Composites Research Articles

Construction of porous graphene and network carbon nanotubes to develop high-performance and multifunctional carbon fiber composites

Structurally and functionally integrated carbon fiber reinforced polymer composites (CP) are indispensable in electronic devices, where the combination of brilliant mechanical properties, electromagnetic shielding properties and thermal management capabilities are required. Designing and optimizing the interface structure is an effective solution to the above problems. In this work, porous graphene and network carbon nanotubes were successfully integrated into CP. Graphene and carbon nanotubes form a crosslinked structure in which graphene improve the fiber/matrix interfacial bonding and carbon nanotubes enhance the matrix cohesion. Due to their synergistic enhancement, the tensile strength (183.00 ± 5.66 MPa) of graphene and carbon nanotubes reinforced CP (CG-CP) is increased by 65.85 % and the wear rate (1.19 × 10–13 ± 0.05 × 10−13 m3(N·m)−1) is reduced by 74.52 %. Further, the crosslinked structure of graphene and carbon nanotubes creates a high-conductivity and heat-conductive transmission channel, enabling CG-CP to achieve an electromagnetic interference shielding efficiency of up to 48.94 dB in the X-band and 52.62 dB in the Ku-band at a thickness of 0.3 mm, and a 20.98 % improvement of thermal conductivity (0.767 ± 0.002 W(m·K)−1), which simultaneously achieves excellent electromagnetic shielding performance and thermal management capability. The high-performance and multifunctional CG-CP offers a broad prospect regarding the application of advanced electronic devices.

The effect of dental material type and masticatory forces on periodontitis-derived subgingival microbiomes

Restorative dental materials can frequently extend below the gingival margin, serving as a potential haven for microbial colonization, and altering the local oral microbiome to ignite infection. However, the contribution of dental materials on driving changes of the composition of the subgingival microbiome is under-investigated. This study evaluated the microbiome-modulating properties of three biomaterials, namely resin dental composites (COM), antimicrobial piezoelectric composites (BTO), and hydroxyapatite (HA), using an optimized in vitro subgingival microbiome model derived from patients with periodontal disease. Dental materials were subjected to static or cyclic loading (mastication forces) during biofilm growth. Microbiome composition was assessed by 16S rRNA gene sequencing. Dysbiosis was measured in terms of subgingival microbial dysbiosis index (SMDI). Biomaterials subjected to cyclic masticatory loads were associated with enhanced biofilm viability except on the antibacterial composite. Biomaterials held static were associated with increased biofilm biomass, especially on HA surfaces. Overall, the microbiome richness (Chao index) was similar for all the biomaterials and loading conditions. However, the microbiome diversity (Shannon index) for the HA beams was significantly different than both composites. In addition, beta diversity analysis revealed significant differences between composites and HA biomaterials, and between both loading conditions (static and cyclic). Under static conditions, microbiomes formed over HA surfaces resulted in increased dysbiosis compared to composites through the enrichment of periopathogens, including Porphyromonas gingivalis, Porphyromonas endodontalis, and Fretibacterium spp., and depletion of commensals such as Granulicatella and Streptococcus spp. Interestingly, cyclic loading reversed the dysbiosis of microbiomes formed over HA (depletion of periopathogenes) but increased the dysbiosis of microbiomes formed over composites (enrichment of Porphyromonas gingivalis and Fusobacterim nucleatum). Comparison of species formed on both composites (control and antibacterial) showed some differences. Commercial composites enriched Selenomonas spp. and depleted Campylobacter concisus. Piezoelectric composites effectively controlled the microbiome viability without significantly impacting the species abundance. Findings of this work open new understandings of the effects of different biomaterials on the modulation of oral biofilms and the relationship with oral subgingival infections.

