Method For Preparation Of Composites Research Articles

One-step synthesis of a novel natural mineral-derived Fe@BC for enhancing Cr(VI) bioreduction: Synergistic role of electron transfer and microbial metabolism

Iron minerals, which exert excellent biocompatibility and reactivity with redox-active microorganisms, have attracted attention as a precursor to synthesizing composite materials with higher catalytic efficiency in driving redox-active microorganisms to reduce Cr(VI). However, researches on the effective preparation method of composites, the interaction between bacteria and composite materials and the mechanism of electron transfer are still scarce. In this work, Fe-complex@BC prepared by a one-step method using goethite was used for chromium treatment together with soil microorganisms. The composite was the best-performing in promoting Cr(VI) bioreduction (up to 3.48 mg (L·h)−1) than Fe-complex (2.26 mg (L·h)−1) and biochar (0.5 mg (L·h)−1), even about 19 times higher than that of bioreduction without materials. Specifically, Fe-complex@BC shortened the electron transfer distance due to its excellent adsorption properties for bacteria and Cr(VI). Its high redox activity also promoted Cr(VI) bioreduction by directly enhancing electron transfer. In addition, the presence of the Fe(III)/Fe(II) cycle proved that the active sites of composite could be regenerated to reduce Cr(VI) persistently by receiving extracellular electrons from bacteria. High-throughput 16 S rDNA gene sequencing indicated the composite could promote the proliferation of electrochemically active bacteria, which directly enhanced bioreduction. This study developed the low-cost Fe@BC material prepared by a one-step co-pyrolysis method, which exerts a synergistic effect with soil microorganisms and presents a promising potential for chromium pollution treatment.

Strengthening‐toughening of graphene nanoplates and in situ ZrB2 nanoparticles reinforced AA6111 matrix composites with discontinuous layered structures

Simultaneously achieving high strength and ductility is a critical issue for graphene nanoplates (GNPs) reinforced aluminum matrix composites. Layered structures and in situ nanoparticles were applied to achieve the strengthening and toughening of GNPs reinforced aluminum matrix composites from the structure and composition design, respectively. Therefore, the discontinuous layered AA6111 matrix composites synergistically reinforced with GNPs and in situ ZrB2 nanoparticles were prepared by the composite melt preparation method and hot rolling. The discontinuous layered structure features of graphene, particles, and matrix were investigated. The interfaces between reinforcements and the matrix were further characterized by high-resolution transmission electron microscopy. It was found that the improved load transfer efficiency of GNPs was mainly attributed to the formation of a high-strength amorphous alumina interface between GNPs and the aluminum, as well as the pinning effect of the Al2Cu particles on GNPs' surface. By analyzing characteristics of the dislocation configuration, GNPs and nanoparticles boosted the dislocation storage capacity of the composite, while the particles dispersed the stress concentration at the edge tip of GNPs, thereby improved the composite's ductility. The composite achieved a 50% (349 MPa) increase in yield strength with only a 30% compromise on ductility (13.8%), leading to a notable improvement in toughness. The research revealed an efficient way for manufacturing high strength-ductility metal matrix composites with discontinuous layered structures via well-bonded interfaces employing GNPs and nanoparticles.

Research on polyamide based self‐lubricating composites: A review

AbstractOwing to its good tribological and mechanical properties, polyamide material was widely applied to prepare sliding mechanical parts. A lot of studies confirmed that adding different functional materials or surface modifications to polyamide could reduce the friction coefficient, improve wear resistance and reduce water absorption, so as to prolong the service life of polyamide parts. This paper summarized the common reinforcement methods of polyamide materials: blending, surface modification and filler. The reinforcing mechanism of different fillers and polymers, the effects of different methods on the tribological properties, mechanical properties and water absorption of polyamide composites, and the preparation methods of polyamide composites have been systematically discussed.

Polybutylene succinate (PBS)/natural fiber green composites: melt blending processes and tensile properties

Abstract An increase in the environmental consciousness at present has enhanced the awareness of researchers in utilizing biodegradable materials for the production of environmentally friendly products. Currently, biodegradable polymers, for example, polylactic acid, polybutylene succinate, polycaprolactone, etc., can be utilized as matrices to produce green composites. Meanwhile, natural fibers have been used as fillers for green composites as they are biodegradable and renewable. In this brief review, the physicochemical properties of selected biodegradable polymer, specifically polybutylene succinate, are demonstrated. Moreover, examples of natural fibers that are usually used to produce green composites are also shown. Additionally, practical methods employed for the preparation of green composites were exposed. The tensile properties of green composites, such as the tensile strength, tensile modulus, and elongation at break at different loadings of natural fibers, are also briefly reviewed. The information obtained in this review provides detailed differences in the preparation methods of green composites. In addition, this brief review supplies a clearer comprehension of the tensile properties of green composites for the usage of semistructural and packaging applications.

