Monodisperse Silica Nanoparticles Research Articles

Protocrystallinity of Monodispersed Ultra-Small Templated Mesoporous Silica Nanoparticles.

Monodisperse and semi-faceted ultra-small templated mesoporous silica nanoparticles (US-MSNs) of 20-25 nm were synthesized using short-time hydrolysis of tetraethoxysilane (TEOS) at room temperature, followed by a dilution for nucleation quenching. According to dynamic light scattering (DLS), a two-step pH adjustment was necessary for growth termination and colloidal stabilization. The pore size was controlled by cetyltrimethylammonium bromide (CTAB), and a tiny amount of neutral surfactant F127 was added to minimize the coalescence between US-MSNs and to favor the transition towards internal ordering. Flocculation eventually occurred, allowing us to harvest a powder by centrifugation (~60% silica yield after one month). Scanning transmission electron microscopy (STEM) and 3D high-resolution transmission electron microscopy (3D HR-TEM) images revealed that the US-MSNs are partially ordered. The 2D FT transform images provide evidence for the coexistence of four-, five-, and sixfold patterns characterizing an "on-the-edge" crystallization step between amorphous raspberry and hexagonal pore array morphologies, typical of a protocrystalline state. Calcination preserved this state and yielded a powder characterized by packing, developing a hierarchical porosity centered at 3.9 ± 0.2 (internal pores) and 68 ± 7 nm (packing voids) of high potential for support for separation and catalysis.

Silica Nanoparticles Functionalized with an Ionic Liquid: A Green and Efficient Heterogeneous Catalyst for a Cascade Reaction

AbstractA new strategy for a catalytic C−C bond forming cascade reaction comprising acetal hydrolysis and Knoevenagel condensation is presented here. The heterogeneous nanocatalyst is prepared by immobilizing an ionic liquid on the surface of highly monodisperse silica nanoparticles. This work is the first example of showing that there is no need to use bifunctional acid‐base catalysts for a cascade reaction including the hydrolysis of benzaldehyde dimethyl acetal to benzaldehyde and the subsequent Knoevenagel condensation of the resulting benzaldehyde with malononitrile. It is shown here that these reactions can proceed smoothly with a mono‐functional heterogeneous catalyst that contains a neutral ionic liquid. It has been proposed that such a neutral ionic liquid can “switch on” to an acidic catalyst in conjunction with water. The selected ionic liquid has potentially biodegradability characteristics, which is an important issue to achieve a sustainable catalyst. The simple procedure for preparing both the ionic liquid and the monodisperse silica nanoparticles provides opportunities for a large‐scale synthesis of the catalyst. This work introduces a breakthrough in the design and synthesis of heterogeneous catalysts for acid/base catalyzed cascade organic reactions.

An Unprecedented Metal Distribution in Silica Nanoparticles Determined by Single-Particle Inductively Coupled Plasma Mass Spectrometry.

Metal-containing nanoparticles are now common in applications ranging from catalysts to biomarkers. However, little research has focused on per-particle metal content in multicomponent nanoparticles. In this work, we used single-particle inductively coupled plasma mass spectrometry (ICP-MS) to determine the per-particle metal content of silica nanoparticles doped with tris(2,2'-bipyridyl)ruthenium(II). Monodispersed silica nanoparticles with varied Ru doping levels were prepared using a water-in-oil microemulsion method. These nanoparticles were characterized using common bulk-sample methods such as absorbance spectroscopy and conventional ICP-MS, and also with single-particle ICP-MS. The results showed that averaged concentrations of metal dopant measured per-particle by single-particle ICP-MS were consistent with the bulk-sample methods over a wide range of dopant levels. However, the per-particle amount of metal varied greatly and did not adhere to the usual Gaussian distribution encountered with one-component nanoparticles, such as gold or silver. Instead, the amount of metal dopant per silica particle showed an unexpected geometric distribution regardless of the prepared doping levels. The results indicate that an unusual metal dispersal mechanism is taking place during the microemulsion synthesis, and they challenge a common assumption that doped silica nanoparticles have the same metal content as the average measured by bulk-sample methods.

