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This thesis describes how modifying PDMS can influence the polymer's sorbent properties towards organic compounds in aqueous matrices. Where each new sorbent's extraction performance was measured through TD-GC-MS and characterized through various analytical techniques. Chapter 1: Gives a brief introduction to the analytical techniques used within the thesis whilst outlining the current state-of-the-art PDMS modification techniques reported in recent literature. Chapter 2: Provides the detailed design of experiment and the corresponding materials used for each results chapter. Chapter 3: This chapter shows the results and discussions section for the encapsulation of amines with PDMS. In which each PDMS-based material demonstrated variable sorptive extraction properties towards organic compounds in aqueous solutions compared to PDMS. However, each material presented thermal instability and extraction performance dropped over time. Chapter 4: Highlights how bonding amines to PDMS improved the thermal stability of the sorbent material. However, the TD-GC-MS results showed little variance in extraction performance compared to that of the currently used PDMS, unlike that of the encapsulated method. Chapter 5: This section looked at how a novel preparation technique aimed to incorporate established commercially available sorbents within the PDMS. These bi-phasic sorbents were tested for organic compound extraction via TD-GC-MS. The results showed that the PDMS-Tenax GR outperformed all other sorbents for most of the tested organic compounds. Whilst demonstrating both chemical and thermal robustness. The main issue around this section was how to scale-up the material preparation step. Chapter 6: This chapter provides an overview of the results obtained during the thesis while highlighting the areas of improvement. Future works state the direction this research should move based on the result obtained.

Cellulose-based sorbents are promising materials for wastewater treatment due to their environmental friendliness, biodegradability, and high sorption capacity. This paper presents an overview of cellulose modification methods, including carboxylation, amination, oxidation, graphene, and plasma treatments, as well as combined approaches. Their effect on key physicochemical properties, such as porosity, morphology, and chemical stability, is considered. Examples from the literature confirm the effectiveness of modified cellulose sorbents in removing heavy metal ions and organic pollutants from wastewater. The analysis shows that combined methods allow for creating materials with improved characteristics that are resistant to extreme operating conditions. The main advantages and disadvantages of cellulose sorbents, as well as challenges associated with their scalability and cost-effectiveness, are discussed. The paper emphasizes the importance of further research to advance these materials as a key element of sustainable water treatment technologies.

Hydrogen is a versatile vector for heat and power, mobility, and stationary applications. Steam methane reforming and coal gasification have been, until now, the main technologies for H2 production, and in the shorter term may remain due to the current costs of green H2. To minimize the carbon footprint of these technologies, the capture of CO2 emitted is a priority. The in situ capture of CO2 during the reforming and gasification processes, or even during the syngas upgrade by water–gas shift (WGS) reaction, is especially profitable since it contributes to an additional production of H2. This includes biomass gasification processes, where CO2 capture can also contribute to negative emissions. In the sorption-enhanced processes, the WGS reaction and the CO2 capture occur simultaneously, the selection of suitable CO2 sorbents, i.e., with high activity and stability, being a crucial aspect for their success. This review identifies and describes the solid sorbents with more potential for in situ CO2 capture at high and medium temperatures, i.e., Ca- or alkali-based sorbents, and Mg-based sorbents, respectively. The effects of temperature, steam and pressure on sorbents’ performance and H2 production during the sorption-enhanced processes are discussed, as well as the influence of catalyst–sorbent arrangement, i.e., hybrid/mixed or sequential configuration.

Access to drinkable water is becoming more and more challenging due to worldwide pollution and the cost of water treatments. Water and wastewater treatment by adsorption on solid materials is usually cheap and effective in removing contaminants, yet classical adsorbents are not sustainable because they are derived from fossil fuels, and they can induce secondary pollution. Therefore, biological sorbents made of modern biomass are increasingly studied as promising alternatives. Indeed, such biosorbents utilize biological waste that would otherwise pollute water systems, and they promote the circular economy. Here we review biosorbents, magnetic sorbents, and other cost-effective sorbents with emphasis on preparation methods, adsorbents types, adsorption mechanisms, and regeneration of spent adsorbents. Biosorbents are prepared from a wide range of materials, including wood, bacteria, algae, herbaceous materials, agricultural waste, and animal waste. Commonly removed contaminants comprise dyes, heavy metals, radionuclides, pharmaceuticals, and personal care products. Preparation methods include coprecipitation, thermal decomposition, microwave irradiation, chemical reduction, micro-emulsion, and arc discharge. Adsorbents can be classified into activated carbon, biochar, lignocellulosic waste, clays, zeolites, peat, and humic soils. We detail adsorption isotherms and kinetics. Regeneration methods comprise thermal and chemical regeneration and supercritical fluid desorption. We also discuss exhausted adsorbent management and disposal. We found that agro-waste biosorbents can remove up to 68–100% of dyes, while wooden, herbaceous, bacterial, and marine-based biosorbents can remove up to 55–99% of heavy metals. Animal waste-based biosorbents can remove 1–99% of heavy metals. The average removal efficiency of modified biosorbents is around 90–95%, but some treatments, such as cross-linked beads, may negatively affect their efficiency.