The effect of bonding method between WC-Cr3C2–Ni and multiwall carbon nanotubes powders on the properties of composite coatings

The WC-20Cr3C2–7Ni/multiwall carbon nanotubes (WCN/MWCNTs) composite powders were prepared by mechanical bonding and surface modification, respectively. In the process of mechanical bonding method (M1), the dispersion of MWCNTs and maintained structural of composite powder (WCN1) were achieved by slurry-based dispersion. On the basis of the M1, a novel, simple and environment-friendly composite powder preparation method was proposed (M2). The surface of the composite powder (WCN2) was modified, leading to the transformation of interfacial bonding between WCN and MWCNTs from mechanical bonding to mechanical bonding accompanied by hydrogen bonding. The distribution of MWCNTs on the surface of WCN2 powder was more uniform than that of WCN1 power. The coatings (WCN, WCN1, WCN2) were prepared by high-velocity oxygen-fuel (HVOF) spraying. Compared with the WCN coating, the homogeneous distribution of MWCNTs not only increased the hardness, elastic modulus and corrosion resistance of the WCN2 coating, but also decreased the brittleness of the WCN2 coating.

Low-energy-consumption fabrication of porous TPU/graphene composites for high-performance microwave absorption and the influence of Fe3O4 incorporation

Fabrication of lightweight, thin thickness, broad bandwidth, strong absorption, and lower filler loading materials are of great interest for microwave absorption. Herein, porous thermoplastic polyurethane (TPU) /graphene composites were successfully prepared via a facile vapor induced phase separation (VIPS) technique. Compared with TPU foam, the introduction of graphene endows the composites favorable microwave absorption ability. The optimized composite foam with 3 wt% graphene (TPU/G-3) exhibits extraordinary wave attenuation capacity with a minimum reflection loss (RL min ) value of − 51.86 dB and effective absorption bandwidth (EAB) of 4.28 dB (12.6–17.0 GHz) at the thickness of 3.1 mm. Microwave attenuation mechanism indicates that the remarkable microwave absorption ability derives from conduction loss, dipole polarization loss, interfacial polarization loss as well as multiple scattering. Incorporating the same amount of Fe 3 O 4 as graphene to TPU/G-3 endows the composites with the RL min of − 58.96 dB, which is slightly better than TPU/G-3 due to more favorable impedance matching. However, the matching thickness becomes much higher to about 8.0 mm, which is mainly attributed to bigger pores caused by Fe 3 O 4 . Moreover, the VIPS strategy provides insight into the fabrication of facile and lightweight polymer-based porous electromagnetic absorption materials. • Vapor induced phase separation method for preparation of TPU-based porous composites. • Graphene facilitates heterogeneous nucleation for smaller pores than TPU foam. • Graphene content of 3 wt% endows composite favorable microwave absorbing performance. • Fe 3 O 4 influences the process of vapor induced phase separation with bigger pores. • Fe 3 O 4 improves the reflection loss but increases matching thickness due to big pores.

Preparation and Hydrophobicity of Bionic Structures Based on Composite Infiltration Model.

The wettability, surface energy, structure, and morphology of a material’s surface will affect the interaction process between the material and the organism. Moreover, these factors are not independent of each other, but will affect each other, which together determine the biological surface of the material. Although two classic theories of surface wettability control have been established, including the Wenzel model and the Cassie–Baxter model, the mechanism of the microstructure parameters on the surface wettability has not been considered. This paper established a two-dimensional mathematical model of the composite wetting pattern based on microstructure parameters, revealed the mechanism of the microstructure parameters on the surface wettability, and then used ultra-precision cutting and molding composite preparation methods to quickly and efficiently prepare bionic structures, and the hydrophobic character of the microstructure was characterized by the contact angle meter, which provides theoretical support and preparation technology for the modification of the hydrophobic character of the material.