Exploring the possibility of undesirable manufacturing heritage reduction in parts made of composites and their joints

The object of the research is the possibility of improving the quality of parts made of composites (CM) by means of pre-polymerization treatment of the wet package with intensive pulse loading. The existing technologies for forming parts from CM involve the compaction of the collected impregnated package of reinforcement layers and their subsequent polymerization under the influence of pressure and temperature. As a result of this technology, residual thermal and shrinkage stresses occur in the composite package, which lead to undesirable spatial deformations of profile parts, a violation of monolithicity in the areas of the connection of the composite and metal ends. Using the example of an angular composite profile with a profile with doubler on one of the caps, the residual stress calculation is given and the method of choosing rational angles for stacking the reinforcing material is demonstrated in order to reduce the amount of residual thermal stresses that arise in the composite during its polymerization. The dependence of the twisting parameter of a long-dimensional composite profile of constant cross-section along its axis on the modulus of elasticity and the coefficient of linear temperature expansion is plotted. The work explains the mechanism of the emergence of such harmful technological heredity. The value of the residual deformations was estimated. Based on the analysis of the impregnation process of dry reinforcing material with a binder, the task of increasing the maximum contact area of the binder with fibers is formulated and a possible method of its increase is analyzed. Thus, using the model of capillaries between the fibers of the composite, it is concluded that it is necessary to apply additional pressure to the binder for its deeper advancement between the fibers. Using a synergistic method of combining knowledge from various branches of industry and based on experimental data, a process of pre-polymerization loading of the impregnated package with intense impulse loading (shock waves) is proposed. This process greatly improves the quality of parts of the units produced.

Optimization of the Alkali-Silane Treatment of Agave lechuguilla Fibers (Ixtle) for Potential Reinforcement in Polymeric Composites

Reinforced polymeric composites with natural fibers have garnered significant interest in recent years due to the need for biomass utilization and the requirements of various industries, such as automotive and construction. Among these natural fibers, Agave lechuguilla fiber, commonly known as ixtle (FIx) or Tampico fiber, exhibits important characteristics such as length, high strength, and durability. However, there is limited literature on its conditioning, functionalization, and utilization as a reinforcing material in polymeric composites (CP). This study presents the optimization of the alkali-silane treatment of FIx, identifying the most suitable reaction conditions to enhance their thermal stability, tensile strength, and silane coupling agent (ACSi) grafting on the fiber surface. The chemical treatment with ACSi proved highly effective, resulting in a significant grafting content, which was confirmed through FTIR and SEM–EDS analyses. The high level of functionalization did not compromise the mechanical performance of the fibers, suggesting that functionalized FIx holds great potential as a reinforcing material in CP. These findings open new paths for the sustainable use of Agave lechuguilla fibers, contributing to the development of environmentally friendly and high-performance polymeric composites in various industrial applications.

Synthesis, Characterization and Antibacterial Activity of PolypyrroleMontmorillonite Nanocomposites

Conducting polymers and its composites found to be promising candidate for the medical and electroanalytical application in various fields. Significant functional exercise on Montmorillonite clay proves wide appliction in food additive , for antibacterial activity against tooth and gum decay, as sorbent for nonionic, anionic, and cationic dyes, and the use as catalyst in organic synthesis. Polypyrrole and Montmorillonite clay are used in the synthesis of Polypyrrole/ Montmorillonite nanocomposites by chemical oxidative method. Obtained PPy/montmorillonite composites are characterised by UV, FTIR and morphology and composition analysis are also done by using FESEM and EDX. Biological activities of the Polypyrrole/Montmorillonite conducting polymers composites (CPs) are studied by using the Bacillus, E.Coli, Pseudomonae as a bacterial cultures. PPY/7.5% MMT composite show antibacterial activity for the Bacillus,bacteria but for the E.Coli, Pseudomonaeno no activity.

