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This review focuses on the recent advances in the lesser-studied microemulsion synthesis methodologies of the following noble metal colloid systems (i.e., Os, Re, Ir, and Rh) using either a normal or reverse micelle templating system. The aim is to demonstrate the utility and potential of using this microemulsion‐based approach to synthesize these...
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... characteristic of surfactants is their tendency to aggregate and form micelles after a particular concentration, the critical micelle concentration (CMC) [22,24,31]. In an O/W microemulsion, the hydrophilic head groups of a surfactant molecule are oriented out from the micelle (in order for it to be in contact with water with which it has molecular affinity) and the hydrophobic tails associate within the core (within the entrapped oil droplets), so 'normal micelles' form and vice versa for a W/O microemulsion, where 'reverse micelles' are generated ( Figure 2) [21,22]. The core of reverse microemulsions (reverse micelles) can play a significant and active role for NPs synthesis as 'nano reactors' [21,22]. ...
Context 2
... characteristic of surfactants is their tendency to aggregate and form micelles after a particular concentration, the critical micelle concentration (CMC) [22,24,31]. In an O/W microemulsion, the hydrophilic head groups of a surfactant molecule are oriented out from the micelle (in order for it to be in contact with water with which it has molecular affinity) and the hydrophobic tails associate within the core (within the entrapped oil droplets), so 'normal micelles' form and vice versa for a W/O microemulsion, where 'reverse micelles' are generated ( Figure 2) [21,22]. The core of reverse microemulsions (reverse micelles) can play a significant and active role for NPs synthesis as 'nano reactors' [21,22]. ...
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Metal Nanoparticles show specific physical and chemical properties attributed to its small size and high surface area to volume ratio. These chemical and physical properties using different strategies and conditions enhance its biological application especially in the field of medicine. Earth abundant and cheap cupper metal is the essential element...
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... Hydrolysis of K 2 ReCl 6 in water as proposed by Pavlova et al. [21] The rarity and the cost of rhenium have limited the number of previous efforts to study its nano structure synthesis methods [16], so classifying it as the second least-studied precious nano metal, based on the number of references returned on a web of science database search [22,23]. This number furthermore drops significantly when paper searches are limited to the ME-template techniques (which were reviewed in a previous article [24] in 2019). Updated research revealed only two new studies [25,26], resulting in a total of fewer than 10 articles. ...
... Understanding the dynamics of dispersion stability is essential for developing strategies to improve and manipulate the dispersion of CNTs. Dispersion stability is not only important for preserving the intrinsic properties of CNTs, but also for enabling their applications in various energy devices, such as solar cells, fuel cells, batteries, supercapacitors, and thermoelectrics [6,12,17,18,[20][21][22]25,26]. ...
... Non-covalent functionalization can be achieved through various methods, such as surfactant wrapping, polymer wrapping, DNA wrapping, and biomolecule adsorption [17,18]. Surfactant wrapping is one of the most common methods for non-covalent functionalization, which involves coating CNTs with surfactant molecules, such as sodium dodecyl sulfate (SDS) or Triton X-100 ( Figure 3) [17,25]. These molecules can form micelle-like structures around the CNTs, stabilizing them in water or other polar solvents. ...
... Polymer wrapping is another method for non-covalent functionalization, which involves wrapping CNTs with polymer chains, such as polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG). These polymers can form a thin layer around the CNTs, preventing their aggregation and enhancing their biocompatibility [12,17,18,25]. ...
Carbon nanotubes (CNTs), with their extraordinary combination of mechanical, electrical, and thermal properties, have emerged as a revolutionary class of nanomaterials with immense potential in energy storage and harvesting devices. Realizing this potential hinges on a fundamental challenge: the dispersion stability of CNTs within various matrices. This review paper provides a comprehensive exploration of the critical interplay between CNT dispersion stability and its far-reaching implications for the performance of energy storage and harvesting technologies. By delving into the underlying mechanisms of dispersion, the strategies to achieve stability, and the direct effects on device functionality, this review sheds light on the intricate relationship between nanotube dispersion and the advancement of energy-related applications.
... Reverse micelle is a chemical method utilized for making nanomaterials of desired size and shape (Shiri et al., 2019). An emulsion of oil-in-water type forms micelles where hydrophobic tails are projected towards the core that has confined oil droplets inside it. ...
Microfluidic systems are promising alternatives for continuous synthesis of nanoparticles in controlled environments, overcoming challenges of conventional methods. Stable nanoparticles within a narrow range of size and shape distribution can be reliably produced by controlling geometrical configuration of microfluidic devices and optimizing various operational parameters. This chapter provides an overview of fundamentals and advances in microfluidic synthesis of nanoparticles, categorizing devices into continuous and segmented flow microfluidic platforms. Strategies for functionalization of nanoparticles are explained, and their diverse applications in various fields are elaborated. Future prospects and underlying challenges are also examined for the commercialization of microfluidic devices for nanoparticle synthesis.