Growing Bacterial Cellulose-Based Sustainable Functional Bulk Nanocomposites by Biosynthesis: Recent Advances and Perspectives

ConspectusIn recent years, with the continuous development of nanomaterials and composite preparation methods, nanocomposites are playing an increasingly important role as structural materials or functional materials due to their outstanding properties. As an important part of nanocomposites, polymer-based nanocomposites have attracted the interest of researchers, whose preparation methods have been significantly expanded with the rapid development of polymer chemistry and physics. At present, nanomaterials can be combined with the polymer matrix to form various nanocomposite materials in multiple ways, ranging from simple blending to complex processes combining surface modification and in situ polymerization. However, these polymer-based nanocomposites are still limited by their incompatibility of structural strength and functionality and unsustainability of the preparation processes.As a new type of polymer-based materials, the polymers synthesized by microorganisms, especially bacterial cellulose (BC) produced by bacteria such as Gluconacetobacter xylinus, have great potential to overcome the above-mentioned problems. On the one hand, BC has a fine nanoscale three-dimensional (3D) network with extremely high strength. The continuous nanoscale 3D network means that the nanomaterials composited with BC can be interspersed in a 3D network, effectively exerting their functionality without compromising the strength of the composites. On the other hand, the process of microbial production of BC is completed under normal pressure and temperature without using toxic reagents and solvents, which gives it a huge advantage in terms of sustainability over traditional polymer synthesis. Unfortunately, the high-density 3D nanoscale network of BC is too tight to allow the entry of nanomaterials in a homogeneous way, which brings great difficulties to the composite process of BC and nanomaterials.Challenging this problem, a new in situ composite preparation strategy called aerosol-assisted biosynthesis (AABS) strategy has been proposed as a solution. This strategy cleverly combines the deposition of nanomaterial-contained aerosol and microbial synthesis of BC, leading to uniform dispersion of various nanomaterials in the BC network and the formation of nanocomposites. In this Account, we review the development history of composite preparation methods and discuss its trend from the perspective of matching of its critical factors in dimensions of space and time. From the view of the spatiotemporal overlap of the factors, we analyze how this AABS strategy combines the BC synthesis process and the composite formation in the dimensions of space and time, resulting in the universality, tunability, designability, scalability, sustainability, and other advantages of the AABS strategy. Furthermore, we look forward to the future where AABS-based composite preparation systems can be combined with artificial intelligence and automation systems to realize fully automatic and sustainable biointelligent fabrication.

A novel method for fabrication of a binary oxide biochar composite for oxidative adsorption of arsenite: Characterization, adsorption mechanism and mass transfer modeling

Arsenite [As(III)] is more mobile and toxic than arsenate [As(V)], making it more difficult and more critical to remove from water. The oxidative adsorption of As(III) is preferred due to its cost and time effectiveness. The chemical mixing process is a common method for preparation of biochar composites, but it is not time-efficient for homogeneous metal impregnation and is challenging to achieve consistent and reproducible physicochemical properties of the composite. The mixing method is even more challenging if two metal oxides are utilized in preparing engineered biochars. The current study proposes a novel microwave- and electrochemical-assisted technique to overcome the shortcomings of the mixing method and create a binary-oxide biochar composite with oxidation and adsorption capabilities. In addition, a new procedure was used to develop a diffusional mass transfer model combined with a genetic algorithm to characterize the adsorption process. Characterization of the fabricated biochar indicated that the deposited Fe and Mn oxides on the biochar surface included a mixture of Mn(II,III,IV) oxides and poorly crystalline α-FeOOH, respectively. The adsorption results suggested a hybrid adsorption mechanism with a high probability of a homogeneous monolayer adsorption process. Based on XANES analyses, no reduction to As(III) was observed for the As(V) adsorbed onto adsorbent, while 79% of the adsorbed As(III) was oxidized to As(V). The intraparticle diffusion and external mass transfer coefficients were estimated using a diffusional mass transfer model. Based on the modeling results, the adsorption of As onto the fabricated adsorbent was mainly controlled by external mass transfer. Overall the As(III) adsorption capacity of untreated biomass increased from 62 to 21,426 μg/g through the modification, indicating the high potential of the proposed procedure for preparation of adsorbents with improved oxidation and adsorption performance.

Reactive Cellu-mers-A Novel Approach to Improved Cellulose/Polymer Composites.

