Duration Of Synthesis Research Articles

Time-Dependent synthesis of ZnS and its influence on photocatalytic hydrogen generation

This study explores the impact of varied synthesis times on the properties and performance of zinc sulfide (ZnS) in the photocatalytic hydrogen production. Validating the synthesis of ZnS from hydrozincite, our investigation extends to diverse solvothermal synthesis durations (0.5, 5, 24 and 72 h). X-ray diffraction analyses confirm a direct correlation between synthesis time and crystallite size growth. Mesoporosity and consistent functional groups characterize all materials. Prolonged synthesis times induce ethylenediamine-Zn2+ complexes, elevating defect density and causing a red shift in materials, impacting electronic structure and reducing band gap. Paradoxically, extended synthesis times correlate with diminished hydrogen production, emphasizing the role of surface area over electronic properties in photocatalytic performance. The 05H catalyst produces an average of 2.11 times more hydrogen than 24H and 72H catalysts with a hydrogen production rate of 276 µmolg−1h−1 The study underscores the intricate interplay of parameters, providing insights into achieving optimal photocatalytic performance.

Impact of tannic acid on iron oxide nanoclusters synthesized by a polyol solvothermal method

Raspberry-shaped iron oxide nanostructures (RSNs) correspond to oriented aggregated and hollow clusters of nanograins exhibiting a high saturation magnetization and a superparamagnetic behaviour. These nanostructures are promising for a wide range of applications, such as magnetic separation, catalysis, pollution control, and nanomedicine. However, for most applications, particularly nanomedecine and depollution, high colloidal stability is required, and the isoelectric point of iron oxide is around 6–7. Therefore, these nanoclusters need to be coated with a surfactant to obtain colloidal suspensions in water. Here, we have developed a one-pot polyol solvothermal synthesis process to coat these promising nanoclusters with tannic acid (TA), a natural compound with antimicrobial properties, which has been little studied with these nanoclusters. Different parameters of the synthesis were adjusted, such as the molar ratio TA:Fe, the synthesis temperature and duration. We showed that TA interferes deeply in the RSNs synthesis mechanism with the observed reduction of iron(III) to iron(II), the complexation of TA with iron, the formation of intermediate phases, as well as the growth of a parasitic iron carbonate phase and the loss of the oriented aggregation and hollowness of the iron oxide RSNs. Considering all these parameters, the optimal synthesis conditions were thus established (TA:Fe ratio = 0.010, temperature of 200°C and duration of 10.5 h), leading to RSNs with small nanograins, a rather high surface area (82 m2/g), high saturation magnetization (74 emu/g) and good colloidal stability. By combining different characterization techniques, a new synthesis mechanism was proposed different from previously established for RSNs without TA, based on strong TA-iron oxide interfaces.

Rapid and high-throughput synthesis of rare earth molybdate materials via molten salt method

The exceptional electronic structure of rare earth molybdates renders them highly suitable for applications in photocatalysis and photoluminescence. However, currently available methods for preparing rare earth molybdates suffer from drawbacks such as inefficient yields, prolonged synthesis duration and high sintering temperatures. Here we present a novel molten salt method that facilitates rapid and high-throughput preparation of rare earth molybdate materials. This method achieved a yield of 99% for the synthesis of rare earth molybdate within a 5 h duration. An investigation into the structural and morphological characteristics of synthetic rare earth molybdate was conducted. The photocatalytic activity of Nd6MoO12 and Ln2MoO6 (Ln = La, Nd, Sm, Eu, and Gd) for Methylene blue degradation demonstrates their effective functional applications in the field of photocatalysis. The fluorescence properties of Sm3+/Eu3+-doped Gd2MoO6 demonstrate their potential applications in white light emitting diodes. These studies provide a new path to realize the synthesis of rare earth molybdate functional materials in a rapid and high-throughput manner.