... Microemulsion is an important technique used for the synthesis of MNPs because of its valuable features such as decreased size of the droplet, spherical structure, high stability and its tunable tendencies for size-controlled synthesis of MNPs [40]. This method involves the mixing of two immiscible solvents; water and oil that are thermodynamically stable with or without an active agent (surfactant) [32,41]. ...
Magnetic nanoparticles (MNPs) have gained significant attention among several nanoscale materials during the last decade due to their unique properties. These properties make them successful nanofillers for drug delivery and a number of new biomedical applications. MNPs are more useful when combined with biodegradable polymers. In this review, we discussed the synthesis of polycaprolactones (PCL) and the various methods of synthesizing magnetic iron oxide nanoparticles. Then, the synthesis of composites that is made of PCL and magnetic materials (with special focus on iron oxide nanoparticles) were highlighted. In addition, we comprehensively reviewed their application in drug delivery, cancer treatment, wound healing, hyperthermia, and bone tissue engineering. Other biomedical applications of the magnetic PCL such as mitochondria targeting are highlighted. Moreover, biomedical applications of magnetic nanoparticles incorporated into other synthetic polymers apart from PCL are also discussed. Thus, great progress and better outcome with functionalized MNPs enhanced with polycaprolactone has been recorded with the biomedical applications of drug delivery and recovery of bone tissues.
... Surfactant-stabilized microemulsions [16] can form reverse micelles as a confined reaction space for co-precipitation to limit the particle growth. Such microemulsions have been used as a reaction medium for, for example, metal nanoparticles, [17] metal salt aggregates, [18] core shell nanoparticles, [19] polymers, [20] hydroxides, [21] and oxides, [22] including LDHs. [23] While confinement of particle growth has been accomplished in these works, exact control to tune particle and pore size by specific synthesis parameters is often lacking, but highly desirable for the investigation of mesostructure-reactivity relationships and confinement effects. ...
Cobalt iron containing layered double hydroxides (LDHs) and spinels are promising catalysts for the electrochemical oxygen evolution reaction (OER). Towards development of better performing catalysts, the precise tuning of mesostructural features such as pore size is desirable, but often hard to achieve. Herein, a computer‐controlled microemulsion‐assisted co‐precipitation (MACP) method at constant pH is established and compared to conventional co‐precipitation. With MACP, the particle growth is limited and through variation of the constant pH during synthesis the pore size of the as‐prepared catalysts is controlled, generating materials for the systematic investigation of confinement effects during OER. At a threshold pore size, overpotential increased significantly. Electrochemical impedance spectroscopy (EIS) indicated a change in OER mechanism, involving the oxygen release step. It is assumed that in smaller pores the critical radius for gas bubble formation is not met and therefore a smaller charge‐transfer resistance is observed for medium frequencies.
... The case is opposite for oil-inwater microemulsion. In the synthesis of SPIONs, two microemulsions consisting of a metal salt and a reducing agent are mixed together, resulting in an exchange of reactants between micelles [70]. ...
... Reproduced with permission [47] (John Wiley and Sons, 2018). Different types of surfactants, such as anionic, cationic, or non-ionic surfactants, have been used to improve the dispersibility of CNTs (Figure 3) [48]. In general, the dispersibility of CNTs in an aqueous solution depends significantly on the type of surfactants. ...
... The findings can provide a basis for research on enhancing the dispersibility of CNTs using surfactants. [48]. Reproduced with permission [48] (MDPI, 2019). ...
... [48]. Reproduced with permission [48] (MDPI, 2019). ...
In the battery field, carbon nanotubes (CNTs) attract much attention due to their potential as a supporting conducting material for anodes or cathodes. The performance of cathodes or anodes can be optimized by introducing densely packed CNTs, which can be achieved with high dispersibility. The efficiency of CNT usage can be maximized by enhancing their dispersibility. An effective technique to this end is to incorporate surfactants on the surface of CNTs. The surfactant produces a surface charge that can increase the zeta potential of CNTs, thereby preventing their agglomeration. Additionally, surfactants having long chains of tail groups can increase the steric hindrance, which also enhances the dispersibility. Notably, the dispersibility of CNTs depends on the type of surfactant. Therefore, the results of dispersibility studies of CNTs involving different surfactants must be comprehensively reviewed to enhance the understanding of the effects of different surfactants on dispersibility. Consequently, this paper discusses the effect of different types of surfactants on the dispersibility of CNTs and presents several perspectives for future research on dispersibility enhancement.