In this paper, we describe a novel method for preparation of polymer composites with homogeneous dispersion of natural fibers in the polymer matrix. In our approach, Williamson ether synthesis is used to chemically modify cellulose with polymerizable styrene moieties and transform it into a novel multifunctional cellu-mer that can be further crosslinked by copolymerization with styrene. Reactions with model compounds (cellobiose and cellotriose) successfully confirm the viability of the new strategy. The same approach is used to transform commercially available cellulose nanofibrils (CNFs) of various sizes: Sigmacell and Technocell™ 40, 90 and 150. The styrene-functionalized cellulose oligomers and CNFs are then mixed with styrene and copolymerized in bulk at 65 °C with 2,2′-azobisisobutyronitrile as initiator. The resulting composites are in a form of semi-interpenetrating networks (s-IPN), where poly(styrene) chains are either crosslinked with the uniformly dispersed cellulosic component or entangled through the network. Non-crosslinked poly(styrene) (31–41 w%) is extracted with CHCl3 and analyzed by size-exclusion chromatography to estimate the extent of homopolymerization and reveal the mechanism of the whole process. Electron microscopy analyses of the networks show the lack of cellu-mer agglomeration throughout the polymer matrix. The homogeneous distribution of cellulose entities leads to improved thermal and mechanical properties of the poly(styrene) composites compared to the physical mixtures of the same components and linear poly(styrene) of similar molecular mass.

Microstructure evolution and the mechanical properties of in-situ Ti2AlCw-NbC@TiBx/TiAlNb composite with high performance

This manuscript reports an innovative preparation method of TiAl matrix composites. The mixed AlNb powder and B4C powder were put into TiAlNb alloy melt after ball milling. With the help of the reaction in AlNb/B4C powders and the in-situ reaction of various elements in TiAlNb alloy melt, hybrid Ti2AlCw and [email protected] core-shell structure with high dispersion and good interface bonding were synthesized and introduced into TiAlNb alloy. The analysis shows that the NbC/TiBX of the core-shell structure was based on the in-situ reaction on the NbC substrate obtained in high-energy ball milling and was formed by the in situ reaction in the TiAlNb melt. The [email protected] structure and the in-situ Ti2AlC whiskers both have excellent interfacial bonding with TiAl matrix. In this TiAlNb composite with dual-scale reinforcements, the combination of multiple strengthening/toughening mechanisms improves the mechanical properties of TiAlNb alloy matrix. The in-situ Ti2AlCw and [email protected] hybrid reinforced TiAlNb composite was prepared successfully. Room compression tests show that the fracture stress and strain of the composite are increased from 1548 MPa, 20.6% to 2678 MPa, 29.1%. And the high temperature compression tests (at 1073 K) show that the fracture stress and strain of the alloy are increased from 641 MPa, 23.4% to 1012 MPa, 35.9%.

Hydrothermal synthesis of MXene-MoS2 composites for highly efficient removal of pesticides

Ti3C2 is regarded as the most popular MXene, which has been extensively investigated as a candidate for fabrication of adsorbents to remove environmental pollutants. However, the adsorption capacity of unmodified MXene is limited owing to the lack of specific adsorption sites. In this work, we reported a simple hydrothermal method for preparation of Ti3C2-MoS2 composites and examined their adsorption removal of organic pesticide paraquat (PQ) for the first time. The adsorption equilibrium will reach within 30 min and the adsorption capacity was increased from 8.7 mg/g to 105.53 mg/g as compared with that of Ti3C2. The adsorption process is more inclined to follow the Freundlich isotherm model and quasi-second-order kinetic model, which points to that the adsorption process is multilayer adsorption and may followed both physical adsorption and chemical adsorption. Adsorption of PQ on Ti3C2-MoS2 is a spontaneous exothermic process and many factors, such as temperature, pH values, and ion strength can influence the adsorption performance. The obvious increase of adsorption performance of Ti3C2-MoS2 might be ascribed to the increase of specific surface area after the introduction of flower-like MoS2. More than that, PQ also might be catalytically degraded by Ti3C2-MoS2 for its semiconductor property.

Metallic Copper-Containing Composite Photocatalysts: Fundamental, Materials Design, and Photoredox Applications.

Semiconductor photocatalysis has long been regarded as a potential solution to tackle the energy and environmental challenges since the first discovery of water splitting by TiO2 almost 50 years ago. The past few years have seen a tremendous flurry of research interest in the modification of semiconductors because of their shortcomings in the aspects of solar harvesting, electron-hole pairs separation, and utilization of photogenerated carriers. Among the various strategies, the introduction of metallic copper into the photocatalysis system can not only enhance the absorption of sunlight and the separation efficiency of photogenerated electrons and holes, but also increase the adsorption ability of substrate and the number of active sites, so as to realize the high solar to chemical energy conversion efficiency. This review focuses on the rational design of copper-based composites and their applications in photoredox catalysis. First, the preparation methods of metallic copper-containing composites are discussed. Then, the applications of different types of copper-based composites in the photocatalytic removal of pollutants, splitting of water to hydrogen production, reduction of carbon dioxide, and conversion of organic matter are introduced. Finally, the opportunities and challenges in the design and synthesis of copper-based composites and their applications in the photocatalysis are prospected.