Interface modification of carbon fiber composites by interlocked brushite nanopins and brushite nanosheets

The interface region of carbon fiber/epoxy composites (CE) plays an essential role in mechanical and biotribological properties for bone replacement application. However, the debonding interface of fiber/matrix in CE presents a significant obstacle to their practical deployment. In this study, two component brushites with interlocked structure reinforcement have been designed and synthesized into CE for synchronously upgrading the tensile strength and biotribological property. Especially, brushite nanopins (BSp) are radially grafted on the surface of carbon fibers in order to optimize the interface between carbon fiber and epoxy matrix via forming intertwined filamentous architectures. In addition, brushite nanosheets (BSs) are vertical growth on the surface of BSp in order to promote the penetration of the epoxy and improve the cohesion of epoxy matrix. Thus, the mechanical and biotribological properties of BSp and BSs (BSps) modified CE (BSps-CE) have been markedly enhanced. In contrast with CE, the tensile strength of BSps-CE (97.22 MPa) is increased by 27%, and the elastic modulus is increased by 54%. The wear rate of BSps-CE (0.283×10−15 m3(N·m)−1) is greatly reduced by 169% compared with CE (0.763×10−15 m3(N·m)−1). The boost of mechanical strength and the reduce of wear rate means that the service life of the BSps-CE as an artificial implant in human body is prolonged, and the wear debris is reduced. This work demonstrates that it is feasible for BSps to improve the mechanical and biotribological properties of CE by interfacial modification. Superior mechanical and biotribological performances of BSps-CE show its potential for orthopedic implant and fracture internal fixing applications.

Synthesis of superabsorbent composite based on chitosan-g-poly(acrylamide)/attapulgite

The production of environmentally friendly SAP using biodegradable natural resources such as chitosan was synthesized for water saving and controlled-released fertilizer. Chitosan-g-poly(acrylamide)/attapulgite superabsorbent composites (CTS) were created by crosslinking N,N'-methylene-bis-acrylamide (MBA) with chitosan (Ch), acrylamide, and attapulgite (ATP) and initiating the reaction with potassium persulfate (KPS). Spectroscopic techniques such as Fourier transform infrared spectroscopy, thermal gravimetric analysis (TGA), and scanning electron microscope were used to characterize the composite structures. It was done to determine how certain characteristics, such as the initiator percentage, crosslinker ratio, and clay content, affected the composite's ability to swell. The results confirmed that the thermal stability of the composite was improved by the addition of ATP. The maximum swelling was attained when the KPS concentration was 0.1 g. However, the addition of 0.2 g of KPS created a composite with a lower swelling capacity. When the amount of ATP was increased by up to 0.4 g, the swelling increased from 210 to 319 g/g. However, as the clay amount was increased further to 1.2 g, the swelling capacity decreased to 170 g/g. As pH increased to 3.0, the swelling of ATP2 grew larger; nevertheless, it shrank between pH values of 3 and 6. As the pH climbed to 8, the swelling sharply grew. The chosen composition was evaluated as a controlled-release method for urea fertilizer and swelled to 319 g/g in water (CTS2). The findings demonstrated that when the formulation's ATP content was increased from 0 to 1.2 g, the release rate was delayed, and the release length increased from 5 to 21 h.Graphical abstract

Constructing network-shaped hydroxyapatite interlayer for carbon fiber composites

Hydroxyapatite interlayer was designed and fabricated in carbon fiber reinforced epoxy composites (COE), forming carbon fiber-hydroxyapatite-epoxy ternary composites (CHE). The microstructure, mechanical and biotribological properties of CHE were investigated. The hydroxyapatite interlayer grew uniformly on the surface of carbon fibers, exhibiting network morphology with numerous micrometer-scale pores. The tensile strength and the elastic modulus of CHE were increased by 17.8% and 90.1%, respectively compared with that of COE. The friction coefficient of CHE was increased by 23.5% and the wear rate of CHE was reduced by 28.3%. These results demonstrated the potential application CHE in human bone replacement.

