Aerogels for Biomedical Applications

The researchers across the world are actively engaged in strategic development of new porous aerogel materials for possible application of these extraordinary materials in the biomedical field. Due to their excellent porosity and established biocompatibility, aerogels are now emerging as viable solutions for drug delivery and other biomedical applications. This chapter aims to cover the diverse aerogel materials used across the globe for different biomedical applications including drug delivery, implantable devices, regenerative medicine encompassing tissue engineering and bone regeneration, and biosensing.

Aerogels as Catalyst Support for Fuel Cells

Environmental pollution caused by the extensive use of fossil fuels and global energy crisis have increased the need to look for renewable energy sources that not only supplement the global energy needs but are economical and environment friendly, thus making way for fuel cells (FCs) as one of the alternatives for replacing the existing fossil fuel based machinery. Nevertheless, there are several factors that account for the hindrance of FCs on a large scale, one of them being the sluggish oxygen reduction reaction (ORR) kinetics taking place at the cathode. Aerogels are a class of promising materials that have the potential to improve the electrocatalytic activity, stability and durability of FCs when used as catalyst support. The present chapter focuses on reporting the latest developments in the field of aerogels as catalyst support for FCs.

Polymer Aerogels: Preparation and Potential for Biomedical Application

Polymeric aerogels have high added value and application. The potential to use natural polysaccharides, especially those from waste, has contributed to adding economic, social and ecological value. This chapter seeks to put forth the latest findings on the development of polymeric aerogels, drying techniques, properties, and pharmacological applications. The functional properties of polymeric aerogels, such as biodegradability, low toxicity and biocompatibility with cellular media are addressed. In the last decade, several works have reported the production of polymeric aerogels from natural polysaccharides. Chemical modifications and filling of new molecules were studied, improving the physicochemical and functional properties of the aerogels, as well as the drying techniques, were reported, and discarded. The production of polymeric aerogels is considered strategic for the development of sustainable, biodegradable and economically viable products.

Aerogels for Insulation Applications

Aerogels have been used as a heat insulating material for the last few decades and possess extremely remarkable qualities for heat insulation. The qualities like light weight (contains more air) and easy to blend with other materials make the aerogel a better insulator than any other material of this kind. The aerogel provides 2 to 3 times better insulation than the styrofoam which is also light weight. The insulating property gets enhanced, if the aerogel is a composite. The interesting details about the insulation property of aerogel will be explored in this chapter.

Aerogels Utilizations in Batteries

Aerogels, a nanoscale 3D mesoporous spongy sample of enhanced surface area, was usually considered as insulator for thermal application, catalyst, and as radiation detector. Presently, it is investigated as potential candidate for electrochemistry due to its inborn capacity to enhance the characteristic features of the surfaces of commercial active materials in batteries and ultracapacitors. Recently composite aerogels which is blended with metal oxides, metal sulphides and so on have been set up as low thickness, profoundly permeable, and large amount of accessible surface and examined as active electrodes. This type of aerogel-based composites challenges the standard manners by that electrochemically active materials are considered, examined, and employed.

Aerogels as Pesticides

Aerogels, composed of complex network of interlinked nanostructures, show 50% non-solid volume. Due to their unique properties, they are used as a carrier for active ingredients used to control agricultural pests as well as veterinary medicines. They can also be used as a carrier material for the application of entomopathogenic bacteria and viruses for the biological control of pests. Many aerogel-based formulations of herbicides, insecticides, acaricides, fungicides, bactericides, rodenticides, nematicides, piscicides and molluscicides effectively control the target pests. Practically, aerogels enhance the effectiveness of insecticides by increasing their penetrations. Furthermore, intensive research is required to develop latest aerogel-based pesticides with better utilization under effective integrated pest management programs in agriculture.

Aerogels Materials for Applications in Thermal Energy Storage

Over the years, aerogel materials reduced thermal conductivity, so proved to be the key method for preventing large consumption of thermal energy. In the class of insulating materials, aerogels have been found, these materials reduce the intermorphosis of heat between ambient sol−gel and various drying methods. Due to Aerogel's tremendous qualities, researchers and engineers showed keen interest in its construction. It showed various characteristics such as nano dimensions, minimum density, narrow, structured, small zero and exposed pore structure, forming through sol components in an arbitrary three-dimensional network. Notable, related to aerogel components, involves storage due to the significant capacity of thermal insulation and its minimum power of operation which means that heat can be stored for a longer period. Due to narrow structural entities, it easily captures light in the meso and nanoporous structure. Aerogels have a greater tendency regarding its heat storing efficacy, creating a simple nature, working consistency other than a commercial insulator. Therefore, this chapter focuses on aerogel's new strategy, which is constantly trending to increase the efficiency of aerogels and improving diverse structurally designed openings, especially insulation effectiveness and low thermal conductivity. Herein, we reviewed the formation of porous aerogels by using carbon nanomaterials, and their corresponding materials comprise GO, rGO, and fabrication with polymer, biomaterial which intrinsically embedded in the aerogel structure to achieve outstanding thermal storage characteristics for higher thermal behavior.

Aerogels for Sensor Application

Aerogels with air-filled pores and interconnected 3D solid networks show unique characteristics and, therefore, have tremendous applications in various fields. Integrating specific characteristics of aerogels, large surface area, low density, and high porosity are included which opens up possibilities for new application areas. Aerogels' advanced features provide high selectivity and sensitivity, fast recovery and response to sensing materials in sensors such as biosensors, gas, pressure, and strain sensors. In recent years significant work has been done regarding the development of aerogel-based sensors. In this chapter, recent challenges and some approaches to high-performance aerogel-based sensor development are summarized.

Bioaerogels: Synthesis Approaches, Biomedical Applications and Cell Uptake

Bioaerogels are a special class of aerogels, produced from natural polymers, are porous structures with promising physicochemical properties for various applications. This chapter focus on the latest bioaerogel findings, addressing the synthesis, impregnation of bioactive compounds, pharmacological applications and aspects of cell uptake, biodegradability and toxicity. Bioaerogels are biomaterials with interesting properties such as high surface area, high thermal and mechanical resistance, low density and dielectric constant. It has been reported that these biomaterials can be used for drug delivery and molecular scaffolding production. Furthermore, it has been shown that bioaerogels are biocompatible, biodegradable, non-toxic, and can be absorbed and degraded by the cellular environment. Finally, bioaerogels are promising, inexpensive, environmentally friendly and versatile materials and can be the basis for the manufacture of new technologies and biomaterials.