Facile synthesis of monodispersed mesoporous silica nanoparticles with ultra-large mesopores through a NaBH4-assisted hydrothermal process

This work reports the facile synthesis of monodispersed ultra-large mesopore mesoporous silica nanoparticles (ULP-MSNs) through a new and simple NaBH4-assisted hydrothermal process (NAH process). Such preparation of ULP-MSNs enables the small mesopore size (<3 nm) of as-prepared conventional MSNs to be effectively enlarged to over 20 nm. The synthetic parameters were systematically studied, and it was shown that the initial ethanol added in the synthesis mixture (1st ethanol), NaBH4, HCl(a.q.) and the ethanol added in the mixture (2nd ethanol) during the hydrothermal (HT) process and HT conditions play synergistic roles in enlarging mesopores by NAH process. We also revealed the mesopore-enlargement mechanism. By this method, the resultant ULP-MSNs possess tunable ultra-large mesopore sizes (18–31 nm), monodispersed spherical morphology, and controllable particle sizes (105–268 nm). The method presented here could effectively enlarge and adjust the mesopores of the MSNs. We supposed our approach may provide a platform of nanotechnology for the preparation of porous silica materials with adjustable mesopore sizes, which will be promising for practical applications.

Biomimetic mineralization of positively charged silica nanoparticles templated by thermoresponsive protein micelles: applications to electrostatic assembly of hierarchical and composite superstructures

Exploiting the ability of a solid-binding elastin-like peptide to micellize, we mineralize monodisperse silica nanoparticles whose positive surface charge enables one-step electrostatic assembly of various mono- and bi-material superstructures.

Facile and controllable preparation of mesoporous silica nanoparticles with ultra-large mesopores enabled by an ammonium chloride–assisted hydrothermal process

This work reports the facile preparation of monodispersed ultra-large mesopore mesoporous silica nanoparticles (ULP-MSNs) with controllable mesopore sizes and particle sizes. The key design to such preparation lies in the application of ammonium chloride (NH4Cl) assisted-hydrothermal (AAH) process to as-prepared conventional MSNs, whose small mesopore sizes of about 2 nm can be effectively enlarged to over 16 nm. Based on the systematic study of the synthetic parameters, it was recognized that the initial ethanol added in the synthesis mixture (1st ethanol), NH4Cl, and the ethanol added in the mixture (2nd ethanol) during the hydrothermal (HT) process and HT conditions play synergistic roles in enlarging mesopores by AAH process. The mechanism of mesopore enlargement was also studied. By this method, ULP-MSNs with variable mesopore sizes in a range of 14 nm–26 nm, large synthesis domain, and controllable particle sizes ranging from 106 nm to 267 nm can be produced in a facile manner. This work, we believe, represents a new strategy for the preparation of ULP-MSNs and will promote their various applications.

Hollow-polydopamine-nanocarrier-based near-infrared-light/pH-responsive drug delivery system for diffuse alveolar hemorrhage treatment.

Introduction: Diffuse alveolar hemorrhage (DAH) is a serious complication caused by systemic lupus erythematosus (SLE). Tissue damage and changes in immune response are all associated with excessive free radical production. Therefore, removing excess reactive oxygen species are considered a feasible scheme for diffuse alveolar hemorrhage treatment. Cyclophosphamide is often used as the main therapeutic drug in clinics. However, CTX carries a high risk of dose-increasing toxicity, treatment intolerance, and high recurrence rate. The combination of therapeutic drugs and functional nanocarriers may provide an effective solution. PDA is rich in phenolic groups, which can remove the reactive oxygen species generated in inflammatory reactions, and can serve as excellent free radical scavengers. Methods: We developed a hollow polydopamine (HPDA) nanocarrier loaded with CTX by ionization to prepare the novel nanoplatform, CTX@HPDA, for DAH treatment. The monodisperse silica nanoparticles were acquired by reference to the typical Stober method. PDA was coated on the surface of SiO2 by oxidation self-polymerization method to obtain SiO2@PDA NPs. Then, HPDA NPs were obtained by HF etching. Then HPDA was loaded with CTX by ionization to prepare CTX@HPDA. Then we tested the photothermal effect, animal model therapeutics effect, and biosafety of CTX@HPDA. Results: Material tests showed that the CTX@ HPDA nanoplatform had a uniform diameter and could release CTX in acidic environments. The vitro experiments demonstrated that CTX@HPDA has good photothermal conversion ability and photothermal stability. Animal experiments demonstrated that the CTX@HPDA nanoplatform had good biocompatibility. The nanoplatform can dissociate in acidic SLE environment and trigger CTX release through photothermal conversion. Combining HPDA, which scavenges oxygen free radicals, and CTX, which has immunosuppressive effect, can treat pulmonary hemorrhage in SLE. Micro-CT can be used to continuously analyze DAH severity and lung changes in mice after treatment. The pulmonary exudation in the various treatment groups improved to varying degrees. Discussion: In this study, we report a photothermal/PH-triggered nanocarrier (CTX@HPDA) for the precise treatment of SLE-DAH. CTX@HPDA is a simple and efficient nanocarrier system for DAH therapy. This work provides valuable insights into SLE treatment.

