Amount Of PVP Research Articles

Green and facile synthesis of OH-functionalized UiO-66 with controlled particle sizes to improve the selective separation of CO2/N2

The escalating levels of carbon dioxide in flue gas and the resultant greenhouse effect have heightened the need for adsorbents with high CO2 sorption and separation capabilities. However, Traditional heated synthesis methods are energy-intensive and often involve toxic solvents, which are not viable for widespread industrial use. This study introduces a room-temperature, eco-friendly synthesis technique to produce UiO-66-(OH)2 with varying amounts of PVP (0/0.1/0.2 g), effectively adjusting the particle morphology. Results confirm that this method maintains robust CO2 adsorption and selectivity. Notably, the addition of 0.1 g of PVP led to a reduction in pore size and adsorption capacity of CO2, yet remarkably enhanced its CO2/N2 separation performance sixfold, outperforming traditional CO2 adsorbents. Dynamic breakthrough experiments further validated the effectiveness of UiO-66-(OH)2 in separating binary mixtures of CO2/N2 (v/v = 15/85).

PVP−I Catalyzed Oxidation of N‐substituted Benzylamines to Benzamides

AbstractAn oxidative transformation from N‐substituted benzylamine into the corresponding benzamides was developed here using the oxidative system combined from the catalytic amount of PVP−I (polyinyl pyrrolidone) with TBHP. This newly developed method had the advantages of mild reaction conditions and broad substrate scope. The key intermediate of Enzalutamide as androgen receptor inhibitors was prepared using this catalytic condition starting from commercial available 2‐fluoro‐4‐nitrobenzaldehyde with the yield of 78.5 % for three‐step reactions.

Fabrication and Characterization of Chitosan-Polyvinyl Pyrolidone K-30 for Creatinine Transport Membranes

The investigation of membrane-based hemodialysis is an interesting study due to its efficacy in eliminating metabolic waste compounds, such as creatinine, from the body. However, not all membrane types exhibit optimal transport capabilities, necessitating modifications. In this study, we conducted modifications on chitosan (CS) membranes by incorporating polyvinyl pyrrolidone K-30 (PVP K-30) and assessing their physicochemical characteristics. The modified membrane underwent characterization and subsequent evaluation of its transport capabilities. The primary objective of this research is to design a membrane composed of chitosan and PVP K-30 with enhanced creatinine transport capabilities. The study commenced with the fabrication of CS membranes combined with CS-PVP, involving six variations of CS and PVP K-30 with volume ratios of 5:0, 4:1, 3:2, 1:1, 2:3, and 4:1. The resulting solution was then printed into a flat sheet membrane. All completed membranes underwent comprehensive characterization, including tests for functional groups using Fourier Transform Infrared (FTIR), membrane weight and thickness, porosity, water absorption, swelling, hydrophilicity, pH resistance, and biodegradation. In the final phase, the membrane was utilized in the creatinine transport process. FTIR analysis of the CS-PVP K-30 membrane revealed O-H and N-H group spectra at wave numbers 3363.06 cm-1 and 1587.17 cm-1, indicating hydrogen bonding between the two polymers. Characterization tests demonstrated that the CS-PVP membrane exhibited increased porosity, water absorption, swelling, and hydrophilicity. In the creatinine transport test, the CS-PVP membrane demonstrated enhanced creatinine transport ability compared to the CS membrane. The highest clearance value for creatinine was observed in the CS-PVP5 membrane, with an increase in the amount of PVP K-30 correlating with an elevated creatinine clearance value. The creatinine clearance values for the CS membrane, CS-PVP1, CS-PVP2, CS-PVP3, CS-PVP4, and CS-PVP5 were 0.30, 0.36, 0.37, 0.39, 0.42, and 0.46 mg/dL, respectively.