Cellulosic biomass-based sustainable hydrogels for wastewater remediation: Chemistry and prospective

Despite several technological improvements and achievements, wastewater treatment remains a serious issue internationally. Toxins in wastewater pose a significant threat to human health if left untreated. Due to macro-porous structure and different surface functionalization, cellulose biomass-based hydrogel is the most traditional adsorbent for removing harmful ions from wastewater. Recently, the introduction of several new cellulose derived materials have demonstrated their competitiveness in the removal of harmful ions. Numerous exceptional qualities better define this promising material, including high mechanical strength, large surface area and chemical inertness. This paper discusses the development status, preparation and modification methods of cellulose composites created by various materials (graphene, fly ash, graphene oxide and bentonite) which evaluates the research development and existing challenges in water treatment.

Preparation and Machine-Learning Methods of Nacre-like Composites from the Self-Assembly of Magnetic Colloids Exposed to Rotating Magnetic Fields.

Composite materials designed by nature, such as nacre, can display unique mechanical properties and have therefore been often mimicked by scientists. In this work, we prepared composite materials mimicking the nacre structure in two steps. First, we synthesized a silica gel skeleton with a layered structure using a bottom-up approach by modifying a sol-gel synthesis. Magnetic colloids were added to the sol solution, and a rotating magnetic field was applied during the sol-gel transition. When exposed to a rotating magnetic field, magnetic colloids organize in layers parallel to the plane of rotation of the field and template the growing silica phase, resulting in a layered anisotropic silica network mimicking the nacre's inorganic phase. Heat treatment has been applied to further harden the silica monoliths. The final nacre-inspired composite is created by filling the porous structure with a monomer, leading to a soft elastomer upon polymerization. Compression tests of the platelet-structured composite show that the mechanical properties of the nacre-like composite material far exceed those of nonstructured composite materials with an identical chemical composition. Increased toughness and a nearly 10-fold increase in Young's modulus were achieved. The natural brittleness and low elastic deformation of silica monoliths could be overcome by mimicking the natural architecture of nacre. Pattern recognition obtained with a classification of machine learning algorithms was applied to achieve a better understanding of the physical and chemical parameters that have the highest impact on the mechanical properties of the monoliths. Multivariate statistical analysis was performed to show that the structural control and the heat treatment have a very strong influence on the mechanical properties of the monoliths.

Metal-organic Framework (MOF) Composites for Photodegradation of Hazardous Organic Materials

Photocatalytic degradation is an energy efficient, cost-effective, and stable process that has a wide-range of application. It is considered as a promising method for the removal of organic pollutants. As a new type of porous material, Metal-organic framework (MOF) composites have been proven to be an ideal catalyst for the degradation of organic pollutants due to their small size and large specific surface area. In this review, several common preparation methods of MOF composites are evaluated: microwave synthesis, solvent-thermal method, electrochemical method and layer by layer growth method. The degradation effects of MOF composites on different organic pollutants are summarized, and the excellent photocatalytic performances of some MOF composites are demonstrated. Finally, the prospects of photocatalytic degradation of organic pollutants by MOF composites are examined, and the challenges in further development of MOF composites are discussed.

Current State and Challenges of Natural Fibre-Reinforced Polymer Composites as Feeder in FDM-Based 3D Printing.

As one of the fastest-growing additive manufacturing (AM) technologies, fused deposition modelling (FDM) shows great potential in printing natural fibre-reinforced composites (NFRC). However, several challenges, such as low mechanical properties and difficulty in printing, need to be overcome. Therefore, the effort to improve the NFRC for use in AM has been accelerating in recent years. This review attempts to summarise the current approaches of using NFRC as a feeder for AM. The effects of fibre treatments, composite preparation methods and addition of compatibilizer agents were analysed and discussed. Additionally, current methods of producing feeders from NFRCs were reviewed and discussed. Mechanical property of printed part was also dependent on the printing parameters, and thus the effects of printing temperature, layer height, infill and raster angle were discussed, and the best parameters reported by other researchers were identified. Following that, an overview of the mechanical properties of these composites as reported by various researchers was provided. Next, the use of optimisation techniques for NFRCs was discussed and analysed. Lastly, the review provided a critical discussion on the overall topic, identified all research gaps present in the use of NFRC for AM processes, and to overcome future challenges.