Synthesis of Monodispersed Hollow Mesoporous Organosilica and Silica Nanoparticles with Controllable Shell Thickness Using Soft and Hard Templates

Hollow mesoporous nanoparticles with controllable size (less than 100 nm) are desired as drug-delivery carriers. Herein, we report the synthesis of monodispersed hollow mesoporous organosilica (HMOS) and hollow mesoporous silica (HMS) nanoparticles using soft and hard templating methods. HMOS shells, with 1,2-bis(triethoxysilyl)ethane (BTEE) as the precursor and hexadecyltrimethylammonium bromide and sodium dodecyl sulfate (SDS) as the soft templates, were formed on monodispersed silica nanoparticles (SNPs), which were used as the hard templates. HMOS and HMS nanoparticles were obtained by removing the SNPs after three rounds of ammonia dialysis. The hollow size of HMOS can be tuned by changing the size of the SNPs. By using SNPs with a size of 36.5 nm, hollow spaces of approximately 20 nm connected the surface through narrow pores (<5 nm). Mesopores of approximately 12 nm were formed by the surfactant micelles. Additionally, the interparticle space in HMOS and HMS was approximately 12 nm. The shell thicknesses of HMOS and HMS could be tuned in the range of 5-9 nm by changing the BTEE amount. Moreover, the amount of surfactant used varied the porous structure. The HMOS with a thickness of 5 nm exhibited a Brunauer-Emmett-Teller (BET) surface area of 268 m2/g and a total pore volume of 1.14 cm3/g. Meanwhile, HMS demonstrated a BET surface area of 553 m2/g and a total pore volume of 1.82 cm3/g while maintaining a hollow structure. HMOS displayed a high loading capacity for ibuprofen (3009 mg/g), and its drug release system showed a sustained-release property. Therefore, the HMOS preparation using hard and soft templates proposed herein can control the hollow size and shell thickness for drug-delivery applications.

Novel shear thickening fluids possessing high shear rates using monodispersed silica nanoparticles and PEG

Novel shear thickening fluids possessing high shear rates using monodispersed silica nanoparticles and PEG

Precise dapagliflozin delivery by cardiac homing peptide functionalized mesoporous silica nanocarries for heart failure repair after myocardial infarction.

Myocardial infarction (MI) may cause irreversible damage or destroy to part of the heart muscle, affecting the heart's ability and power to pump blood as efficiently as before, often resulting in heart failure (HF). Cardiomyocyte death and scar formation after MI may then trigger chronic neurohormonal activation and ventricular remodeling. We developed a biocompatible and mono-dispersed mesoporous silica nanoparticles (MSN) divergent porous channel for dapagliflozin (DAPA) loading. After surface modification of the cardiac-targeting peptides, the novel drug delivery system was successfully homed, and precisely released drugs for the hypoxic and weak acid damaged cardiomyocytes. Our biocompatible MSN- based nanocarriers for dapagliflozin delivery system could effective cardiac repair and regeneration in vivo, opening new opportunities for healing patients with ischemic heart disease in clinical.

Polyamidoamine dendrimer-functionalized silica nanocomposite with polydopamine coating for dispersive micro solid-phase extraction of benzoylurea insecticides in water samples

