Exploring the Versatility of Aerogels: Broad Applications in Biomedical Engineering, Astronautics, Energy Storage, Biosensing, and Current Progress

Machine learning predictions of drug release from isocyanate-derived aerogels

This work utilized machine learning (ML) algorithms to predict and validate the in vitro drug release kinetics of a short worm-like nanostructured isocyanate-derived aerogel: the first time ML has been employed to study the drug delivery properties of this important class of materials. The algorithms were first trained with sixteen datasets, each containing eight release data points, before using them to predict the release profiles of the unknown. The predicted data was validated via the random sampling and cross-validation techniques. In both instances, the established models were used to predict the release kinetics of four aerogel nanostructures with known experimental release profiles. A good correlation between the experimental and predicted release profiles was observed, with gradient boosting being the best-performing algorithm (R2 > 0.9). Furthermore, the ranking of the importance of each input feature for drug release from the aerogels aligns with previous studies, validating the rationale behind the modeling. Morphology, quantified by the K-index (contact angle/porosity), and the macropore-to-mesopore ratios were found to be the most influential factors, after time, in determining drug release profiles. The findings from this study suggest that ML can serve as a valuable tool for predicting the drug release kinetics of aerogels, thereby saving time and cost involved in conducting laborious drug delivery experiments. We envisage that this study will provide a foundation for future related computational works and reduce the trial-and-error experimental approach to solving scientific problems.

Optimization of 3D Metal-Based Assemblies for Efficient Electrocatalysis: Structural and Mechanistic Studies

The commercial utilization of low-dimensional catalysts has been hindered by their propensity for agglomeration and stacking, greatly minimizing their utilization of active sites. To circumvent this problem, low-dimensional materials can be assembled into systematic 3D architectures to synergistically retain the benefits of their constituent low-dimensional nanomaterials, with value-added bulk properties such as increased active surface area, improved charge transport pathways, and enhanced mass transfer, leading to higher catalytic activity and durability compared to their constituents. The hierarchical organization of low-dimensional building blocks within 3D structures also enables precise control over the catalyst's morphology, composition, and surface chemistry, facilitating tailored design for specific electrochemical applications. Despite the surge in 3D metal-based assemblies, there are no reviews encompassing the different types of metal-based 3D assemblies from low-dimensional nanomaterials for electrocatalysis. Herein, this review addresses this gap by investigating the various types of self-supported 3D assemblies and exploring how their electrocatalytic performance can be elevated through structural modifications and mechanistic studies to tailor them for various electrochemical reactions.

Silica Aerogels as a Promising Vehicle for Effective Water Splitting for Hydrogen Production

This comprehensive review explores silica aerogels and their application in environmental remediation. Due to rapid growth in the consumption of energy and water resources, the purification of contaminated resources for use by humankind should be considered important. The primary objectives of this review are to assess the evolving landscape of silica aerogels, their preparation, and drying techniques, and to discuss the main findings from a wide range of empirical studies and theoretical perspectives. Based on a significant amount of research, this review provides information about aerogels' capabilities as an adsorbent and catalyst. The analysis spans a variety of contexts for the generation of hydrogen and the degradation of the dyes employed in industry, showing better performance in environmental remediation. The implications of this review point to the need for well-informed policies, innovative synthesis strategies, and ongoing research to harness the full potential for environmental management.

Cellulose Nanofiber-Reinforced γ-AlOOH Aerogels for Enhanced Removal of Environmental Pollutants

In this study, we report the modification of a monolithic γ-aluminum oxy-hydroxide (γ-AlOOH) aerogel with cellulose nanofibers (CNFs) using the sol-gel method via supercritical drying. The optimized 2% CNF (w/w) results in a monolithic CNF-γ-AlOOH that is amorphous in nature, along with C-C and C-O-C functional groups. Transmission electron microscopy (TEM) images of the as-synthesized CNF-γ-AlOOH showed CNF embedded in the γ-AlOOH aerogel. The adsorption capacities were determined using azo dyes: methylene blue (MB) and crystal violet (CV), and heavy metal ions: lead [Pb(II)], uranium [U(VI)], and arsenic [As(III)] as models for environmental pollutants. The maximum adsorption capacities were 210 mg/g for CV, 204 mg/g for MB, 105 mg/g for As(III), and 339 mg/g for U(VI) at a pH of 7, whereas Pb(II) exhibited a maximum adsorption capacity of 100 mg/g at pH 5. This is attributed to the synergistic interactions between the CNF hydroxyl groups and γ-AlOOH active sites, facilitating electrostatic and coordination interactions. The as-synthesized aerogels demonstrated high recyclability, retaining over 94% adsorption efficiency after five cycles and offering a sustainable approach to environmental remediation. These findings establish CNF-γ-AlOOH aerogels as robust, eco-friendly materials for water treatment applications, with potential scalability for addressing diverse environmental pollutants. Future research should explore their application in the removal of emerging contaminants and optimize their synthesis for household and industrial-scale implementation.