Pelletizing highly porous covalent triazine framework under mild conditions and applying it as adsorbent for Ru3+ ions

CTFs (Covalent triazine frameworks) exhibit exceptional porosity and the ability to incorporate hetero-atoms (e.g. Ru) into their microstructures makes them versatile for several applications. However, pelletized form of the catalysts is required for various industrial processes. Although there are several methods available for pelletizing catalysts, but porosity of the pelletized CTF particles is compromised by applying these processes. In this study, CTF was synthesized by polymerizing Terephthalonitrile (TN) and pelletizing it by using Polystyrene (PS) and PVP. In CTF-PS composites, CTF particles were interconnected by PS microfibers with thickness ranging from 3 to 230 μm, while PVP and CTF were bonded by weak Van der Waals bonding. BET analysis showed Type-I isotherms for CTF-PS, and CTF-PVP composites, indicating that the materials were typically microporous, with an average pore size of ∼2 nm. Surface area values for the CTF-PVP, and CTF-PS were measured as 1128.7, and 610.81 m2g-1, meanwhile, pore volumes for the same were recorded as 0.532, and 0.291 cm3g-1, respectively. Owing to the small amount (10 %) of PVP in its composites CTF-PVP pellets retained most of the pores, maintaining almost 80 % of the porosity but could not remain intact in protic solvents. However, the CTF-PS pellet demonstrated excellent stability in protic solvents, making it suitable for support for the Ru catalyst or Ru extraction from solution. At 60 °C, by using 500 μM solution of RuCl3.3H2O 26 % of Ru was attached to the CTF-PS pellet, which can be an excellent prospect for lab scale catalytic reaction or industrial application.

Shape-dependent synthesis and photocatalytic degradation by Cu2O nanocrystals: Kinetics and photocatalytic mechanism

In this study, Cu2O crystals with different morphologies were synthesized to investigate the effect of exposed crystalline facets on photocatalytic degradation efficiency. By adjusting the addition amount of PVP, different morphologies of Cu2O crystals were obtained, such as cubic, decahedral, octahedral, etc. XRD, SEM, and TEM characterizations were used to observe the properties of the synthesized Cu2O in terms of morphology, size, and lattice structure. The results showed that the octahedral cuprous oxide had the strongest photocatalytic degradation effect (78.3%). The study also explored the connection between different crystalline facets and MO microstructure, and the effect of crystalline facet selectivity on the pre-absorption and photocatalytic degradation of MO. Density Functional Theory (DFT) calculations were used to investigate the connection between the energy level structure of different crystalline facets of Cu2O and its photocatalytic activity. Finally, based on the experimental analysis and theoretical calculation, a new charge separation model on crystalline surface was proposed.

Superior diffusion dialysis anion exchange membranes from miscible polyether sulfone – poly(vinyl pyrrolidone-co-styrene) blends