Electrical and shielding properties of epoxy composites with Ni–C and Co–C core-shell nanoparticles

The electrical and microwave shielding properties of epoxy-based composites (CMs) filled with metal-nanocarbon Ni–C and Co–C core-shell particles have been studied for the broad frequency range (16–67) GHz. The decrease of electrical resistivity of CMs with the increase of Ni content in core-shell particles and temperature in the range of 77–293 K was found. The observed sufficient increase of microwave shielding efficiency (32–40 dB at sample thickness of 2.2 mm) in K a - and V-band for CMs with high Ni content correlates with increased electrical conductivity . A high microwave absorption index (0.999 at f = 65 GHz) of (Me–C)/epoxy CMs can be attributed to the enhanced dielectric and magnetic losses. The modeling of microwave absorption capability of 60 wt% (Ni x -C)/epoxy CMs showed that the microwave absorption peaks can be observed only for the narrow frequency range, (18–25) GHz at a sample thickness of 0.6–1.0 mm with the effective bandwidth (2.3–4.8) GHz. • Epoxy composites filled with 60 wt% of (Ni–C) and (Co–C) core-shell particles. • Decrease of electrical resistivity with increase of Ni content and temperature. • Increase of EMI shielding due to enhanced electric loss for higher Ni content. • Reflection loss in (Ni–C)/epoxy composites versus Ni content and sample thickness. • High microwave absorption index (∼0.999 at f = 65 GHz) for (Ni–C)/epoxy composites.

Impact of the Nanocarbon on Magnetic and Electrodynamic Properties of the Ferrite/Polymer Composites.

Binary and ternary composites (CM) based on M-type hexaferrite (HF), polymer matrix (PVDF) and carbon nanomaterials (quasi-one-dimensional carbon nanotubes—CNT and quasi-two-dimensional carbon nanoflakes—CNF) were prepared and investigated for establishing the impact of the different nanosized carbon on magnetic and electrodynamic properties. The ratio between HF and PVDF in HF + PVDF composite was fixed (85 wt% HF and 15 wt% PVDF). The concentration of CNT and CNF in CM was fixed (5 wt% from total HF + PVDF weight). The phase composition and microstructural features were investigated using XRD and SEM, respectively. It was observed that CM contains single-phase HF, γ- and β-PVDF and carbon nanomaterials. Thus, we produced composites that consist of mixed different phases (organic insulator matrix—PDVF; functional magnetic fillers—HF and highly electroconductive additives—CNT/CNF) in the required ratio. VSM data demonstrate that the main contribution in main magnetic characteristics belongs to magnetic fillers (HF). The principal difference in magnetic and electrodynamic properties was shown for CNT- and CNF-based composites. That confirms that the shape of nanosized carbon nanomaterials impact on physical properties of the ternary composited-based magnetic fillers in polymer dielectric matrix.

Investigation of sintering properties and ceramifying process of amorphous silica/mica‐based ceramifiable polyethylene composites

SummaryCeramifiable polyolefin‐based composites are promising materials for fire‐resistant cables. Many studies have been focused on improving the ceramifiable properties by developing various composite matrixes with optimum inorganic fillers. Few studies have been carried out to compare the sintering properties of ceramifying powder (CP) and ceramifiable polymer‐based composites directly. In this work, a low‐temperature sintering CP, formulated with mica, amorphous silica and glass frits, and filled into polyethylene (PE) matrix to prepare a ceramifiable PE composites (CPE). The sintering properties, including the flexural strength, apparent porosity and volume variation, were tested at calcination temperatures from 600 to 900°C. Results showed that the CP had better sintering properties than the CPE at the same calcined temperatures, but the gap between the two continued to decrease as the temperature increased. The negative effect of PE matrix decomposition on the ceramifying process was more pronounced in the low‐temperature ranges (600 and 700°C). As the temperature reached above 700°C, the sintering of the CP was accelerated, and the sintering properties of composite residue increased significantly. The ceramifying process of the CPE was investigated by thermalgravimetric analysis, X‐ray diffraction and scanning electron microscopy. The analyses demonstrated that the induction of the CP improved the thermal stability of the CPE, and played the main role in the structure evolution of the composite residue. During the ceramifying process, the glass frits melted at low temperatures, bridging mica and amorphous silica. As the temperature increased to 800 and 900°C, mica had a eutectic reaction with the glass liquid phase, facilitating the change of a bridging structure to the continuous island structure responsible for the superior mechanical and fire‐resistant properties of the CPE.