Enzymatic synthesis of biologically active fructose-based saccharides by Aspergillus niger MK788296 levansucrase

Fructose-based saccharides (FBS) and levans received much attention in recent years because of their diverse biological activities and safety which help in their usability in several medical and pharmaceutical applications. In the present study, FBS and levan were synthesized by Aspergillus niger MK788296 levansucrase. Fifteen fructose-based saccharides were synthesized through the interaction between levansucrase concentration (units), duration of synthesis and substrate (sucrose) concentration through a central composite design (CCD). The synthesized FBS and levans exhibited several biological activities including prebiotic, anti-microbial, fibrinolytic, antioxidant and antitumor activities. The prebiotic effect was emphasized by its promotion effect on the growth of Bifidobacterium animalis subsp. lactis BB-12 and Lactobacillus plantarum DMS 20174. They also exerted antimicrobial activity against Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 6538. In addition, they exerted prominent antitumor activity against colorectal, liver and breast cancer cell lines.

Design rules applied to silver nanoparticles synthesis: A practical example of machine learning application.

The synthesis of silver nanoparticles with controlled physicochemical properties is essential for governing their intended functionalities and safety profiles. However, synthesis process involves multiple parameters that could influence the resulting properties. This challenge could be addressed with the development of predictive models that forecast endpoints based on key synthesis parameters. In this study, we manually extracted synthesis-related data from the literature and leveraged various machine learning algorithms. Data extraction included parameters such as reactant concentrations, experimental conditions, as well as physicochemical properties. The antibacterial efficiencies and toxicological profiles of the synthesized nanoparticles were also extracted. In a second step, based on data completeness, we employed regression algorithms to establish relationships between synthesis parameters and desired endpoints and to build predictive models. The models for core size and antibacterial efficiency were trained and validated using a cross-validation approach. Finally, the features’ impact was evaluated via Shapley values to provide insights into the contribution of features to the predictions. Factors such as synthesis duration, scale of synthesis and the choice of capping agents emerged as the most significant predictors. This study demonstrated the potential of machine learning to aid in the rational design of synthesis process and paves the way for the safe-by-design principles development by providing insights into the optimization of the synthesis process to achieve the desired properties. Finally, this study provides a valuable dataset compiled from literature sources with significant time and effort from multiple researchers. Access to such datasets notably aids computational advances in the field of nanotechnology.

Preparation of hydrophilic MgAl type layered double hydroxide films with elevated Mg/Al molar ratio on aluminum substrates via a facile approach

A straightforward method is necessary for synthesizing hydrophilic films on aluminum fins and heat sinks intended for water vaporization-based cooling applications. Herein, a facile synthesis approach is presented for generating hydrophilic films of MgAl type layered double hydroxides (LDH) at temperatures of 20 and 50 °C, with a synthesis duration of less than 120 min. The synthesized films were comprehensively characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, and field emission scanning electron microscopy. The film hydrophilicity was assessed through contact angle (CA) measurements with water. XRD analysis revealed a higher intensity of LDH film peaks at 50 °C than at 20 °C. Additionally, the Mg/Al and Cl/Al ratios within the films increased with increasing concentrations of MgCl2. Notably, chloride anions constituted approximately 70–80% of the anions in the LDH films, with the remaining 20–30% expected to be CO32−. The surface morphology of the films displayed net-like and porous flower-like structures, which varied based on the synthesis conditions. The hydrophilicity of the LDH films was found to be more strongly influenced by the Mg/Al molar ratio than by the surface morphology. Particularly, the CA test indicated a hydrophilicity threshold at a Mg/Al molar ratio of approximately 2.0, with a CA of 0° when the molar ratio exceeded 2. The resultant hydrophilic film on aluminum is potentially applicable to vaporization-type coolers.

Application of Taguchi orthogonal array in optimization of the synthesis and crystallinity of metal organic framework 5 (MOF 5)

Purpose: To use the L25 Taguchi orthogonal array for optimizing the three main solvothermal parameters that affect the synthesis of metal-organic frameworks-5 (MOF-5).
 Methods: The L25 Taguchi methodology was used to study various parameters that affect the degree of crystallinity (DOC) of MOF-5. The parameters comprised temperature of synthesis, duration of synthesis, and ratio of the solvent, N,N-dimethyl formamide (DMF) to reactants. For each parameter, the volume of DMF was varied while keeping the weight of reactants constant. The weights of 1,4-benzodicarboxylate (BDC) and Zn(NO3)2.6H2O used were 0.390 g and 2.166 g, respectively. For each parameter investigated, five different levels were used. The MOF-5 samples were synthesized using the solvothermal reaction method, and successful synthesis was confirmed with x-ray diffraction (XRD), microscopy, Fourier transform infrared spectroscopy (FTIR) and energy-dispersive x-ray spectroscopy (EDS). The DOC obtained via XRD served as a parameter of objective quality.
 Results: The optimum conditions that gave the highest DOC were synthesis temperature of 130 °C, duration of 60 h, and a vehicle volume of 50 mL, with optimum Brunauer-Emmett-Teller surface area (BET -SA) of 800 m2/g. All the three synthesis parameters significantly influenced the DOC of the synthesized MOF-5 (p < 0.05). Sub-optimal conditions resulted in distorted MOFs, products that deviated from MOF-5 specifications, or MOF-5 with low DOC.
 Conclusion: Based on DOC and BET-SA, the best conditions for synthesis of MOF-5 when using Taguchi OA, were temperature of 130 °C, duration of 60 h, and a DMF volume of 50 mL.