Review on improvement of adsorption refrigeration systems performance using composite adsorbent: current state of art

ABSTRACT As adsorption refrigeration systems are powered by waste heat from automobile/industries and run by environment-friendly refrigerants, they have very promising cooling technology compared to vapor compression and absorption cooling systems. But due to large size, less performance and high installation cost, adsorption cooling systems have not yet been commercially popular. Literature review shows the physical adsorbent has poor adsorption capacity as compared to the chemical adsorbent. However, the salt swelling and agglomeration are the phenomenal challenges associated with chemical adsorption systems leading to reduction in the heat and mass transfer performances. To overcome the demerits of the physical and the chemical adsorbents, composite adsorbent systems have been developed to harness the potentiality of the adsorption capacity and increase the heat and mass transfer performances of adsorbent. In the present work the performance of different adsorption refrigeration system working on physical and chemical adsorbent has been discussed and compared on the basis of COP (Coefficient of Performance) and SCP (Specific cooling Power). A detailed comparative analysis has been provided between different composite adsorbents developed by using Silica-gel, Activated Carbon, Expanded Natural Graphite and Zeolite as a parent material. The performance of different composite adsorbents has been compared on the basis of thermal conductivity and adsorption capacity (of water, methanol, ethanol and CO2). Also, a novel composite adsorbent using polymeric binder (silica-gel and expanded natural graphite bound with polyvinyl alcohol) has been proposed and their physical properties are also discussed. In addition to this, three different methods of composite adsorbent materials preparation using silica-gel, activated carbon, zeolite with expanded natural graphite have been discussed. It is observed from the present study that the composite adsorbent of Metal Organic Frameworks shows better heat and mass transfer properties as compared to the conventional adsorbent. It is also observed that the performance of the adsorption refrigeration system can be improved significantly by developing high-performance composite adsorbents.

Analysis of Mechanical Properties of Unidirectional Flax Roving and Sateen Weave Woven Fabric-Reinforced Composites

Abstract Natural fiber-reinforced composites are getting more attention from researchers and manufacturing companies to replace metals and synthetic materials that have dominated the manufacturing industries. In this study, the mechanical properties of unidirectional (UD) flax roving-reinforced composites and woven fabric-reinforced composites were investigated. Three different composites were prepared from flax rovings, which have the same linear density and epoxy resin matrix, with different reinforcement and composite preparation methods. The samples were subjected to experimental tests of flexural rigidity and tensile strength in a parallel and perpendicular direction to fiber orientation. The test results showed that flexural rigidity and tensile strength of flax fiber-reinforced composites are highly dependent on the direction of fiber orientation. The results also reveal that in a parallel direction to fiber orientation, UD composites have higher flexural rigidity and tensile strength than woven fabric-reinforced composite.

Nano- and macro-structured cerium oxide – Carbon nanotubes composites for the catalytic ozonation of organic pollutants in water

A novel methodology for the preparation of nanostructured layers of mechanically processed carbon nanotubes (CNT) on macro-structured supports was investigated as a means to prepare macro-structured composite catalysts consisting of a variety of different ceria – CNT combinations as ozonation catalysts. Two different synthesis routes were used for the preparation of the ceria: precipitation and sol-gel. The composite materials were prepared using different approaches: introduction of ball-milled CNT during the synthesis procedure; ball-milling the pure ceria together with as-received CNT; and decoration of ball-milled CNT with well-dispersed ceria through incipient wetness impregnation. The powder composite catalysts were then transferred onto macro-structured supports by using the aforementioned novel methodology for the preparation of slurries suitable to be used in the dip-coating of the macro-structures. A further structured composite catalyst was also prepared using a two-step approach by dipping a previously prepared CNT structured catalyst in a ceria solution. The powder and structured composite catalysts were then tested as ozonation catalysts in semi-batch and continuous experiments. It was found that the different ceria synthesis routes and the composite preparation methods affected both the catalytic performance of the powder composites and also the characteristics of the slurry used for dip-coating of the macro-structured supports. The ball-milling of sol-gel ceria together with CNT resulted in the most active powder catalyst, but the impregnated CNT with well-dispersed ceria was found to be the most active structured catalyst prepared from coating with the powder composites. The two-step structured catalyst prepared by dipping in a ceria-sol was able to achieve the highest removal of oxalic acid (85 % at steady-state continuous operation); however, due to the more energy intensive preparation procedure, its use in practical applications might not be the most recommendable.