... Noble metals in bulk appear to have inert behavior, biocompatibility, and no significant interactions with other elements, which could make them ideal in biomedical applications [187]. Due to their interaction with external fields and the ease with which they are recovered, reused, or altered with magnetic manipulation, MNPs, namely magnetite and maghemite, are particularly appealing as components of multifunctional NMs, and the general biocompatibility of noble metal nanoparticles makes these materials the ideal combination for biomedical applications [186,188]. ...
This review focuses on the role of magnetic nanoparticles (MNPs), their physicochemical properties, their potential applications, and their association with the consequent toxicological effects in complex biologic systems. These MNPs have generated an accelerated development and research movement in the last two decades. They are solving a large portion of problems in several industries, including cosmetics, pharmaceuticals, diagnostics, water remediation, photoelectronics, and information storage, to name a few. As a result, more MNPs are put into contact with biological organisms, including humans, via interacting with their cellular structures. This situation will require a deeper understanding of these particles’ full impact in interacting with complex biological systems, and even though extensive studies have been carried out on different biological systems discussing toxicology aspects of MNP systems used in biomedical applications, they give mixed and inconclusive results. Chemical agencies, such as the Registration, Evaluation, Authorization, and Restriction of Chemical substances (REACH) legislation for registration, evaluation, and authorization of substances and materials from the European Chemical Agency (ECHA), have held meetings to discuss the issue. However, nanomaterials (NMs) are being categorized by composition alone, ignoring the physicochemical properties and possible risks that their size, stability, crystallinity, and morphology could bring to health. Although several initiatives are being discussed around the world for the correct management and disposal of these materials, thanks to the extensive work of researchers everywhere addressing the issue of related biological impacts and concerns, and a new nanoethics and nanosafety branch to help clarify and bring together information about the impact of nanoparticles, more questions than answers have arisen regarding the behavior of MNPs with a wide range of effects in the same tissue. The generation of a consolidative framework of these biological behaviors is necessary to allow future applications to be manageable.
... Anionic surfactants, better known as detergents in industrial applications, are formed of negatively charged polar headgroups (carboxylate, sulfate, and phosphate) stabilized by positive counterions (sodium, potassium, or ammonium) while cationic surfactants consist of a positively charged headgroup (quaternary ammonium) and a halide ion as a counterion. Moreover, zwitterionic surfactants possess both positive and negative charges and are very useful for obtaining vesicle morphologies (Lombardo et al., 2015;Soleimani Zohr Shiri et al., 2019). ...
In this chapter, the basic properties of nanosystems applied as carriers of active compounds are briefly described. Structurally, they can be grouped as colloidal carriers, vesicular carriers, or nanoparticulate carriers. The agricultural and food applications of nanocarriers for nutrient delivery, nutraceuticals, food additives, and antimicrobials are summarized. These systems provide a larger surface area for interaction with biological substrates, prevent undesirable interactions with food components, improve solubility and absorption, protect antimicrobials against environmental stress, and allow a targeted and controlled release. The diversity of nanocarriers allows us to use them according to the final objectives and types of food components.
... Micelles are formed by the self-assembly of amphiphilic polymers at the CMC [36][37][38][39]. This self-assembly of an amphiphilic polymer with a hydrophobic tail and hydrophilic head is referred to as a polymeric micelle [40][41][42][43]. Depending on the hydrophobic and hydrophilic segments and solvent conditions, the morphologies of micelles take different shapes, including spheres, tubules, inverse micelles, bottle-brush shapes, and so on [44]. ...
... When the hydrophilic head is faced inside while the hydrophobic tails are projected outside, this arrangement refers to a reverse micelle, as shown in Scheme 2 [40,[69][70][71]. The inverse micelle can form a nanostructure or undergo self-assembly in non-aqueous solutions [72]. ...
Self-assembly of amphiphilic polymers with hydrophilic and hydrophobic units results
in micelles (polymeric nanoparticles), where polymer concentrations are above critical micelle concentrations (CMCs). Recently, micelles with metal nanoparticles (MNPs) have been utilized in many bio-applications because of their excellent biocompatibility, pharmacokinetics, adhesion to biosurfaces, targetability, and longevity. The size of the micelles is in the range of 10 to 100 nm, and different shapes of micelles have been developed for applications. Micelles have been focused recently on bio-applications because of their unique properties, size, shape, and biocompatibility, which enhance
drug loading and target release in a controlled manner. This review focused on how CMC has been calculated using various techniques. Further, micelle importance is explained briefly, different types and shapes of micelles are discussed, and further extensions for the application of micelles are addressed. In the summary and outlook, points that need focus in future research on micelles are discussed. This will help researchers in the development of micelles for different applications.
