Supercritical Carbon Dioxide Conditions Research Articles

Fast Synthesis of Olefin-Linked Covalent Organic Frameworks via Supercritically Solvothermal Polymerization.

Covalent organic frameworks (COFs) are newly emerging yet rapidly developed porous crystalline polymeric materials, which feature topological designability, structural diversity, and porosity tunability. However, most of the reported COFs hitherto are prepared by a solvothermal method, which needs a long reaction time, especially for the olefin-linked COFs, which hinders their practical applications. Herein, we report the fast growth of olefin-linked COFs synthesized by the supercritical solvothermal method under supercritical carbon dioxide conditions. Via optimization of the reaction conditions, olefin-linked COFs are prepared within 6 h, which is period much shorter than that of the traditional solvothermal method. The as-obtained COFs feature two distinct morphologies, namely, spherical and rod-like. Interestingly, the rod-like crystal shows polarized light extinction and rebrightening phenomena, indicating the high crystallinity. After being doped with I2, the obtained I2@COFTMT-PA shows a Hall mobility of 1.94 cm2 V-1 S-1, indicating its potential applications in optoelectronics. This work expands the application of the supercritically solvothermal method to the fast growth of olefin-linked COFs and solves a long-standing challenge in chemical science, which opens up opportunities for basic research as well as practical applications of olefin-linked COFs and other polymeric materials.

Upgrading vacuum residue in a supercritical CO2 environment with polypropylene and steam: Insights into products distribution and characterization of liquid products

The pyrolysis of vacuum residue (VR) using polypropylene (PP) under supercritical carbon dioxide (scCO2) conditions represents a novel approach to converting this abundant and difficult-to-process feedstock into lighter liquid products. In this paper, a set of experiments was performed to analyze the impact of scCO2, PP and steam on the yields of pyrolysis products (i.e., liquid, gas and coke) and characteristics of the liquid fractions. The findings indicated notable improvements when scCO2 was used instead of subcritical CO2 in the pyrolysis of VR with PP. These included decreased viscosity and improved API gravity, alongside increased maltene yield and reduced coke yield. Furthermore, the inclusion of PP markedly elevated the quality of the obtained liquid, whereas steam + scCO2 primarily affected the product distribution by raising the yield of coke and gas fractions. VR pyrolysis under scCO2 conditions at 380 °C, 8 MPa, PP/VR ratio of 0.23 for 60 min in a batch system, without the use of catalyst, resulted in the highest liquid yield of 83.7 ± 1.9 wt%, and minimum coke yield of 9.8 ± 1.3 wt%. Under these conditions, the upgraded liquid consisted of 75.2 wt% light and middle distillates with boiling points below 350 °C. Additionally, the proportion of oxygenates in the pyrolysis oil reduced by 60.5 %, improving its heating value. Moreover, adding PP to the upgrading process resulted in a higher proportion of isoparaffins, cycloparaffins, and aromatics, coupled with a decrease in olefins, aligning the liquid specifications more closely with fuel standards.

Research on the Biogas Production Mechanism of Mudstone in the Qaidam Basin under Different CO2 Pressures.

Mudstone, a class of sedimentary rocks rich in organic matter, possesses considerable potential for biogas production. Mudstones possess a rich biological origin, which is conducive to refining the mechanisms and enrichment patterns of biogenic gas reservoirs. This has significant theoretical and practical implications for guiding the exploration and development of Quaternary mudstone gas reservoirs. Furthermore, the Qaidam Basin is an excellent place for the geological storage of CO2 due to its rich petroleum reservoir conditions. Experimental research on biogas production under diverse CO2 pressure-mudstone-microorganism-water interactions is conducted to determine the biogas production mechanism of mudstone under different CO2 pressures during sequestration circumstances. According to the results: (1) under supercritical carbon dioxide conditions, there is a slight initial increase in biogas production, followed by a gradual decrease. The periods and peaks of gas production vary among the different reaction groups. As carbon dioxide pressure increases, the gas production cycle lengthens significantly, while the gas yield declines. (2) Siderite and secondary carbonate minerals have increased in the mudstone's mineral fraction both before and after biogas production, while clay mineral groups have decreased. Specifically, there was a notable drop in chlorite and kaolinite. (3) Microorganism species in the system were analyzed, and the results showed that there was a gap in each microorganism's ability to adapt to its surroundings, and the diversity and quantity of bacteria declined with increasing pressure. After carbon dioxide was fluxed, there was a considerable shift in the pattern of biogas generation, which consequently had a major impact on the alterations in mineral fractions.