Experimental study of mechanical properties of sisal/jute fibers hybrid sandwich composite

The objective of this research is to examine the mechanical characteristics of a composite material made from Jute fiber (JF) and sisal fiber (SF) for use in orthopedic long bone plates. JF/epoxy forms the exterior layers of the JF/SF hybrid composite, whereas SF/epoxy forms the inside layers. Similarities between the composite plate and the skeleton have been noted (spongy interior cancellous matrix and rigid exterior cortical). Samples of the manufactured hybridized sandwich composites were subjected to experimentation for finding tensile, micro hardness, compressive and flexural testing to determine their mechanical properties. The experimentation is made on the standard test specimen. In addition, the contact angle (CA) and water absorption of the Sisal Fiber/epoxy and Jute Fiber/Sisal Fiber/epoxy composites is determined to get a better idea of their wettability. In addition, the ethanol infiltration technique was used to calculate the porosity of the JF/SF compo sites scaffold specimen. The mechanical tests reveal that the JF/SF hybridized composites have a bending strength of 345 MPa, UTS of 148 MPa, and a compressive strength of 382 MPa; moreover, the bending tests reveal a Young's modulus of (21.56 GPa), which is higher than the tensile modulus (6577 MPa) and compressive modulus (2047 MPa). Research into the scaffolds' wettability revealed that the JF/SF composites were hydrophobic (CA = 92.41), absorbing 3.436% less water than the SF/composites (6.953%). Hydrophilicity (CA = 54.28 ± 1.71) is evident in SF composites. The results of the experiments show that the JF/SF hybrid composite has potential as a bone fracture plate material in orthopedics.

Mechanical properties of HNT filled carbon fabric epoxy composites

Recent researches are witnessing that nano fillers are significantly contributing the enhancement of strength of solid materials. In the current investigation carbon fabric reinforced epoxy matrix added with halloysite nanotubes (HNT) composites were fabricated using hand layup technique followed by hot pressing. The carbon fabric reinforced epoxy matrix composites (C-E) were fabricated with the addition of 0.1, 0.2, 0.5 and 0.75 wt% halloysite nanotubes (HNT) and tested for its mechanical properties: tensile strength and modulus, flexural strength and modulus using ASTM testing standards. The results revealed that tensile strength and modulus were increased up to 82% and 26.8% respectively and flexural strength and modulus were increased up to 29% and 28.5% respectively as compared to the unfilled carbon fabric-epoxy composites. Failure mechanisms were analysed using SEM photographs.

Electrical and thermal properties of epoxy composites filled with carbon nanotubes and inorganic particles

The electrical and thermal conductivity of the ternary epoxy composites (CMs) with two-component fillers, multiwall carbon nanotubes (MWCNT)/TiO2, and MWCNT/carbonyl iron (Fe) have been investigated. The increase of the percolation threshold was found for the ternary CMs compared to MWCNT/epoxy CMs. At MWCNT content higher than 3 wt.%, the conductivity of the ternary CMs is much higher than in MWCNT/epoxy. The temperature dependencies of the electrical resistivity were analyzed within the fluctuation-induced tunneling conductivity model. It was found that adding of two-component fillers MWCNT/TiO2 or MWCNT/Fe into epoxy promotes smaller changes in thermal conductivity compared to the two-phase MWCNT/epoxy composites.