Study on properties and simulation application scenarios of flame retarded modified konjac glucomannan organic and inorganic composite aerogel

In this paper, a new organic-inorganic biomass composite aerogel was prepared by freeze-drying method with glucomannan, hydrophilic isocyanate, water-soluble flame retardant, and water glass as raw materials. Biomass Konjac glucose mannan (KGM) was used as the main network framework, KGM was chemically cross-linked and alkali-cross-linked with hydrophilic isocyanate and Na2SiO3 solution, and flame retardant modified with water-soluble flame retardant and water glass. The microstructure showed an obvious organic-inorganic interpenetrating network structure. The compressive strength of sample K2S4P2 was 4.751 ± 0.089 MPa, and the compression modulus of sample K2S4P1B modified by boric acid hydrolysis of Na2SiO3 was 63.76 ± 1.81 × 103 m2/s2. The introduction of boron ions contributes to the thermal stability of organic components. The peak and total heat release rates of sample K2S4P1A4 decreased by 80.3 % and 50.8 %, respectively. In addition, the thermal simulation calculation of the external wall in winter and summer using ANSYS software showed that the thickness of the insulation layer with the best insulation effect is 40-60 mm. The organic-inorganic composite aerogel provides a simple and environmentally friendly method for the application of external wall insulation systems in low-energy buildings with both mechanical properties and flame retardant properties.

Harmonizing Innovations: An In-Depth Comparative Review on the Formulation, Applications, and Future Perspectives of Aerogels and Hydrogels in Pharmaceutical Sciences

Gels, specifically hydrogels and aerogels, have emerged as versatile materials with profound implications in pharmaceutical sciences. This comprehensive review looks into detail at hydrogels and aerogels, providing a general introduction to gels as a foundation. The paper is then divided into distinct sections for hydrogels and aerogels, each delving into their unique formulations, advantages, disadvantages, and applications. In the realm of hydrogels, we scrutinize the intricacies of formulation, highlighting the versatile advantages they offer. Conversely, potential limitations are explored, paving the way for a detailed discussion on their applications, with a specific focus on their role in antimicrobial applications. Shifting focus to aerogels, a thorough overview is presented, followed by a detailed explanation of the complex formulation process involving sol-gel chemistry; aging; solvent exchange; and drying techniques, including freeze drying, supercritical drying, and ambient-pressure drying (APD). The intricacies of drug loading and release from aerogels are addressed, providing insights into their pharmaceutical potential. The advantages and disadvantages of aerogels are examined, accompanied by an exploration of their applications, with a specific emphasis on antimicrobial uses. The review culminates in a comparative analysis, juxtaposing the advantages and disadvantages of hydrogels and aerogels. Furthermore, the current research and development trends in the applications of these gels in pharmaceutical sciences are discussed, providing a holistic view of their potential and impact. This review serves as a comprehensive guide for researchers, practitioners, and enthusiasts, seeking a deeper understanding of the distinctive attributes and applications of hydrogels and aerogels in the ever-evolving research concerning pharmaceutical sciences.

Advancements in Aerogel Technology for Antimicrobial Therapy: A Review

This paper explores the latest advancements in aerogel technology for antimicrobial therapy, revealing their interesting capacity that could improve the current medical approaches for antimicrobial treatments. Aerogels are attractive matrices because they can have an antimicrobial effect on their own, but they can also provide efficient delivery of antimicrobial compounds. Their interesting properties, such as high porosity, ultra-lightweight, and large surface area, make them suitable for such applications. The fundamentals of aerogels and mechanisms of action are discussed. The paper also highlights aerogels' importance in addressing current pressing challenges related to infection management, like the limited drug delivery alternatives and growing resistance to antimicrobial agents. It also covers the potential applications of aerogels in antimicrobial therapy and their possible limitations.

Nanotechnology-enhanced fiber-reinforced polymer composites: Recent advancements on processing techniques and applications

Incorporating nanoparticles can significantly improve the performance and functionality of fiber-reinforced polymer (FRP) composites. Different techniques exist for processing, testing, and implementing nanocomposites in various industries. Depending on these factors, these materials can be tailored to suit the specific applications of the automotive and aerospace industries, defence industries, biomedical and energy sectors etc. Nanotechnology offers several potential benefits for composites, including improved mechanical properties, surface modification, and sensing capabilities. This paper discusses the different types of nanoparticles, nanofibers, and nano-coating that can be used for reinforcement, surface modification, and property enhancement in FRP composites. It also examines the challenges associated with incorporating nanotechnology into composites and provides recommendations for potential opportunities in future work. This study is intended to offer a comprehensive understanding of the current research on using nanotechnology in FRP composites and its potential impact on the composites industry.