Enhancing Carbon Nanotube Yarns via Infiltration Filling with Polyacrylonitrile in Supercritical Carbon Dioxide.

Carbon nanotube (CNT) fibers are renowned for their exceptional axial tensile strength and modulus. However, in yarn form, they frequently encounter transverse loading in practical applications, which exposes their suboptimal mechanical attributes rooted in inadequate inter-tube interactions and yarn surface defects. Efforts to mitigate micro-slippage among CNTs have encompassed gap-filling methodologies with varied materials, yet the outcomes have fallen short of expectations. This work aimed to enhance the mechanical properties of CNT yarns via infiltration with polyacrylonitrile (PAN) under supercritical carbon dioxide (sc-CO2) conditions. PAN was strategically chosen for its capability to undergo pre-oxidation and subsequent carbonization, leading to robust graphitic reinforcement. Leveraging sc-CO2's swelling and high permeability properties, the infiltration process effectively plugged interstitial spaces, elevating the yarn's tensile strength to 277.50 MPa and Young's modulus to 5094.05 MPa. Additional enhancements were realized after pre-oxidation, conferring a dense, reinforced shell structure that augmented tensile strength by 96.93% and Young's modulus by 298.80%. Scanning electron microscopy (SEM) analyses revealed a homogeneous PAN distribution within the yarn matrix, corroborated by X-ray photoelectron spectroscopy (XPS) evidence of C-N bonding, indicative of a successfully interlaced network. Consequently, this investigation introduces a novel strategy to tackle micro-slippage in CNT yarns, thereby achieving substantial improvements in their mechanical resilience.

Impact of supercritical carbon dioxide on the frictional strength of and the transport through thin cracks in shale

Understanding the mechanical and transport behavior of thin (i.e. small aperture) cracks slipping under supercritical carbon dioxide (sc-CO2) conditions is essential to evaluate the integrity of sealing formations with buoyant sc-CO2 below and the success of waterless fracturing. The two major items of interest in this work are frictional strength and permeability change of the crack. We used a triaxial cell that permits in situ visualization to conduct and monitor slippage along the faces of narrow cracks subjected to triaxial stresses. Such cracks are analogs to small geological faults. We tested carbonate-rich, 1-inch diameter Wolfcamp shale samples that are saw cut 30° to vertical to create a thin crack. Friction coefficients ranged from about 0.6 to 0.8 consistent with expectations for brittle rocks. The sc-CO2 generally did not alter friction coefficient over the time scale of experiments. From a transport perspective, saturating cracks with sc-CO2 substantially decreased permeability of the crack by 26%–52%, while slip resulted in a variety of permeability responses. Overall, the combined impact of sc-CO2 saturation and slip reduced fault permeability for all tests. Our observations support the notion that the sealing capacity of some caprocks improves when saturated with sc-CO2 and that some slip of small fractures is not necessarily detrimental to caprock integrity.

Study on Surface Characteristics and Work Hardening of SiCp/Al Composites by SCCO2-MQL Combined with Ultrasonic Vibration Milling

This study investigated the milling of SiCp/Al composite materials using Polycrystalline Diamond (PCD) tools under various machining conditions, including dry cutting conditions, supercritical carbon dioxide (SCCO2) conditions, supercritical carbon dioxide cooling with minimum quantity lubrication (SCCO2-MQL) conditions, ultrasonic vibration conditions, and supercritical carbon dioxide cooling with minimum quantity lubrication combined with ultrasonic vibration conditions. The objective was to compare the surface roughness and morphology of the materials under different machining conditions. Furthermore, under dry cutting conditions and SCCO2-MQL combined with ultrasonic vibration, the effects of different milling parameters on the surface roughness and morphology of SiCp/Al composite materials were investigated through a univariate experiment. Microhardness tests were carried out on the machined workpieces to explore the influence of process conditions and milling parameters on work hardening. The experimental results indicate that among all the tested machining conditions, the SCCO2-MQL in combination with the ultrasonic vibration process significantly reduced the surface roughness of the material. When the milling speed was increased from 40 m/min to 120 m/min, both the surface roughness and the degree of work hardening first increased and then decreased. As the feed rate or cutting depth increased, the degree of work hardening also increased. Therefore, under SCCO2-MQL combined with ultrasonic vibration conditions, it is recommended to use a milling speed of more than 60 m/min and avoid using high feed rates and cutting depths in order to optimize the machining performance.