近年来,由农药残留导致的环境污染问题已引起社会的广泛关注,开发便捷高效的分析方法对农药残留进行检测和监测十分必要。研究设计并成功制备了聚多巴胺涂敷的聚酰胺-胺树状分子功能化的二氧化硅复合材料(SiO2-PAMAM-PDA),并采用透射电镜对其进行表征。开发了以此复合材料为吸附剂的分散微固相萃取方法(D-μ-SPE),并结合高效液相色谱对水基质中的4种苯甲酰脲类杀虫剂(BUs)残留进行了富集检测。多巴胺结构中含有丰富的苯环、氨基及羟基,可与目标物形成氢键、π-π相互作用,从而增强了材料对苯甲酰脲的萃取能力。对吸附剂用量、萃取时间等可能影响萃取效率的条件进行了单因素优化。在最优条件下,该方法的线性范围在10~500 μg/L之间,根据3倍信噪比(S/N)计算所得的检出限(LOD)为1.1~2.1 μg/L,回收率为82.8%~94.1%,相对标准偏差(RSD)为2.1%~8.0%。将建立的方法与已报道的以苯甲酰脲作为目标物的方法进行了对比,发现方法样品用量及萃取剂用量均较少,且所需前处理时间较短,有机溶剂消耗也较少,为苯甲酰脲类农药的检测提供了更快速、绿色的选择。为评估所开发方法的实际样品适用性,将其应用于3种河水样品中4种苯甲酰脲类杀虫剂的分析检测,所得回收率及RSD分别为69.5%~99.4%和0.2%~9.5%,表明此方法在实际样品中同样具有较高的准确性和精密度。

Cascade Resonance Energy Transfer for the Construction of Nanoparticles with Multicolor Long Afterglow in Aqueous Solutions for Information Encryption and Bioimaging

AbstractThere are still huge challenges in the development of carbon dots (CDs) based long afterglow materials with multicolor emissions, especially in aqueous solutions. This work reports a novel strategy of achieving of multicolor long afterglow in aqueous solution by incorporating phosphorescent CDs and fluorescent dyes into sub‐20 nm monodispersed silica nanoparticles. The silica matrix not only stabilizes the triplet excitons of CDs but also facilitates the efficient cascade Förster resonance energy transfer between the phosphorescent donor (CDs) and the energy acceptor (fluorescent dyes), which enables intensive multicolor long afterglow with adjustable wavelength from 510 to 610 nm and the largest Stokes shift of 255 nm. Based on these multicolor long afterglow nanoparticles, some time‐resolved, color multiple information encryptions are designed. By eliminating background noise, the signal‐to‐noise ratio of in vivo afterglow imaging is as high as 155.1 in the in vivo imaging system. Interestingly, the afterglow signal in mice can be easily and conveniently collected by the camera of cell phones, which may make in vivo bioimaging portable and inexpensive. This study will provide new ideas for the synthesis of multicolor CDs‐based long afterglow materials in solutions.

Synthesis of antibiotic-modified silica nanoparticles and their use as a controlled drug release system with antibacterial properties

In this study, monodispersed silica nanoparticles were synthesized using the Stöber method. The synthesized nanoparticles underwent a range of surface modifications and were converted to nanoparticles with drug release and antibacterial features. For modification, firstly –NH2 groups were created on the silica nanoparticle surface using (3-Aminopropyl)triethoxysilane (APTES). In the second stage, hexachlorocyclotriphosphazene (Phz) molecules were bound to the silica nanoparticle surfaces due to these amino groups. In the final stage of modification, the chloride groups in the hexachlorocyclotriphosphazene structure were modified with trimethoprim (TMP) and nanoparticles with antibacterial properties were obtained. The modified silica nanoparticles were characterized with scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), Transmission Electron Microscopy (TEM), and Thermogravimetric analysis (TGA). The silica-based nanoparticles were used for release of rhodamine 6G, chosen as a model drug. As a result of the drug release studies, the modified silica nanoparticles were found to abide by the Korsmeyer–Peppas low power model and non-Fickian release mechanism as release model. Additionally, nanoparticles both loaded and not loaded with the model drug were determined to have antibacterial properties against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus bacteria.

Temperature-responsive P(NIPAM-co-NHMA)-grafted organic-inorganic hybrid hollow mesoporous silica nanoparticles for controlled drug delivery

Hollow mesoporous silica nanoparticles (HMSN) have been widely studied as drug delivery carriers due to their high drug loading capacity in the internal cavity. In this study, monodisperse and temperature-responsive hollow mesoporous silica nanoparticles (HMSN@P(NIPAM-co-NHMA)) were synthesized and investigated. HMSN and HMSN@P(NIPAM-co-NHMA) were characterized by SEM, TEM, FT-IR, TGA, XRD and nitrogen adsorption-desorption isotherms. The results showed that the cross-linked temperature-sensitive polymer P(NIPAM-co-NHMA) was grafted onto the surface of HMSN. Subsequently, using puerarin (PUE) as the drug model, the results demonstrated that the HMSN@P(NIPAM-co-NHMA) had an excellent loading efficiency and exhibited excellently temperature-sensitive release behavior. Furthermore, the biocompatibility and stability of HMSN and HMSN@P(NIPAM-co-NHMA) were studied by MTT assay and hemolysis assay, the results indicated HMSN@P(NIPAM-co-NHMA) possessed excellent biocompatibility and stability. Thus, we have successfully synthesized HMSN@P(NIPAM-co-NHMA), and the drug release is temperature-responsive, which can realize controlled drug release.