Diffusion dialysis is a promising method for the recovery of titania waste acid due to its low energy consumption and ease of operation. However, the current commercial anion exchange membranes (AEMs) suffer from low acid permeability coefficient and high cost. To address this issue, the development of high-performance AEMs is crucial for the successful recovery of titania waste acid by diffusion dialysis. Previous studies [Journal of Membrane Science, 2022, 662, 120980] have shown that the dense polyether sulfone - poly(vinyl pyrrolidone) (PES-PVP) blend membranes can be converted into AEMs through the protonation reaction of the O atoms in pyrrolidone with H+ in sulfuric acid solution. This process enables the efficient separation of sulfuric acid from ferrous sulfate. The acid permeability coefficient of the blend membrane is influenced by the content and molecular weight of PVP. Higher content and molecular weight of PVP result in a greater acid permeability coefficient of the membranes. It is observed that due to the water solubility of PVP, the amount of PVP added to the blend membranes cannot exceed 60%, however this would restrict further improvement in the acid permeability coefficient of the membranes. Additionally, there is a concern regarding the long-term stability of the membranes as the PVP may get washed out from the membranes. To this, P(VP-co-St) copolymers with a certain hydrophobicity are synthesized through free radical copolymerization of hydrophilic monomer N-vinylpyrrolidone (VP) and hydrophobic monomer styrene (St). PES-P(VP-co-St) dense membranes are then prepared by mixing the P(VP-co-St) copolymers with PES. The objective of this study is to investigate the effects of P(VP-co-St) molecular weight, VP content, and composition of the casting solution on the physicochemical properties, mass transfer properties, and stability of the blend AEMs. The results show that homogeneous dense membranes can be prepared by completely mixing PES with P(VP-co-St) copolymers with 87–90 wt% VP content and 100–150 kDa molecular weight. The permeability coefficients of H2SO4 (PH2SO4) and FeSO4 (PFeSO4) increase with the VP content in the membrane phase. The ion exchange capacity of the PES-P(VP-co-St)-1# AEM varies in the range of 0.32–0.81 mmol/g dry membrane. For the PES-P(VP-co-St) blend membranes, synthesized by blending P(VP-co-St) with 90 wt% VP content with PES at a mass ratio of 7:3 (VP content of 61 wt% in the membranes), the PH2SO4, PFeSO4, and selectivity coefficient of the membranes are 692 × 10−9 m2/h, 5.8 × 10−9 m2/h, and 119, respectively. The PH2SO4 of the PES-P(VP-co-St) AEM is much higher than that of the commercial AEM Tianwei DF-120 while maintaining high selectivity. This study successfully develops AEMs with high performance in diffusion dialysis through a convenient method by blending P(VP-co-St) copolymers with PES.

Mechanistic consideration of ZnTe microspheres formation in a PVP-contained polyol system via hot injection method

Zinc telluride (ZnTe) microspheres have been synthesized in a polyol system with adding various amount of poly(N-vinyl-2-pyrrolidone) (PVP, K-90) at 200 °C via a hot injection method. The smallest sized ZnTe microspheres obtained in this study had an average size of 634 nm through reaction for 48 h using 518 mg of PVP. A retrospective study was conducted to evaluate the formation process of ZnTe microspheres by conducting experiments from 0.2 h to 48 h. Nucleation and growth of ZnTe at the tips of Te rods in a PVP-contained polyol system were observed in sample reacted less than 1 h. More ZnTe microspheres and less Te rods were observed when the reaction was proceeded for longer time, suggesting that Te rods were the sacrificial template for the growth of ZnTe. Amount of PVP is the key factor of controlling dimensions of Te rods formed at the initial stage as well as the sizes of ZnTe microspheres by influencing the nucleation and growth rate of ZnTe. The obtained ZnTe microspheres at 48 h consisted of voids, which were originated by the detachment of ZnTe microspheres from Te rods after their growth.

Fabrications of Electrospun Mesoporous TiO2 Nanofibers with Various Amounts of PVP and Photocatalytic Properties on Methylene Blue (MB) Photodegradation.

The superior chemical and electrical properties of TiO2 are considered to be suitable material for various applications, such as photoelectrodes, photocatalysts, and semiconductor gas sensors; however, it is difficult to commercialize the applications due to their low photoelectric conversion efficiency. Various solutions have been suggested and among them, the increase of active sites through surface modification is one of the most studied methods. A porous nanostructure with a large specific surface area is an attractive solution to increasing active sites, and in the electrospinning process, mesoporous nanofibers can be obtained by controlling the composition of the precursor solution. This study successfully carried out surface modification of TiO2 nanofibers by mixing polyvinylpyrrolidone with different molecular weights and using diisopropyl azodicarboxylate (DIPA). The morphology and crystallographic properties of the TiO2 samples were analyzed using a field emission electron microscope and X-ray diffraction method. The specific surface area and pore properties of the nanofiber samples were compared using the Brunauer-Emmett-Teller method. The TiO2 nanofibers fabricated by the precursor with K-30 polyvinyl pyrrolidone and diisopropyl azodicarboxylate were more porous than the TiO2 nanofibers without them. The modified nanofibers with K-30 and DIPA had a photocatalytic efficiency of 150% compared to TiO2 nanofibers. Their X-ray diffraction patterns revealed anatase peaks. The average crystallite size of the modified nanofibers was calculated to be 6.27-9.27 nm, and the specific surface area was 23.5-27.4 m2/g, which was more than 150% larger than the 17.2 m2/g of ordinary TiO2 nanofibers.