Cementless concretes, based on anthropogenic wastes of the Irkutsk Oblast

The accepted global trend of transition from a linear economy to a closed-loop one stimulated the development of regulatory documents, such as “Strategy for the development of building materials in the Russian Federation and Irkutsk Oblast”, Decree of the Government of the Russian Federation dated 08/02/2023 No. 2094, both at federal and regional levels. Further, the Baikal interregional scientific and educational centre was established. All this aims at obtaining technologies for developing effective building materials, based on technogenic wastes, and establishing the production. It is planned to obtain effective building materials, based on the accumulated high-tonnage waste of the Usolye-Sibirskoye priority development area, such as ash and slag mixtures of the combined heat and power plant (90 million tons) and lime-containing waste, generated during the production of acetylene at the Khimprom PJSC (more than nine million tons). The paper represents a fundamentally new approach to obtaining artificially synthesised newgrowths of cementless concrete, based on technogenic wastes, which meets the requirements of regulatory standards in terms of frost and water resistance and allows using this concrete in enclosing structures. At a rationally selected ratio between lime-containing wastes and an ash-slag mixture, subject to the pre-established principles of technological preparation in terms of their mechanical activation, mixing technology, conditions and synthesis duration, it is possible to obtain high-quality cementless concrete that meets the basic requirements of regulatory documents for quality indicators.

Polydopamine-mediated in situ synthesis of gold nanoparticles uniformly distributed on silk fibers as reusable catalysts for efficient 4-nitrophenol reduction

Developing green fibrous materials with uniformly distributed metal nanoparticles for highly efficient and recyclable catalysis remains a major challenge. Herein, we developed a simple, effective, and green method to immobilize gold nanoparticles (AuNPs) on polydopamine (PDA)-functionalized silk fibers (SFs) for efficient catalytic reduction of 4-nitrophenol (4-NP). The density and size of AuNPs on the PDA-coated SFs can be tuned by adjusting precursor concentration and synthesis duration, respectively. The AuNPs-PDA-SFs catalysts prepared under optimized conditions could catalyze the reduction of 4-NP, 4-nitroaniline (4-NA), and 4-amino-3-nitrophenol (4-A-3-NP) at the apparent rate constants of 0.087, 0.091, and 0.063 min−1, respectively. After six rounds of flow-through reduction of 4-NP, the AuNPs-PDA-SFs could maintain a 4-NP conversion rate greater than 92%, indicating their superior reusability and consistent catalytic activity. Due to the protein properties of SFs, the AuNPs-PDA-SFs can be degraded by enzymes and alkali solutions. This work may provide new insights for designing advanced fiber-supported recyclable catalysts with high catalytic performance and reusability in wastewater treatment.

SYNTHESIS OF FIRE RETARDANT WITH PHOSPHORUS AND METAL FOR PRESERVATION AND REACH OF REDUCTION OF FLAMMABILITY OF TEXTILE MATERIALS

In this article, the optimal conditions for synthesizing a new flame retardant based on pentaerythritol, phosphoric acid, and magnesium hydroxide are studied. In this case, the molar ratio of the initial substances was 3.64:1, and the synthesis duration was four hours. After the completion of this process, different (1, 3, and 5%) solutions of magnesium hydroxide were added at a temperature of 90 ºC for 3 hours. The yield of this reaction was 85%. Applying this obtained flame retardant to textile materials increases the fire resistance of textile materials. The composition of synthesized antiperine and antiperine applied textile fabrics was studied by IR spectrum, and the thermal decomposition of antiperine applied fabric was investigated by TGA and DTA analysis, and 100 μm sections of flame retardant treated fabrics were measured by scanning electron microscope. The fire resistance and physical mechanical properties of these materials were studied based on the requirements of GOST 50810-95. The oxygen index of the fabric treated with synthesized flame retardant was 35.6%.

