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In situ thermal synthesis of molybdenum oxide nanocrystals in thermoresponsive microgels
摘要： In situ formation of nanocrystals within thermoresponsive microgels has become a significant technology in the fields of catalysis and biomedicine to fabricate multifunctional hybrid nanostructures. Usually, the room temperature or cooler was set to control the formation of nanocrystals using microgels as template in such process. Here, the relatively higher temperature was used to synthesize molybdenum oxide nanocrystals where the poly (N-vinyl caprolactam) microgels were found to work as both the stabilizer and the template. Specifically, ethanol was added in the solution of the microgels to raise their volume phase transition temperature (VPTT). Later, a modified hydrothermal process was performed at 70 °C with precursor molybdic acid concentrated in the microgels matrix through the hydrogen bond between molybdic acid and N-vinyl caprolactam units. 2D nanoflakes, nanorods and nanoplatelets of molybdenum oxide were successfully synthesized. Specially, the microgels with the crosslinked degree of 2% exhibited well hybrid with controlled sizes and ideal confine of the molybdenum oxide nanoplatelets within microgels, along with strong photoluminescence intensity. These results emphasized the feasibility of poly(N-vinyl caprolactam) microgels as template and stabilizer at high temperature and provided a novel synthesis strategies for hybrid microgels applicable in wide areas of nanotechnology from catalysis, sensing to therapy.
关键词： In situ,Poly(N-vinyl caprolactam),Hybrid microgel,Molybdenum oxide,Thermoresponsive
更新于2025-09-23 15:23:52
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Using soft polymer template engineering of mesoporous TiO <sub/>2</sub> scaffolds to increase perovskite grain size and solar cell efficiency
摘要： The mesoporous (meso)-TiO2 layer is a key component of high efficiency perovskite solar cells (PSCs). Herein, pore size controllable meso-TiO2 layers are prepared using spin coating of commercial TiO2 nanoparticle (NP) paste with added soft polymer templates (SPT) followed by removal of the SPT at 500 °C. The SPTs consist of swollen crosslinked polymer colloids (microgels, MGs) or a commercial linear polymer (denoted as LIN). The MGs and LIN were comprised of the same polymer, which was poly(N-isopropylacrylamide) (PNIPAm). Large (L-MG) and small (S-MG) MG SPTs were employed to study the effect of template size. The SPT approach enabled pore size engineering in one deposition step. The SPT/TiO2 nanoparticle films had pore sizes > 100 nm; whereas, the average pore size was 37 nm for the control meso-TiO2 scaffold. The largest pore sizes were obtained using L-MG. SPT engineering increased the perovskite grain size in the same order as the SPT sizes: LIN < S-MG < L-MG and these grain sizes were larger than obtained using the control. The power conversion efficiencies (PCEs) of the SPT/TiO2-devices were ~ 20% higher than that for the control meso-TiO2 device and the PCE of the champion S-MG device was 18.8%. The PCE improvement is due to the increased grain size and more effective light harvesting of the SPT devices. The increased grain size was also responsible for the improved stability of the SPT/TiO2 devices. The SPT method used here is simple, scalable and versatile and should also apply to other PSCs.
关键词： Perovskite solar cells,template engineering,mesoporous TiO2,porosity,microgel,grain size.
更新于2025-09-23 15:21:01
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One-step scalable fluorescent microgel bioassay for the ultrasensitive detection of endogenous viral miR-US4-5p
摘要： Human cytomegalovirus (hCMV) infection is the leading cause of birth defects in newborns and death in immunosuppressed people. Traditional techniques require time-consuming and costly analyses, and sometimes result in false positive results; thus, a rapid and accurate detection for hCMV infection is necessary. Recently, hcmv-miR-US4-5p was selected as the biomarker for cytomegalovirus diagnosis and follow-up. Herein, we propose a bioassay based on microgels endowed with optical fluorescent oligonucleotide probes for the detection of circulating endogenous hcmv-microRNAs. In particular, a double strand probe, based on the fluorescence recovery after target capture, was conjugated on microgels and the probe density was opportunely optimised. Then, the microgels were directly mixed with the sample. The fluorescence read-out was measured as a function of target concentration at a fixed number of microgels per tube. As a bead-based assay, the performances of optical detection in terms of dynamic working range and limit of detection could be finely tuned by tuning the number of microgels per tube. The limit of detection of the assay could be tuned in the range from 39.1 fM to 156 aM by changing the microgel concentration from 50 μg mL?1 to 0.5 μg mL?1, respectively. The assay results specific for the selected target were stable over a one-year time span and they were not affected by the presence of human serum. Therefore, this bioassay based on microgels might represent a flexible platform that should be able to predict, identify and follow-up several diseases by monitoring freely circulating oligonucleotides in body fluids.