There is considered a method to define parameters for the adsorber with the fixed bed of sorbent. The paper reviews constructional features to clean gas-air mixtures and liquids from toxic contaminants.

Conventional synthetic sorbents for oil spill removal are the most widely applied materials, although they are not the optimal choices from an economic and environmental point of view. The use of inexpensive, abundant, non-toxic, biodegradable, and reusable lignocellulosic materials might be an alternative to conventional sorbents, with obvious positive impact on sustainability and circular economy. The objective of this paper was to review reports on the use of natural-based adsorbing materials for the restoration of water bodies threatened by oil spills. The use of raw and modified natural sorbents as a restoration tool, their sorption capacity, along with the individual results in conditions that have been implemented, were examined in detail. Modification methods for improving the hydrophobicity of natural sorbents were also extensively highlighted. Furthermore, an attempt was made to assess the advantages and limitations of each natural sorbent since one material is unlikely to encompass all potential oil spill scenarios. Finally, an evaluation was conducted in order to outline an integrated approach based on the terms of material–environment–economy.

Solid phase extraction (SPE) is an analytical procedure developed with the purpose of separating a target analyte from a complex sample matrix prior to quantitative or qualitative determination. The purpose of such treatment is twofold: elimination of matrix constituents that could interfere with the detection process or even damage analytical equipment as well as enriching the analyte in the sample so that it is readily available for detection. Dispersive solid phase extraction (dSPE) is a recent development of the standard SPE technique that is attracting growing attention due to its remarkable simplicity, short extraction time and low requirement for solvent expenditure, accompanied by high effectiveness and wide applicability. This review aims to thoroughly survey recently conducted analytical studies focusing on methods utilizing novel, interesting nanomaterials as dSPE sorbents, as well as known materials that have been only recently successfully applied in dSPE techniques, and evaluate their performance and suitability based on comparison with previously reported analytical procedures.

Aerogel fibers have been recognized as the rising star in the fields of thermal insulation and wearable textiles. Yet, the lack of functionalization in aerogel fibers limits their applications. Herein, we report hygroscopic holey graphene aerogel fibers (LiCl@HGAFs) with integrated functionalities of highly efficient moisture capture, heat allocation, and microwave absorption. LiCl@HGAFs realize the water sorption capacity over 4.15 g g −1 , due to the high surface area and high water uptake kinetics. Moreover, the sorbent can be regenerated through both photo-thermal and electro-thermal approaches. Along with the water sorption and desorption, LiCl@HGAFs experience an efficient heat transfer process, with a heat storage capacity of 6.93 kJ g −1 . The coefficient of performance in the heating and cooling mode can reach 1.72 and 0.70, respectively. Notably, with the entrapped water, LiCl@HGAFs exhibit broad microwave absorption with a bandwidth of 9.69 GHz, good impedance matching, and a high attenuation constant of 585. In light of these findings, the multifunctional LiCl@HGAFs open an avenue for applications in water harvest, heat allocation, and microwave absorption. This strategy also suggests the possibility to functionalize aerogel fibers towards even broader applications. Functionalization of aerogel fibers, characterized by high porosity and low thermal conductivity, to obtain multifunctional materials is highly desirable. Here the authors report hygroscopic holey graphene aerogel fibers hosting LiCl salt, enabling moisture capture, heat allocation, and microwave absorption performance.

There are a lot of review papers of sample pretreatment, but the comprehensive review on pipette-tip solid-phase extraction (PT-SPE) is lacking. This review (133 references) is mainly devoted to the development of different types of micro- and nanosorbent-based PT-SPE, including silica materials, carbon materials, organic polymers, molecularly imprinted polymers, and metal-organic frameworks. Each section mainly introduces and discusses the preparation methods, advantages and limitations of adsorbents, and their applications to environmental, biological, and food samples. This review also demonstrates the advantages of PT-SPE like convenience, speed, less organic solvent, and low cost. Finally, the future application and development trend of PT-SPE are prospected. Graphical abstract