The impact of pH and temperature on the green gold nanoparticles preparation using Jeju Hallabong peel extract for biomedical applications.

The utilization of gold nanoparticles (AuNPs) has garnered significant attention in recent times, particularly in the field of biomedical research. The utilization of AuNPs in chemical synthesis procedures raises apprehensions regarding their potential toxicity in living organisms, which is inconsistent with their purported eco-friendly and cost-effective aspects. In this investigation, AuNPs were synthesized via the green synthesis approach utilizing Jeju Hallabong peel extract (HPE), a typical fruit variety indigenous to South Korea. The visible-range absorption spectrum of gold nanoparticles from green synthesis (HAuNPs) that are red wine in color occurs at a wavelength of λ = 517 nm. The morphology and particle size distribution were analysed using transmission electron microscopy (TEM) and ImageJ software. The TEM images reveal that the HAuNPs exhibit a high degree of dispersion and uniformity in their spherical shape, with an average size of approximately 7 nm. Moreover, elevating the initial pH level of the mixed solution has an impact on the decrease in particle dimensions, as evidenced by the blue shift observed in the UV-visible spectroscopy absorbance peak. Elevating the reaction temperature may accelerate the synthesis duration. However, it does not exert a substantial impact on the particle dimensions. The outcomes of an avidin-biocytin colorimetric assay provide preliminary analyses of possible sensor tunability using HAuNPs. The cytotoxicity of HAuNPs was evaluated through in vitro studies using the MTT assay on RAW 264.7 cell lines. The results indicated that the HAuNPs exhibited lower cytotoxicity compared to both chemically reduced gold nanoparticles (CAuNPs).

Challenges of Scaling-up the Wet-Chemical Synthesis of β-Li3PS4

All-solid-state batteries are considered the next generation in battery technology due to increased energy and power density as well as freedom of design, e.g. by constructing batteries in bipolar stacks. Solid-state electrolytes offer advantages over conventional liquid electrolytes, such as greater thermal safety, because of high melting points, and higher mechanical strength. This is believed to suppress growth of lithium dendrites and, therefore, opens up the possibility of using a lithium metal anode. One promising material group is sulfides, because they are ductile and have a good intrinsic ionic conductivity. Some sulfide solid electrolytes can be synthesized wet-chemically. This offers advantages like tailoring the particle size, working at ambient temperatures, short synthesis durations, stabilizing meta-stable phases by using new synthesis routes and the possibility of transferring the routine to a continuous process. The particle size and morphology are important factors regarding the suitability to produce all-solid-state batteries wherefore small (< 10 µm) and homogeneous particles are preferred. The present research mainly focusses on finding and improving new materials and their usage in battery production, but there is little progress on mass-production of sulfide solid electrolytes. To scale-up a synthesis, multiple aspects have to be considered since they often influence both product and process. Therefore, an analysis and optimization of the synthesis process is necessary to support the development and to increase the economic attractiveness of new materials.In this presentation, the reaction enthalpy and the influences of concentration and solvent variation of synthesizing the sulfide solid electrolyte β-Li3PS4 are examined and discussed. β-Li3PS4 is synthesized by mixing lithium sulfide and phosphorus pentasulfide in a solvent, e.g. THF, at ambient conditions. After removing the solvent, heat treatment is used to obtain the crystalline product. We found that the mixing step contains a highly exothermic reaction and determined the reaction enthalpies using a reaction calorimeter. To handle the heat development, two options were investigated: First, the solvent amount was increased and second, the synthesis was performed using alternative solvents with different thermal properties. The examined solvents are THF, ethyl acetate and ethyl propionate. The reaction enthalpies of the synthesis in different solvents are compared. A strong influence on the particle size and morphology caused by the amount and choice of solvent could be detected by SEM. While the particle size increases with increasing amount of solvent, the shape of the particles alters under solvent variation. With low solvent amount the smallest particle sizes (< 10 µm) are synthesized. Finally, suggestions regarding the scale-up will be given based on the findings of these examinations.