Continuous Patterning of Silver Nanowire-Polyvinylpyrrolidone Composite Transparent Conductive Film by a Roll-to-Roll Selective Calendering Process

The roll-to-roll (R2R) continuous patterning of silver nanowire-polyvinylpyrrolidone (Ag NW-PVP) composite transparent conductive film (cTCF) is demonstrated in this work by means of slot-die coating followed by selective calendering. The Ag NWs were synthesized by the polyol method, and adequately washed to leave an appropriate amount of PVP to act as a capping agent and dispersant. The as-coated Ag NW-PVP composite film had low electronic conductivity due to the lack of percolation path, which was greatly improved by the calendering process. Moreover, the dispersion of Ag NWs was analyzed with addition of PVP in terms of density and molecular weight. The excellent dispersion led to uniform distribution of Ag NWs in a cTCF. The continuous patterning was conducted using an embossed pattern roll to perform selective calendering. To evaluate the capability of the calendering process, various line widths and spacing patterns were investigated. The minimum pattern dimensions achievable were determined to be a line width of 0.1 mm and a line spacing of 1 mm. Finally, continuous patterning using selective calendering was applied to the fabrication of a flexible heater and a resistive touch sensing panel as flexible electronic devices to demonstrate its versatility.

Wheat gluten hydrolysates with embedded Ag-nanoparticles; a structure-function assessment for potential applications as wound sorbents with antimicrobial properties

Numerous approaches have been used to prevent bacterial infection from injured skin, such as bandages and topical creams. However, the higher level of reactive oxygen species, bacterial infections, and excess wound exudates remain the major challenges for wound healing. In this study, we have tailored the structure of wheat gluten hydrolysates (WGH) as a continuous matrix by compositing it with a minimal amount of PVA, PVP, and PEG as polymer crosslinkers (0.5 wt%) to provide film structure integrity. Silver nanoparticles (AgNPs) were impregnated into the WGH to develop a control release matrix of the AgNPs. Scanning electron microscopy, X-ray diffractogram, and functional group patterns of WG and AgNPs indicate a successful integration of AgNPs into the wheat gluten matrix. The swelling capacity of the films was tested at acidic, neutral, and basic pH and was found to be highest in WG/PEG/Ag at pH 9 with 389%. The gradual release of Ag+/AgNPs from the films significantly scavenged free radicals and increased the antibacterial activity with up to a 12 mm inhibition zone against Pseudomonas aeruginosa. According to these findings, WGH with AgNPs has been successfully cast in films with increased absorption capacity, free radicals scavenging, oxidant quenching, and antibacterial capabilities, along with the sustained release of silver ions. The results, therefore, show the potential of the developed films in biomedical applications such as wound dressing.

Clarification of the dispersion mechanism of three typical chemical dispersants in lithium-ion battery (LIB) slurry

This paper mainly clarified the dispersion mechanism of three typical chemical dispersants which are polyethylene glycol octylphenyl ether (Triton X-100, T-100), polyethylene pyrrolidone (PVP) and carboxymethyl cellulose (CMC) within lithium-ion battery (LIB) slurry. Initially, the optimum amounts of T-100, PVP and CMC are selected from 0%, 0.5%, 1.5% and 2.5% by evaluating the impedance of LIB slurry in the case of adding each typical chemical dispersant with EIS method. Moreover, the impedance spectrum of three different slurry samples which are PVDF-NMP solution, LiCoO2 slurry and Carbon Black (CB) slurry with the optimum amount of each dispersant are also investigated. After using SEM and C element distribution images of LIB slurry to verify the correctness of the dispersion mechanism of each dispersant, it is concluded that the dispersion CMC with its optimum amount 1.5% is the best one to promote the formation of conductive paths and CB-coated LiCoO2 network structure within LIB slurry, which has the considerably potential to improve the performance of LIB.