Nonlinear charge regulation for the deposition of silica nanoparticles on polystyrene spherical surfaces

HypothesisWe describe the deposition behavior of monodispersed silica nanoparticles on polystyrene spherical particles by using modified pairwise DLVO (Derjaguin-Landau-Verwey-Overbeek) interaction force profiles at pH values between two and twelve. Our modified model contains a new nonlinear charge regulation parameter that considers redistribution of ions, which allows us to realistically express the electrical double layer (EDL) interaction forces. ExperimentsSilanol-terminated silica nanoparticles (7.6 ± 0.4 nm), l-lysine-covered silica nanoparticles (7.8 ± 0.4 nm), and polyallylamine hydrochloride-covered polystyrene (PAH/PS) particles (348 ± 1 nm) were synthesized. Then, each type of silica nanoparticle was deposited on the PAH/PS particles at a range of pH values. FindingsOur new regulation parameter describes the realistic redistribution of charges governed by pH, total salt concentration, ionic strength of solution, and separation distance of particles. We find that this regulation parameter can be roughly approximated from the absolute values of theoretically calculated surface charge density and potential distributions, as well as experimentally measured ζ-potentials. Morphological analysis using electron microscopy of the experimental systems shows that the modified pairwise DLVO interaction forces exceptionally describe the deposition behavior of the silica nanoparticles physically adsorbed on the PAH/PS particle substrates.

Hydrolysis and Condensation of Tetraethyl Orthosilicate at the Air–Aqueous Interface: Implications for Silica Nanoparticle Formation

The silica (SiO2) nanoparticles of a well-known silica precursor tetraethyl orthosilicate (TEOS) are generally synthesized via a promising solution-gelation inorganic polymerization process. The monodisperse silica nanoparticles have potential applications ranging from the formation of dental nanocomposites to antireflective coatings. In the present study, we have systematically investigated the in situ interfacial molecular structure of TEOS and its impact on the interfacial water structure during the processes of hydrolysis and condensation at the air–aqueous interface using sum-frequency generation (SFG) vibrational spectroscopy. With the presence of water, a gradual decrease in the SFG intensity in the CH-stretch region for each concentration of TEOS with time reflects the elimination of ethoxy groups, which is a signature of the hydrolysis process. Further, the impact of the hydrolysis process is revealed from the significant enhancement in the SFG signal in the OH-stretch region. The hydrolysis of TEOS is then followed by condensation in which the ≡Si─O– charged species are replaced by forming the ≡Si─O─Si≡ bridging network. The signature of the condensation process is reflected with the gradual decrease in the observed enhanced SFG signal in the OH-stretch region. The formation of monodispersed silica nanoparticles as an end product of size variation from 1.75 to 4.67 nm with the increase in TEOS concentration is confirmed with the DLS measurements. We have also probed the pH-dependent SFG studies at three different pH values (2.0, 5.8, and 9.0). The dominant pH-dependent hydrolysis process is revealed from the observed molecular structure of TEOS at the air–aqueous interface.

Layer-by-layer assembly of nanofilms from colloidally stable amine-functionalized silica nanoparticles