ESTERIFICATION OF BETULIN 3-ACETATE IN MELTS OF THE MALEIC AND LEVULINIC ACIDS

Esters of betulin containing residues of bioactive aromatic and aliphatic acids are of interest to the chemical and pharmaceutical industry as hepatoprotectors, anti-inflammatory, antiulcer and immunomodulatory substances. The development of new efficient, ecological and economical methods for the synthesis of betulin esters is an actual task. A new "green" method for the production of betulin 3-acetate-28-maleate and betulin 3-acetate-28-levulinate has been developed. For the first time, esterification of betulin 3-acetate with melts of maleic acid and levulinic acids was carried out at a temperature of 185-200°C for 5-7 minutes to obtain betulin 3-acetate-28-maleate and betulin 3-acetate-28-levulinate, respectively. The structure of the resulting betulin esters was determined using IR and NMR spectroscopy, and the composition was determined by elemental analysis. The advantage of the developed method for the synthesis of 3-acetate-28-maleate and 3-acetate-28-levulinate of betulin in comparison with the known ones is: the synthesis is carried out in the absence of harmful and hazardous solvents (pyridine, methylene chloride, chloroform), a reduction in the duration of synthesis from 15-40 hours to 5-7 minutes. Maleic anhydride is used instead of maleic anhydride on the preparation of betulin 3-acetate-28-maleate.

Fast and facile pH tailored green synthesized ZnO photocatalyst by biogenic reduction using water extract of Averrhoa bilimbi (L) fruit

Abstract The present study reports an economical and environmentally friendly technique for the synthesis of zinc oxide nanoparticles. The water extract of Averrhoa bilimbi (L) fruit was used in this one-pot synthesis approach for ZnO nanoparticle reduction and stabilisation. Varied size, shape and properties of the synthesized nanomaterials were obtained by tuning the pH of the synthesis medium. X-ray diffraction techniques, diffuse reflectance spectroscopy, photoluminescence and scanning electron microscopy analysis were used for characterizing phytochemical capped ZnO nanoparticles. The morphological change with varying pH was observed from scanning electron microscopy images. Short duration of synthesis with high yield product at ambient room temperature are the salient features of this procedure. The synthesised ZnO nanoparticles showed excellent photocatalytic activity and superhydrophilicity to be used in a wide range of applications.

ВЛИЯНИЕ ДЛИТЕЛЬНОСТИ МЕХАНОХИМИЧЕСКОГО СИНТЕЗА НА СТРУКТУРНО-МОРФОЛОГИЧЕСКИЕ ХАРАКТЕРИСТИКИ СИЛИКАТ-КАЛЬЦИЕВОЙ ДИСПЕРСИИ

Mechanochemical synthesis of sucrose-modified calcium hydrosilicates as precursors of calcium silicate dispersions – polyfunctional additives for cement systems was carried out on a fine grinding vibromill VM-20. The influence of duration of mechanochemical synthesis of modified hydrosilicates on the phase composition of calcium silicate dispersions, morpho-structural characteristics of the nanostructured calcium silicate xerogel particles, as well as technological features of the reaction mass of mechanochemical synthesis was studied. It was found that the viscosity of the reaction mass of mechanochemical synthesis changes non-monotonically during synthesis: in the first 2 hours of mechanochemical synthesis, the viscosity decreases; subsequently, the viscosity of the mixture increases slightly; the reaction mass maintains high fluidity throughout the entire synthesis process; the presence of raw mineral materials in the reaction mass continues to be fixed throughout the synthesis (up to 7 hours); recrystallization processes of synthesized weakly crystallized phases are activated after 6 hours of grinding.&#x0D; The volume of the synthesized xerogel was estimated from the specific surface area of the calcium silicate dispersion. It was found that the processes of recrystallization of weakly crystallized phases synthesized during mechanochemical synthesis do not affect the volume of xerogel in the composition of calcium silicate dispersion, the specific surface area of the calcium silicate dispersion increases in proportion to the duration of the mechanochemical synthesis of modified calcium hydrosilicates. The duration of mechanochemical synthesis does not affect the morpho-structural characteristics of coagulation xerogel particles.