Corrosion Behavior of Alumina-Forming Austenitic Steel in Supercritical Carbon Dioxide Conditions: Effects of Nb Content and Temperature.

The corrosion behavior of alumina-forming austenitic (AFA) stainless steels with different Nb additions in a supercritical carbon dioxide environment at 500 °C, 600 °C, and 20 MPa was investigated. The steels with low Nb content were found to have a novel structure with a double oxide as an outer Cr2O3 oxide film and an inner Al2O3 oxide layer with discontinuous Fe-rich spinels on the outer surface and a transition layer consisting of Cr spinels and γ'-Ni3Al phases randomly distributed under the oxide layer. Oxidation resistance was improved by accelerating diffusion through refined grain boundaries after the addition of 0.6 wt.% Nb. However, the corrosion resistance decreased significantly at higher Nb content due to the formation of continuous thick outer Fe-rich nodules on the surface and an internal oxide zone, and Fe2(Mo, Nb) laves phases were also detected, which prevented the outward diffusion of Al ions and promoted the formation of cracks within the oxide layer, resulting in unfavorable effects on oxidation. After exposure at 500 °C, fewer spinels and thinner oxide scales were found. The specific mechanism was discussed.

Reinforcing a Thermoplastic Starch/Poly(butylene adipate-co-terephthalate) Composite Foam with Polyethylene Glycol under Supercritical Carbon Dioxide

Biodegradable foams are a potential substitute for most fossil-fuel-derived polymer foams currently used in the cushion furniture-making industry. Thermoplastic starch (TPS) and poly(butylene adipate-co-terephthalate) (PBAT) are biodegradable polymers, although their poor compatibility does not support the foam-forming process. In this study, we investigated the effect of polyethylene glycol (PEG) with or without silane A (SA) on the foam density, cell structure and tensile properties of TPS/PBAT blends. The challenges in foam forming were explored through various temperature and pressure values under supercritical carbon dioxide (CO2) conditions. The obtained experimental results indicate that PEG and SA act as a plasticizer and compatibilizer, respectively. The 50% (TPS with SA + PEG)/50% PBAT blends generally produce foams that have a lower foam density and better cell structure than those of 50% (TPS with PEG)/50% PBAT blends. The tensile property of each 50% (TPS with SA + PEG)/50% PBAT foam is generally better than that of each 50% (TPS with PEG)/50% PBAT foam.

Degradation of oil well cement with sodium chloride content exposed to supercritical carbon dioxide conditions: Temperature and pressure effects

Understanding the effects of temperature and pressure on the supercritical CO2 degradation of wellbore cement with NaCl content is essential for cementing oil wells in Brazil's deepwater pre-salt basin. The behavior of the cement paste used in cementing oil wells in this environment is very complex, with significant amounts of CO2 and a thick salt layer that requires a high demand on special wellbore cement capable of adequately sealing and assuring stability to the oil wells. For these reasons, the objective of this study was to investigate the effect of NaCl in cement on oil wells exposed to supercritical CO2 simulating pre-salt reservoir conditions. Cement slurry samples were prepared using Class G Portland cement (API 10 A), NaCl, water-to-cement (w/c) ratio of 0.46, and deionized water with (0 and 10% NaCl content). Supercritical CO2 experimental runs were carried out under different conditions for 7 h. Before and after exposure to CO2, the material was characterized by multiple analytical techniques. The results indicate that salt under temperature and pressure and the scCO2 environment accelerates the carbonation process by decomposing the hydrated product, increasing the CaCO3 content. In this scenario, investigations of the effect of adding NaCl to cement pastes are limited.