High adsorption and photocatalytic degradation abilities of amorphous Ta2O5 nanospheres under simulated solar light irradiation

In this study, the crystallized and amorphous Ta2O5 nanospheres were successfully synthesized by a simple alcohol-thermal reaction. The particle sizes of amorphous Ta2O5 nanospheres were controlled by adjusting the PVP amount in the synthetic system. The removal abilities of the Ta2O5 towards organic dyes were assessed by measuring the adsorption and the photocatalytic degradation performance towards methylene blue (MB) under dark condition and simulated solar light irradiation, respectively. The results indicate that the amorphous Ta2O5 prepared with 1:5 PVP (a-Ta2O5 5PVP) exhibited extremely high adsorption abilities and photocatalytic degradation performances, compared to the crystallized and other amorphous Ta2O5 nanospheres. The excellent MB removal ability of a-Ta2O5 5PVP can be attributed to high specific surface area, extra O vacancies, enhanced visible light absorption, more photo-generated electrons and low charge transfer resistance. This study may shed light on a simple but low-cost preparation strategy for amorphous Ta2O5 nanospheres suitable for the future practical application on wastewater treatment and provide deep insights on the underlying reasons for the high removal performance to organic dyes.

Comparative Study on Elution of Polyvinylpyrrolidone on Dialyzers Using Ultraviolet Analysis and Iodine Method.

It is known that poly(arylethersulfone)-based dialyzers can elute poly( N -vinyl-2-pyrrolidone) (PVP). With regard to chronic renal replacement therapy, this is a burden for the patient, because PVP is deposited in different organs and cannot be degraded or released from there; so elutable PVP has to be minimized. Usually, the iodine method is used for quantification of extractable PVP. To overcome the chain length dependency of this method, we used an ultraviolet method that is independent from the PVP chain lengths; so the absolute amount of eluted PVP can be quantified. The current study shows the amount of eluted PVP on differently sterilized low flux dialyzers (1.6 m 2 , similar storage time, n = 12)-PS160 (Allmed, Egypt), F7HPS (Fresenius Medical Care, Germany), F16 (Wego, China), and B-16P (Bain, China). Using the ultraviolet method, the irradiated filters show a sum total of approximately 9 mg more eluted PVP compared with the steam-sterilized ones, whereas the iodine method shows a value about three times lower between different types of sterilization. The boundary conditions during the radiation sterilization could lead to PVP degradation instead of cross-linking. The resulting shorter PVP chains can be more easily rinsed out and can falsely decrease the calculated eluted PVP amount by using the iodine complexation method.

PVP-Assisted Hydrothermal Synthesis of Bi2O2Se Nanosheets for Self-Powered Photodetector

Abstract: Bi2O2Se nanosheets were successfully synthesized via a facile one-step PVP-assisted hydrothermal process for the first time. Corresponding characterizations, such as XRD, XPS, SEM and TEM, were carried out to investigate the formation of the products on the amount of PVP in the reaction system. Results revealed that the single-crystalline Bi2O2Se nanosheets with small mean lateral size of 176.3 nm were obtained when the amount of PVP is 0.75 g. Single-crystalline Bi2O2Se nanosheets self-powered photodetector exhibited excellent photodetection performance, superior to that of self-powered photodetectors based on the products synthesized without PVP and other nanomaterials. Under the illumination of 365 nm ultraviolet light, the rise time, responsivity and detectivity could approach up to 9 ms, 14.24 mA/W and 3.16×108 Jones, respectively. Bi2O2Se devices have high photoresponse even in the visible and near infrared bands due to its suitable band gap. The present work provides a novel preparation route of Bi2O2Se via hydrothermal method and PVP assisted synthesis of Bi2O2Se nanosheets is reported for the first time. Bi2O2Se nanosheets self-powered photodetector exhibited excellent photodetection performance and points out a direction for the evolution of self-powered photodetectors in the in the future.