Features of Structures and Ionic Conductivity of Na3Fe2(PO4)3 Polycrystals Obtained by Solid Phase and Melt Methods

This article investigates the structures and conductive properties of polycrystals of Na3Fe2(PO4)3 obtained by solid-state and melt synthesis methods using concentrated optical radiation. It has been established that in the melt synthesis method, the material is synthesized under significantly non-equilibrium thermodynamic conditions, leading to the creation of deformations in the sample, which contribute to the enhancement of ionic conductivity. Additionally, the synthesis duration is reduced by half. Through a comparative assessment of the structural parameters and conductive properties of these materials, it is demonstrated that polycrystals obtained by the melt method exhibit better texture and higher ionic conductivity. The occurrence of deformations during the synthesis of α-Na3Fe2(PO4)3 under high temperature-gradient conditions indicates the elasticity of the crystalline framework {[Fe2(PO4)]3−}3∞. It is concluded that the non-equilibrium thermodynamic conditions of α-Na3Fe2(PO4)3 synthesis promote the formation of deformations in the crystalline structure of polycrystals, leading to a partial increase in symmetry and ionic conductivity.

The Growth Mechanism, Luminescence, and Lasing of Polyhedral ZnO Microcrystals with Whispering-Gallery Modes

This work studies the features of the formation of isometric polyhedral ZnO microcrystals that provide stimulated emission and whispering-gallery-mode (WGM) lasing in the near-UV range. For this purpose, the growth stages of such crystals in the process of gas-transport synthesis and the luminescent properties of the structures obtained at each stage were investigated. It was shown that the growth of laser microcrystals begins with the formation of microspheroids with thin ZnO shells. Such spheroids exhibit mainly white luminescence with a small contribution of near-UV emission. Increasing the synthesis duration results in thickening and faceting of the spheroid shells, as well as a decrease in the contribution of the yellow–red component to the luminescence spectrum. At the same time, ZnO microcrystallites nucleate and grow inside the spheroids, using as a material the remains of a liquid zinc drop and oxygen entering the spheroids through their shells. Such growth conditions allow them to take on an equilibrium polyhedral shape. Eventually, upon destruction of the spheroid shell, a polyhedral ZnO microcrystal supporting WGMs is observed.

Analysis of the Degree of Crystallinity of Aluminosilicates of the Kaolinite Subgroup According to the IR Spectroscopy Data

The data of X-ray diffraction and IR spectroscopy of synthetic aluminosilicates of the kaolinite subgroup with different degrees of crystallinity are analyzed. The samples are obtained under hydrothermal conditions in alkaline and neutral media with different durations of synthesis. It is shown that as the synthesis time increases a gradual transition of the amorphous phase to the crystalline phase is observed, which is reflected in the IR spectra by the shift of the bands related to the oscillations of the groups in the octahedral and tetrahedral grids. The first band of stretching vibrations of hydroxyl groups at 3628 cm–1 appears after three days of hydrothermal treatment in a neutral medium, and under alkaline conditions with the same duration of treatment, two more bands are observed at 3687 and 3668 cm–1. The detected changes in the IR spectra correspond to the appearance of the characteristic X-ray reflections of halloysite according to the XRD data. Thus, IR spectroscopy can be considered as a method for a qualitative assessment of the degree of crystallinity.

Studying the influence of duration of mechanochemical synthesis of nanostructured (Fe, Ti)3 Al powder on characteristics of plasma coatings

Studying the influence of duration of mechanochemical synthesis of nanostructured (Fe, Ti)3 Al powder on characteristics of plasma coatings

Highly efficient cellular expression of circular mRNA enables prolonged protein expression

A major problem with mRNA therapeutics is that mRNA is usually degraded within a few hours after entering the cytosol. New approaches for invitro synthesis of circular mRNA have allowed increased levels and duration of protein synthesis from mRNA therapeutics due to the long half-life of circular mRNA. However, it remains difficult to genetically encode circular mRNAs in mammalian cells. Here, we describe the adaptation of the Tornado (Twister-optimized RNA for durable overexpression) system to achieve in-cell synthesis of circular mRNAs. We screen different promoters and internal ribosomal entry sites (IRESs) and identify combinations that result in high levels of circular mRNA and protein expression. We show that these circular mRNAs can be packaged into virus-like particles (VLPs), thus enabling prolonged protein expression. Overall, these data describe a platform for synthesis of circular mRNAs and how these circular mRNAs can improve VLP therapeutics.