Synthesis of novel reactive disperse dyes comprising carbamate and cyanuric chloride groups for dyeing polyamide and cotton fabrics in supercritical carbon dioxide

Two types of novel reactive disperse dyes comprising carbamates (CNU-6A, CNU–6B and CNU–6C) and cyanuric chloride (CNU-8A, CNU–8B and CNU–8C) reactive functional groups were designed and synthesized from the anthraquinone parent body. The structures of these synthesized reactive disperse dyes have been defined by IR, 1H NMR, 13C NMR, HRMS and UV–Vis spectroscopy. Further, the dyeing experiments were performed on polyamide and cotton fabrics in supercritical carbon dioxide conditions with the 0.5% (owf) of dye concentration, at 25 MPa (pressure), and 120 °C (temperature) for 1 h. A significant improvement in the color strength and dye fixation efficiency has been observed for the carbamate reactive disperse dyes. This is due to the formation of a covalent bond between the carbamate functional group and the amine (–NH) and hydroxy (–OH) group of the fabrics. Besides, the dyed fabrics displayed favorable fastness (wash, crocking, light and sweat) properties indicating that the synthesized dyes meet the garment dyeing standards.

Effects of supercritical carbon dioxide under conditions potentially conducive to sterilization on physicochemical characteristics of a liposome formulation containing apigenin

In this work, the effects of four supercritical carbon dioxide (ScCO2) conditions potentially conductive to sterilization, on physicochemical characteristics of a liposome formulation containing apigenin (AG) were investigated. These conditions were: C1 (ScCO2/70 °C/150 bar/240 min), C2 (ScCO2/0.25% water/ 0.15% H2O2)/ 0.5% acetic anhydride/38 °C/85 bar/45 min), C3 (ScCO2/0.08% peracetic acid/35 °C/104 bar/180 min) and C4 (ScCO2/ 200 ppm H2O2/40 °C/270 bar/90 min). The results showed changes in color and a decrease in pH value of liposomes suspension after treatment with all tested conditions. Moreover, a decrease in liposome size with C1, C2 and C3 and an increase in the PDI with C1 and C3 were observed. For zeta potential, a decrease with C1, and an increase with C2 and C3 were found. Concerning the encapsulated AG, a moderate decrease, a strong decrease and a total disappearance were noted with conditions C1, C2 and C3 respectively.

Corrosion behavior of typical structural steels in 500 ℃, 600 ℃ and high pressure supercritical carbon dioxide conditions

Aiming at corrosion issues of structural materials in supercritical carbon dioxide Brayton systems, the corrosion behaviors of T91 and 316 were studied under S-CO2 at 500 ℃, 600℃and 20 MPa. The corrosion kinetics conform to the parabolic law. The corrosion products of T91 are mainly composed of outer columnar Fe3O4 and inner Fe-Cr spinel, which had porous structure and no protective effect for further corrosion. Thin and dense Cr2O3 formed on the 316 surface after 500℃corrosion.While large numbers of Fe-oxide nodules formed on surface of Cr-rich scale at 600 ℃. The corrosion mechanism was discussed.

Platinum Nanosheets Intercalated into Natural and Artificial Graphite Powders.

Insertion of sheet-type platinum particles (platinum nanosheets) between graphite layers was achieved by a thermal treatment of a mixture of platinum chloride (IV) and graphite powder (natural graphite or artificial graphite) under 0.3 MPa of chlorine at 723 K, followed by the treatment under 40 kPa of hydrogen pressure. Similar platinum nanosheets, which were 1-3 nm in thickness and 100-500 nm in width and had a number of hexagonal holes and edges with 120° angle, were formed between the layers of both natural graphite or artificial graphite; however, their location in the graphite layers depended on the type of graphite used. A number of platinum nanosheets were observed in the edge region of natural graphite particles which have flat surface. On the other hand, a number of platinum nanosheets were found inside and away from the edge of the artificial graphite particles especially in the vicinity of the cracks. Both the platinum nanosheet-containing artificial and natural graphite samples showed high selectivity to cinnamyl alcohol in cinnamaldehyde hydrogenation under supercritical carbon dioxide conditions, while spherical platinum particles, which were located on the surface of natural and artificial graphite, showed lower selectivity.

Nickel-Aluminum Oxide Aerogels: Super-adsorbents for Azo Dyes for Water Remediation.

Highly porous nickel–aluminum oxide aerogels were prepared according to a one-pot sol–gel process and dried under supercritical carbon dioxide conditions. Although the surface properties of these materials were very appealing for applications in catalysis, these aerogels were never applied in adsorption. The nickel effect on the structure and surface properties of the aerogels has been investigated via a broad range of structural, textural, and morphology characterization of the aerogels before and after heat treatment. The adsorption capacity of the as-synthesized and calcined aerogels for azo dyes was assessed under various experimental conditions. The presence of nickel in the aerogel boosts tremendously the surface reactivity and improves noticeably the adsorption capacity of the material. The adsorption capacities for the nickel–aluminum oxide aerogel with 40% nickel (qmax) are 900 mg g–1 for methyl orange, 1484 mg g–1 for orange II, and 1660 mg g–1 for Congo Red. The adsorption process is exothermic and follows pseudo-second-order kinetics.