The assembly of uniform thin films with functional silica nanoparticles (FSNPs) by the layer-by-layer (LbL) technique has been studied to provide rough, robust, and functional surfaces. Initially, monodisperse silica nanoparticles (SNPs) have been synthesized by the reverse microemulsion method. Then SNPs have been functionalized using amino silane coupling agents with various chain lengths and amine positions such as (3-aminopropyl)trimethoxy silane (APS), N-[3-(trimethoxysilyl)propyl]-N,N,N-trimethylammonium chloride (NPC), N -(6-aminohexyl)aminopropyltrimethoxy silane (AHAPS), and 3-aminopropyl(dimethyl)ethoxy silane (APDMES). The amine-functionalized silica nanoparticles have been characterized using zeta potential, Fourier Transform-Infrared Spectroscopy (FT-IR), and 1 H Nuclear Magnetic Resonance (NMR) spectroscopy to prove the existence of amine groups on the silica surface. Scanning electron microscopy (SEM) images have revealed that the LbL assembled thin film coatings of FSNPs are uniform and monodisperse. The thickness measurements of the coatings have been conducted by spectroscopic ellipsometry. Water contact angle measurements were performed to analyze the alteration of surface features with functional groups. The roughness, topography, and elastic modulus of the assembled thin-film coatings were probed by atomic force microscopy (AFM). The dispersion of AHAPS-FSNPs has indicated superior colloidal stability than other FSNPs because of their secondary amines creating steric hindrance. Moreover, AHAPS-FSNPs film exhibited the lowest coating thickness and the highest elastic modulus comparing with the other FSNPS because of their crosslinking and hydrogen-bonding ability. Briefly, in this work, LbL assembly of the amine FSNPs was established by an extensive investigation to form rough and functional surfaces for many demanding applications.

Monodispersed large-mesopore mesoporous silica nanoparticles enabled by sulfuric acid assisted hydrothermal process

Abstract In this work, it is demonstrated that monodispersed large-pore mesoporous silica nanoparticles (ML-MSNs) can be prepared by a sulfuric acid assisted hydrothermal process (SAH). The strategy is based on a SAH process enabled transformation from conventionally prepared MSNs with small mesopores (~2.6 nm) into large-mesopore ML-MSNs (over 10 nm) and high surface area (exceeding 500 m2g-1) in a rather green and controllable manner. A synergistic effect of ethanol employed in the synthesis step and more importantly the hydrothermal treatment process step in ethanolic sulfuric acid solution at high temperature is newly acknowledged in such SAH process, as manifested by different techniques. Such process enables reliable control over porous structures by varying the SAH condition. Moreover, ML-MSNs with tuneable mesostructures are shown to allow rational control over loading and release performance of water-insoluble drug molecules of Indomethacin.

Investigating the effect of nonionic surfactant on the silica nanoparticles formation and morphology in a microfluidic reactor

The conventional sol-gel method used to synthesize monodispersed spherical silica nanoparticles produces particles with irregular shapes and low monodispersity. Microreactors show a promising new platform to synthesize nanomaterials due to their unique flow and mixing characteristics. In most known shear-based droplet generation microreactors, the effect of the flowing liquid’s physical properties on the reactor performance and product characteristics are not well investigated. Scaling-down the flow system was proven to change the flow behavior which will be dominated by the liquid apparent physical properties that are highly controllable. A new method to synthesize silica nanoparticles adapting the sol-gel approach in a microfluidic chip is proposed and experimentally tested in the present work. This work also analyzes changing the flowing reactants’ physical properties using nonionic surfactants with different concentrations on the reaction performance and nanoparticle size and properties. A custom-made microreactor, made from polydimethylsiloxane, was designed and then fabricated using a direct writing technique. The investigated surfactant concentration was within the range of 1 to 5 vol/vol%, respective to tetraethyl orthosilicate. A traditional bench-scale sole-gel method was also performed with the same reaction properties for comparison purposes. The obtained nanoparticles were characterized using transmission electron microscopy and EDX. The silica nanoparticles synthesized from a bench-scale system showed poor monodispersity and an irregular shape compared to the perfect spherical particles produced from the microflow system. The addition of surfactant reduced the coalescence of the droplet besides reducing the size of the droplets. Increasing the surfactant concentration reduces the silica nanoparticle size. The results showed that highly monodispersed silica nanoparticles with an average size of 5.76 ± 1.27 nm were synthesized using the microflow system comparing to silica nanoparticles with a mean size of 95 ± 4 nm produced from the bench-scale.

Synthesis of size-controlled and highly monodispersed silica nanoparticles using a short alkyl-chain fluorinated surfactant.

Highly monodispersed silica nanoparticles (SiNPs) were synthesised using a fluorinated surfactant, HOCH2CH(CF3)CO2H, and its efficiency was compared with efficiencies of five other surfactants. The size of the SiNPs (∼50–200 nm) was controlled by controlling the surfactant amount. The short alkyl-chain fluoro surfactant was found to be more efficient at producing monodispersed SiNPs than its long alkyl-chain fluoro or non-fluorinated surfactant counterparts.