Green and facile synthesis of EuBDC coordination polymer: Effects of ultrasound and stabilizing agent on morphological, structural and photophysical properties

In this study, a facile, green and fast method to produce the coordination polymer (CP) EuBDC is proposed for the first time using a stabilizing agent and ultrasonic irradiation. The crystal structure was investigated by XRD crystallography and it was demonstrated that the crystallographic profile was not affected by the addition of different amounts of PVP or the degree of crystallinity (which presented a value of ∼75%). The results showed that EuBDC synthesized in the absence of PVP exhibited a floral microcrystalline morphology, which changes to lamellar crystals with nanometric thickness with an increase in the PVP content. A notable result is that the surface area of the CP is approximately tripled in the presence of the stabilizer, and higher than values reported in the literature for this compound. The photoluminescence of all CPs displays a strong red emission characteristic of Eu(III) ions. Therefore, our study offers a fast, green, and economical synthetic route for the preparation of the coordination polymer EuBDC, in a controllable way with improved properties, which can promote the scale-up and broaden the applications of this material.

Polyvinylpyrrolidone-assisted novel copper antimony sulfide nanorods for highly efficient hydrogen evolution reaction

Transition metal dichalcogenides have been the most attractive material in hydrogen evolution reaction due to their advantages such as being cost-effective, earth-abundant, excellent conductivity, etc. In this study, PVP-assisted CuSbS2 nanorods were produced via hydrothermal technique. In XRD spectra, high intense peak at 28.34, 28.64, 29.54 and 29.80° clearly divulged CuSbS2 phase. The synthesized products Raman spectra also confirmed the existence of pure orthorhombic phase CuSbS2. The surface morphology of CuSbS2 has been studied by scanning electron spectroscopy, which displayed the 1D nanorod morphology and it is further confirmed by the TEM images. The elemental composition of the synthesized products is also characterized by the EDX mapping and EDX spectra, which shows the homogenous distribution of elements such as Cu, Sb and S in proper atomic percentage of 27.16, 21.06 and 51.78 respectively. Compared to the excess amount of PVP assisted CuSbS2, optimum amount of PVP assisted CuSbS2 exhibited 40.37 m2/g elevated surface area. The required over potential for 0.5 g PVP-CuSbS2 is only the 177 mV to attain 10 mA/cm2. Moreover, Tafel value of 0.5 g PVP-CuSbS2 (187 mV/dec) was smaller than pure (241 mV/dec) and 1.0 g PVP-CuSbS2 (219 mV/dec). The estimated turnover frequency (TOF) also showed that 0.5 g PVP-CuSbS2 has high intrinsic activity and exhibited excellent durability with 90.6% retention in long-term i-t test. Moreover, the catalytic activity of 0.5 g PVP-CuSbS2 was also high, which exhibited the Cdl and ECSA value of 115.3 mF/cm2 and 5.76 cm2 respectively. Therefore, the ternary metal chalcogenide revealed capable superior stability for hydrogen evolution reactions.

Hierarchical mesoporous zinc oxide microspheres for ethanol gas sensor

The increasing demand for hazardous gas detections has triggered the enormous efforts for the development of mesoporous materials for gas sensors. Especially, a universal method to synthesize such structure for semiconductor oxides is highly desirable. In this work, ZnO microspheres assembled by mesoporous nanosheets are prepared via a one-step hydrothermal method successfully. It is found that the morphology of ZnO and the thickness of ZnO mesoporous nanosheets, which affect the gas sensing response to ethanol, can be regulated by adjusting the amount of PVP. In addition, this method is also suitable for the synthesis of NiO, CuO and Co3O4 mesoporous nanosheets and the repeatability is excellent. Gas sensing investigation indicates that the gas sensors based on mesoporous ZnO nanospheres synthesized with 3.3 g PVP have the highest response (~58.4) to 100 ppm ethanol at 250°C, which is about 9.4 times higher than that of the ZnO nanosheets obtained without PVP under the same test conditions (~6.2). Furthermore, the detection limit could reach the ppb level with the response of 1.17–500 ppb ethanol. The possible mechanism of the formed structures and the enhanced ethanol sensing properties are discussed systematically.