Process Intensification for Enzyme Assisted Turmeric Starch Hydrolysis at Hydrotropic and Supercritical Condition

The turmeric rhizome (Curcuma longa) contains curcuminoids embedded in the starch matrix. It is important to target starch removal by hydrolysis to enhance the rate and extent of extraction of curcuminoids. Enzymes are green catalysts and their activity can be enhanced by working on certain parameters. In the case of starch hydrolysis, α- amylase is more efficient when the starch is in the gelatinized form than when it is in its natural form. α-Amylase activity improves under supercritical carbon dioxide (scCO2) conditions. Certain surfactants improve α- amylase activity. Hydrotropes are a mild form of the surfactants. However, there are no reports on hydrolysis of turmeric starch in hydrotropic or supercritical (SFC) conditions. The work in this report shows beneficial effect of hydrotrope on the enzymatic reactions. There is marked enhancement in the diffusion coefficient (De) for curcuminoid extraction. The increased starch hydrolysis also improves the solid filtration rates after hydrotropic extraction of the curcuminoids. In the case of hydrotropic extraction of curcuminoids alone otherwise the filtration rate decreases due to the sticky nature of the extraction mass, caused by swelling of the starch. The present work includes hydrolysis of turmeric starch in its natural and gelatinized forms using α-amylase in hydrotrope solution (HS) and scCO2.The starch hydrolysis parameters include α-amylase concentration, solid loading concentration, scCO2 flow rate, presence of modifier in scCO2, residence time and scCO2 backpressure. The optimum hydrolysis parameters are 200 IU.cm-3 of α-amylase, at 328 K, 10 % (w/w) of turmeric loading concentration, 6.5 reaction pH, 900 rpm agitation speed for hydrotropic hydrolysis while the optimum conditions are 5 % w/w turmeric loading concentration, 40 min of scCO2 residence time, 15 cm3 of scCO2 phase modifier and 15 MPa as the scCO2 backpressure. The De for hydrolysis in the HS for turmeric starch in gelatinized form (A) was 4.1 x 10-11 m2s-1 and De for starch hydrolysis methods including in HS for turmeric starch in natural state (B), SFC condition for turmeric starch in natural state (C) and SFC for turmeric starch in gelatinized (D) were approximately 4.1 x 10-12 m2s-1. De for native turmeric starch in the absence of hydrotrope and SFC (E), and in case of gelatinized turmeric starch hydrolysis in absence of SFC and hydrotrope were 4.1x 10-14 and 4.1x 10-13 m2s-1, respectively. The filtration rates for (A), (D), (B), (C), (E) were 2 x 10-4, 1.25 x 10-11, 1.4 x 10-11, 7.3 x 10-11, 8.2 x 10-11 kgm2s-1 respectively. The De and filtration rate were noted in order (A) > (D) > (B) > (C) > (E) > (F). The 2.5 h SFC and 2.15 h HS enzyme treated turmeric powder gave 6.56 and 2.44 x 106 times increased filtration rate for curcuminoid extraction compared to untreated turmeric powder.

Desorption of propylene glycol monomethyl ether acetate from activated carbon in supercritical CO2: Measurement and predictive modeling

The desorption behavior of propylene glycol monomethyl ether acetate (PGMEA), which is a volatile organic compound (VOC) used in semiconductor manufacturing, from activated carbon (AC) was experimentally and theoretically studied over a wide range of supercritical carbon dioxide (scCO2) conditions at T=(313 K to 353 K) and P=(10.0 MPa to 20.0 MPa) for the design of AC regeneration processes using scCO2. The experimental results reveal that the desorption ratio of PGMEA depended on the density of CO2, and is affected by its chemical structure and diffusivity of the VOC. A kinetic model based on the material balances of the VOC in the bulk phase and adsorption equilibria in the adsorbed phase described by the Dubinin–Astakhov equation was newly proposed to predict the desorption behavior. The model successfully predicted the desorption behavior using parameters determined from adsorption equilibrium and kinetic measurements of PGMEA on AC in scCO2.

