Fabrication and characterization of a novel konjac glucomannan-based air filtration aerogels strengthened by wheat straw and okara

Abstract

The konjac glucomannan (KGM)-based aerogel as an air filtration material was fabricated through sol-gel and freeze-drying methods. Results showed that gelatin and starch addition could increase the filtration efficiency and compressive strength of aerogel significantly, due to the appearance of more microporous structure and the formation of dense structure in aerogel. The addition of wheat straw could decrease the filtration resistance and increase the breathability of KGM-based aerogel, which was attributed to the multi-cavities of wheat straw. The aerogel with wheat straw had a filtration efficiency of 93.54% for particle matters ≥ 0.3 μm, a filtration resistance 29 Pa, and an air permeability 271.42 L/s•m2. Okara addition could increase the hydrophobicity of KGM-based aerogel by increasing the water contact angle and decreasing the equilibrium water content. The water contact angle of the aerogel containing okara reached 105.4°, and the equilibrium water content was decreased by 17.03%-81.10% compared with that without okara, with relative humidity 0%-80%. The results demonstrated that the KGMbased aerogel had good performance on filtration, mechanical and hydrophobic properties, indicating high potential application as an air filtration material.

Multistructured Electrospun Nanofibers for Air Filtration: A Review

“…Many studies have optimized its performance by adjusting spinning solution concentration, applied voltage, spinning time, and environmental conditions (humidity or temperature). , However, the effect of conventional strategies on improving filtration performance is not significant. It is worth noting that multistructured membranes such as nanofiber/network structure, cavity structure, multilayer structure and patterned structure based on smooth fiber has been proved to be the most effective for the improvement the value of QF. Researchers tend to focus on improving air filtration efficiency by adjusting the thickness of nanofibers, while ignoring the more effective way to adjust the surface structure of nanofibers.…”

The advances of polysaccharide-based aerogels: Preparation and potential application

“…First, gel sol is frozen, and then the ice of gel is sublimated during which the liquid in gels is replaced by gas to generate pores under high vacuum. (Ni, et al, 2016;Wang, et al, 2019). Aerogel structure is determined by ice crystal growth process of the gel solution.…”

Polymer Aerogels: Preparation and Potential for Biomedical Application

“…Aerogel has advantages over other materials because the pores can be designed according to the purpose of the aerogels application. The porous channels of polymeric aerogels are advantageous due to the pore quality, size, thickness and low density of the polymer associated with the aerogels, which contribute to define the type of application [36].…”

“…However, in cases where aerogels are applied as pollutant adsorbents, a mix of close and open pores is advisable. Therefore, the requirement of structuring defined pore-polymeric air-synthesis synthesis projects is strategic to meet application requirements [36].…”