Sulfide synergistic electrochemical activity for high-performance alkaline rechargeable microbatteries

Alkaline rechargeable microbatteries have attracted considerable and sustained attention in recent years. However, the complicated fabrication process and the limited specific capacitance of electrodes are still key problems for the development of microbatteries. Herein, we develop a simple approach to enhance electrochemical activity of electrodes via rational design of material components. A sulfide synergistic bimetallic electrode composed of Ni-Co layered double hydroxides (NiCo-LDHs) and Co4S3 composites (NiCo-LDHs-S) is prepared by one-step electrodeposition. Thanks to the richer redox couples in NiCo-LDHs-S and high conductivity of Co4S3, the areal capacitance of NiCo-LDHs-S cathode is ~ 5.8 times, ~ 19.7 times and 1.5 times as high as that of electrodes based on cobalt sulfur composites (Co-O-S), nickel sulfur composites (Ni-O-S) and NiCo-LDHs, respectively. A carbon-modified Fe3O4 (Fe3O4@C) anode is prepared to promote electron transfer, leading to an areal capacitance of 207.2 mC cm−2 at a current density of 2 mA cm−2. An efficient alkaline rechargeable microbattery using NiCo-LDHs-S as a cathode and Fe3O4@C as an anode is obtained and shows an areal capacitance of 61.7 mC cm−2 and an energy density of 16.4 μWh cm−2 (1.0 mW cm−2).

A novel combination of precursor pyrolysis assisted sintering and rapid sintering for construction of multi-composition coatings to improve ablation resistance of SiOC ceramic modified carbon fiber needled felt preform composites

A double-layer coating composed of MoSi2–SiO2–SiC/ZrB2–MoSi2–SiC was designed and successfully constructed by a novel combination of precursor pyrolysis assisted sintering and rapid sintering to improve the ablation resistance of SiOC ceramic modified carbon fiber needled felt preform composites (CSs). The ZrB2–MoSi2–SiC inner layer coating was in relatively uniform distribution in the zone of 0–3 mm from the surface of CSs through the slurry/precursor infiltration in vacuum and SiOC precursor pyrolysis assisted sintering, which played a predominant role in improving oxidation and ablation resistance and maintaining the morphology of CSs. The MoSi2–SiO2–SiC outer layer coating was prepared by the spray and rapid sintering to further protect CSs from high-temperature oxidation. The ablation resistance of CSs coated with double-layer coating was evaluated by an oxygen-acetylene ablation test under the temperature of 1600–1800 °C with different ablation time of 1000 and 1500 s. The results revealed that the mass recession rates increased with the rise of ablation temperature and extension of ablation time, ranging from 0.47 g/(m2·s) to 0.98 g/(m2·s) at 1600–1800 °C for 1000 s and from 0.72 g/(m2·s) to 0.86 g/(m2·s) for 1000–1500 s at 1700 °C, while the linear recession rates showed negative values at 1700 °C due to the formation of oxides, such as SiO2 and ZrO2. The ablation mechanism of the double-layer coating was analyzed and found that a SiO2–ZrO2–Mo4.8Si3C0.6 oxidation protection barrier would be formed during the ablation process to prevent the oxygen diffusion into the interior CSs, and this study provided a novel and effective way to fabricate high-temperature oxidation protective and ablation resistant coating.

A Critical Synthesis Over Natural Fibers, Include Bamboo and Hemp Flavoured with Glass Fiber Reinforced Plastic

Researchers and academicians are preferably focusing on natural fibers to fabricate in polymer composites for their environmentally friendly and sustainability specialty. The exclusive objective of this review article is to exhibit an inclusive idea of the principal apposite as well as widely used natural fiber reinforced polymer comp osites (NFPCs) and their purposes. Based on the strand class, basis and construction the possessions of NFPCs differ. This work critically synthesizes the exceptional inherent feature of usualstrandstaken in a polymeric matrix as an additive,promotingfabrication of inexpensive and insubstantial composites for weighthandling structures.