Can supercritical carbon dioxide be suitable for the green pretreatment of plant fibres dedicated to composite applications?

This work explores the use of supercritical carbon dioxide (sc-CO2) conditions as an innovative and environmentally friendly treatment of plant fibres to optimize their performance for integration into composite materials. This study evaluates, in particular, the influence of this treatment on the mechanical, thermal, hygroscopic properties and biochemical features of industrial hemp bast fibres. Two distinct settings were tested by tuning time, temperature and pressure parameters to assess the influence of the severity of the treatment on the fibre quality. Results show that sc-CO2 treatment induces an increase in the fibre fineness and a decrease in their moisture sensitivity while maintaining their initial resistance to temperature. These changes are consistent with the measured decrease in the relative content of hemicelluloses. A significant decrease in the tensile rigidity and strength is also observed as a function of the severity of sc-CO2 treatment, counterbalancing a little bit the benefits retained on the other properties.

Hybrid CaO/Al2O3 aerogel as heterogeneous catalyst for biodiesel production

We report a new hybrid CaO/Al2O3 aerogel and its application as a heterogeneous catalyst for the production of biodiesel. These catalysts were successfully prepared for the first time via the rapid epoxide-initiated sol-gel process and dried under supercritical carbon dioxide conditions. The catalytic activity has been investigated under various conditions for the transesterification reaction of a waste cooking oil in the presence of methanol. The catalysts were characterized by FTIR spectroscopy, nitrogen adsorption-desorption technique, scanning electron microscopy, and powder X-Ray diffraction. The calcined aerogels at low CaO content were not as affected by calcination at 700 °C as their corresponding calcined alcogels and they revealed distinct structures, porosities, surface areas, and morphologies. The 3:1 CaO/Al2O3 calcined aerogel showed the best catalytic activity using the minimum amount of catalyst to produce high biodiesel yield and conversion with no soap formation. The effect on biodiesel production of calcium-to-aluminum molar ratio, catalyst loading, methanol-to-oil molar ratio, and reaction time was investigated. At optimal conditions, a maximum biodiesel yield (89.9%) with high purity (98.0%) was achieved and the transesterification reaction was found to follow pseudo-first-order kinetics. The optimal conditions are 1 wt% 3:1 CaO/Al2O3 calcined aerogel for reactions performed at 65 °C over 4 h using a methanol-to-oil molar ratio equal to 11:1.

Thermal effects on hydrogen storage capacity of Pd/MWCNT nanoparticles deposited at moderate pressure and temperature supercritical carbon dioxide conditions

Pd nanoparticles were deposited on MWCNT support for the first time at 80 ℃ and under 2500 psi scCO2 conditions via a bipyridyl precursor in the absence co-solvent. After deposition, the samples were heated under different atmospheres. Then their morphological and hydrogen uptake capacities were investigated. An average particle size between 7−9 nm was estimated via HR-TEM images while intense Pd(111) and Pd(200) sites were detected for all heated samples except no thermally treated one which exhibits PdHx sites. The highest hydrogen adsorption at room temperature was recorded for the samples heated under oxygen. At room temperature, Pd loading amount was found to be effective in means of captured hydrogen. Hence, at higher temperatures, hydrogen uptake of samples treated under nitrogen atmosphere was higher. Additionally, in case of the sample which was not thermally treated, a signal referring to hydrogen release between 200−300 °C during reduction was detected.

Preparation, structure, and properties of poly(ethyleneoxide)/lignin composites used for UV absorption

ABSTRACTA composite of poly(ethylene oxide) (PEO) and lignin (Lg) was prepared and characterized for its utility as an ultraviolet (UV) absorbing material. Due to the extensive UV absorption and excellent oxidation‐resistance of Lg, the formation of hydrogen bonds between the Lg particles and the PEO molecular segments renders the Lg particles well‐dispersed in the PEO matrix. PEO/Lg composites with different Lg contents show that high levels of Lg could cause defects at the PEO/Lg composite interface. The viscosities of all composites were higher than that of pure PEO. Composite foams were further prepared under supercritical carbon dioxide conditions, all of which exhibited excellent UV‐absorption properties. This work provides a means toward convenient preparation of PEO composites with UV‐absorption ability and forms a theoretical basis for the dispersion of Lg in polymer matrices. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48593.