Assessment on Performance-properties of Asymmetric Nanofiltration Membranes from Polyethersulfone/n-Methyl-2-pyrrolidone/water Blends with Poly(vinyl pyrrolidone) as Additive

In this study, the effect of poly(vinyl pyrrolidone) (PVP) additive on the fabrication of asymmetric nanofiltration (NF) membranes was investigated in terms of performance, structural details and key properties. On addition of PVP ranging from 2 to 10 wt% into the dope solution, the fabricated NF membranes exhibited significantly different in properties and improved performance. In particular, the membranes made from 2 wt% PVP had the highest water flux and salt rejection of about 3.61 × 10–6 m3/m2s and 44.49 %, respectively. Modeling results revealed that small amount of PVP (2–4 wt%) produced finer structural properties. Moreover, the key properties (rp, ∆x/Ak and ζ) of the fabricated NF membranes were found to be within the range of that of commercial NF membranes.

Preparation and characterization of SiO2@n-octadecane capsules with controllable size and structure

In this work, a series of SiO2@n-octadecane capsules were prepared by one step emulsion polymerization, the influence of emulsifying speed, ammonia and TEOS contents, reaction temperature, concentration of emulsifier and the amount of PVP on the size, structure and performance was detailed investigated. It can be seen from SEM characterization that among these factors emulsification speed had the greatest influence on capsule size, while followed by the ammonia and TEOS content. According to TEM results, the ammonia and TEOS contents were the most important factors on the structure (shell thickness and surface smoothness) of the capsules, attributing to ammonia and TEOS were the catalyst and reactant of hydrolysis polymerization, respectively. Generally, the crystallinity of the samples became worse as the size decreased. DSC results showed that excessive ammonia or TEOS caused a significant drop in the enthalpy of the samples, furthermore, the enthalpy basically decreased with the attenuation of the inner radius of the sample. The target SiO2@n-octadecane capsule was sample C2 with high enthalpy (127.7 J/g), size of 1.62 μm, shell thickness of 68 nm, and smooth surface. More importantly, within the parameters studied, a series of SiO2@n-octadecane capsules were successfully synthesized with different enthalpy values (min 85.9 J/g, max 144.3 J/g), sizes ranging from 0.63–2.75 μm, shell thickness 32–79 nm and different smooth surfaces. Therefore, the controllable synthesis of SiO2@n-octadecane capsules within the above range can be achieved by simulating different parameters and their development.

Development of SnS/PVP core/shell quantum dots with tunable color emission synthesized by microwave heating

Tin sulfide (SnS) is an earth-abundance material of non-toxic nature compared to commercially available quantum dots (QDs). Herein, a novel strategy is reported to improve the spectral tunability and stability of SnS/polyvinylpyrrolidone (PVP) core/shell QDs via microwave irradiation synthesis. Although PVP is used as a capping agent and passivating ligand for SnS QDs, as reported elsewhere, we take advantage of its polarity that allows good interaction with microwave irradiation, which impacts the nucleation and growth of SnS QDs. Furthermore, the amount of PVP in the precursor solutions controls the surface states and color purity of the QDs, and the obtained SnS/PVP QDs exhibit color-tunable emission light from blue to orange. The photoluminescence quantum yield reached the highest reported for SnS QDs, whereas 50% of their fluorescence intensity was maintained after 1-year storage at daylight. This approach provides a synthetic route to produce tunable and efficient colloidal QDs.