关键词： hcmv-miR-US4-5p,fluorescence recovery,toehold displacement,microgel bioassay,ultrasensitive detection
更新于2025-09-19 17:15:36
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Controlled synthesis of Ag-doped CuO nanoparticles as a core with poly(acrylic acid) microgel shell for efficient removal of methylene blue under visible light
摘要： Nowadays, constructing a narrow bandgap nanocomposite photocatalyst that can degrade contamination under visible light is critical but challenging. In this report, poly (acrylic acid) microgel (PAA) based nanocomposites (Ag@CuO/PAA NC) were constructed via free radical solution polymerization by varying the concentration of silver-doped copper oxide nanoparticles (Ag@CuO NPs) from 0 to 12%. As prepared Ag@CuO and Ag@CuO/PAA were characterized by X‐ray diffraction spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray and X-ray photoelectron spectroscopy. The size of Ag@CuO NPs was found to be 30–50?nm. The photocatalytic activity of CuO is increased by Ag doping and C3 NPs show the best photodegradation of methylene blue (MB). Then, 4% of Ag@CuO nanoparticles were incorporated into PAA microgel, the resultant nanocomposite showed a drastic increase in photodegradation of MB. Ag@CuO/PAA NC completely degraded dye in only 30?min which was degraded up to 65% in 60?min. by Ag@CuO NPs. The successful combination of PAA with Ag@CuO boosts the photocatalytic activity because microgel provides a large surface to adsorb pollutants. Ag@CuO/PAA NC reused successfully for photodegradation of dye due to the recycling ability of microgels. This study gives a good insight into planning a significant visible‐light‐driven photocatalyst for environmental remediation.
关键词： photocatalytic degradation,methylene blue,Ag-doped CuO nanoparticles,visible light,poly(acrylic acid) microgel
更新于2025-09-19 17:13:59
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Modulating Crystallization in Semitransparent Perovskite Films Using Submicrometer Spongelike Polymer Colloid Particles to Improve Solar Cell Performance
摘要： Semitransparent perovskite solar cells (PSCs) have excellent potential for solar window applications. A major challenge exists, however, in achieving uniform coverage for thin perovskite films. Unfortunately, uncontrolled pinhole formation is a common problem for such films that obstructs development, especially for large area devices. In this study, we used very small (submicrometer) swellable polymer colloid particles (microgels) as additives to prepare uniform thin CH3NH3PbI3 (MAPI) perovskite films. Microgels (MGs) are good film-formers and promoted formation of semitransparent (ST) perovskite films with improved coverage. The MGs act as colloidal sponges and delayed release of perovskite precursors, thereby delaying perovskite crystallization. The ST films prepared using MGs had fewer pinholes compared to the MG-free control films. X-ray photoelectron spectroscopy showed evidence of Pb coordination by the MGs and they were shown to passivate MAPI. Remarkably, the submicrometer MGs used in this study decreased light scattering for the ST films. Planar devices constructed using a 10 nm ST film with an average visible transmittance of 46.8% gave an average power conversion efficiency (PCE) of 7.69%, which compares favorably to literature values. The average PCE increased to 9.62% upon inclusion of a thin meso-TiO2 layer. These PCE values are significantly higher than that achieved for the MG-free ST control (4.93%). The MGs and approaches used here are scalable and should apply to other ST perovskite films, solar cells, and, potentially, tandem devices.
关键词： Perovskite solar cell,semitransparent,crystallization,average visible transmittance,microgel
更新于2025-09-11 14:15:04
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Synthesis, Characterisation and Applications of Polymer–Silica Core–Shell Microparticle Capsules
摘要： Encapsulation is a powerful method for the targeted delivery of concentrated reagents, as well as capture of valuable materials in dilute systems. To this end, many encapsulation schemes for specific scenarios have been devised, that incorporate chemospecificity or stimulus response in terms of uptake or release. However, an encapsulation platform that enables highly tailorable surface chemistry for targeting, stimulus response, and core chemistry for capture and release of reagents remains elusive. Here we present such a system comprising composite core–shell capsule particles of hydrophilic polymers coated with thin silica layers, synthesised via straightforward one-pot syntheses. Silica is found to encapsulate a range of polymer hydrogels through a mechanism independent of the specific core chemistry. The hybrid materials possess significantly enhanced rigidity, while allowing surface modification through simple yet versatile silane coupling reactions without a reduction in the functionality of the core. They are shown to have applications as diverse as recyclable catalysis and controlled delivery vehicles for agrochemicals. The successful synthesis and utilisation of this catalogue of materials indicates the broader capability of simple composite structures in an array of high value applications.
关键词： catalysis,silica,microgel,encapsulation,Hybrid materials
更新于2025-09-10 09:29:36