Polyacrylamide-polyaniline composites: the effect of crosslinking on thermal, swelling, porosity, crystallinity, and conductivity properties

When the synthesis of hydrogels, which are a hydrophilic group of polymers, occurs below the freezing point of water, the hydrogels gain a perfect property: porosity. Hydrogels with this property and resulting sponge-like structure are called cryogels (CRYs). The porosity of cryogels is affected by the amount of crosslinker used. In this study, how the amount of crosslinker affected the porosity initially was investigated, along with thermal, swelling, and crystallinity properties of polyacrylamide (PAAM) cryogels. Additionally, a series of composites (COMs) were synthesized with polyaniline (PAN) in the pore spaces of CRYs and again the effect of varying pore size on the electrical conductivity of COMs was researched. In the cryogel series, as the amount of N,N′-methylenbisacrylamide (MBA) increased, the pore size increased. The S, P, Ps, and Vp parameters increased in general with the MBA increase. The conductivity values of composites were determined in the interval of 1.6 × 10−3-4.5 × 10−3 S cm−1.

Inorganic carbonate composites as potential high temperature CO2 sorbents with enhanced cycle stability.

A calcium magnesium carbonate composite (CMC) material containing highly porous amorphous calcium carbonate (HPACC) and mesoporous magnesium carbonate (MMC) was synthesized. CMCs with varying HPACC : MMC mol ratios and high BET surface area (over 490 m2 g−1) were produced. The CMCs retained the morphology shared by HPACC and MMC. All these materials were built up of aggregated nanometer-sized particles. We tested the CO2 uptake properties of the synthesized materials. The CMCs were calcined at 850 °C to obtain the corresponding calcium magnesium oxide composites (CMOs) that contained CaO : MgO at different mol ratios. CMO with CaO : MgO = 3 : 1 (CMO-3) showed comparable CO2 uptake at 650 °C (0.586 g g−1) to CaO sorbents obtained from pure HPACC (0.658 g g−1) and the commercial CaCO3 (0.562 g g−1). Over 23 adsorption–desorption cycles CMOs also showed a lower CO2 uptake capacity loss (35.7%) than CaO from HPACC (51.3%) and commercial CaCO3 (79.7%). Al was introduced to CMO by the addition of Al(NO3)3 in the synthesis of CMC-3 to give ACMO after calcination. The presence of ∼19 mol% of Al(NO3)3 in ACMO-4 significantly enhanced its stability over 23 cycles (capacity loss of 5.2%) when compared with CMO-3 (calcined CMC-3) without adversely affecting the CO2 uptake. After 100 cycles, ACMO-4 still had a CO2 uptake of 0.219 g g−1. Scanning electron microscope images clearly showed that the presence of Mg and Al in CMO hindered the sintering of CaCO3 at high temperatures and therefore, enhanced the cycle stability of the CMO sorbents. We tested the CO2 uptake properties of CMO and ACMO only under ideal laboratory testing environment, but our results indicated that these materials can be further optimized as good CO2 sorbents for various applications.

On the Interactions and Synergism between Phases of Carbon⁻Phosphorus⁻Titanium Composites Synthetized from Cellulose for the Removal of the Orange-G Dye.

Carbon–phosphorus–titanium composites (CPT) were synthesized by Ti-impregnation and carbonization of cellulose. Microcrystalline cellulose used as carbon precursor was initially dissolved by phosphoric acid (H3PO4) to favor the Ti-dispersion and the simultaneous functionalization of the cellulose chains with phosphorus-containing groups, namely phosphates and polyphosphates. These groups interacted with the Ti-precursor during impregnation and determined the interface transformations during carbonization as a function of the Ti-content and carbonization temperature. Amorphous composites with high surface area and mesoporosity were obtained at low Ti-content (Ti:cellulose ratio = 1) and carbonization temperature (500 °C), while in composites with Ti:cellulose ratio = 12 and 800 °C, Ti-particles reacted with the cellulose groups leading to different Ti-crystalline polyphosphates and a marked loss of the porosity. The efficiency of composites in the removal of the Orange G dye in solution by adsorption and photocatalysis was discussed based on their physicochemical properties. These materials were more active than the benchmark TiO2 material (Degussa P25), showing a clear synergism between phases.