 ]. Fundamentally, the characteristics of porous structures (i.e., porosity, pore size, pore geometry, pore interconnectivity, and pore size distribution) play key roles in the functions of porous ceramics [ 13 ].…”

Ti-40Al-10Nb-10Cr Porous Microfiltration Membrane with Hierarchical Pore Structure for Particulate Matter Capturing from High-Temperature Flue Gas

“…The immense potential in energy conversion and storage, adsorption and separation applications has generated significant interest in the design and synthesis of hierarchically porous materials [1][2][3][4][5]. Hierarchically porous materials have many unique features, such as tunable porous structures, controllable macroscopic morphologies, a large surface area and an easily functionalizable surface, making them some of the most promising engineering structural materials [6][7][8][9][10][11][12][13].…”