“…A signal at 669 cm −1 in the MUA-NPLs (MUA stacks: 669 cm −1 ) can be assigned to Cd-S vibrations known from CdS nanoparticles around 665 cm −1 . [40][41][42] So both the XPS and IR verify the binding of the MUA to the CdSe-NPLs in the MUA-NPLs and MUA-stacks through the former thiol head group by the formation of R-S-Cd species being in accordance with literature. [24,26,27] Hence, to monitor the possible bridging of NPLs in the MUA-stacks through the MUA ligand forming a Cd-S-(CH 2 ) 10 -COO-Cd species, the formation of a carboxylate species bound to Cd needs to be monitored.…”
Section: Bridging Of Npls Through Ligandssupporting
Since their discovery, cadmium chalcogenide nanoplatelets (NPLs) gained a lot of interest, not only due to their beneficial characteristic, but also because of their high affinity to self‐assemble into ordered stacks. Interestingly, the stacks showed both the properties of the single NPLs and new collective features, such as charge carrier transport within the stacks. Until now, the stacking was, to the best of the knowledge, only performed in non‐polar media mostly through the addition of antisolvents with higher polarity. Due to the fact, that many applications (e.g., photocatalysis) or procedures (such as gelation) occur in water, a route to self‐assemble stacks directly in aqueous solution is needed. In this work a new synthesis route is thus introduced to produce stacks directly in aqueous media. The NPLs are phase transferred with mercaptocarboxylic acids to an aqueous KOH solution followed by an addition of less polar antisolvents to initialize the stacking (e.g., tetrahydrofuran). Furthermore, a mechanism of the stacking as well as four possible driving forces involved in the process are proposed supported by transmission electron microscopy, dynamic light scattering, infrared spectroscopy, and x‐ray photoelectron spectroscopy measurements.
“…A signal at 669 cm −1 in the MUA-NPLs (MUA stacks: 669 cm −1 ) can be assigned to Cd-S vibrations known from CdS nanoparticles around 665 cm −1 . [40][41][42] So both the XPS and IR verify the binding of the MUA to the CdSe-NPLs in the MUA-NPLs and MUA-stacks through the former thiol head group by the formation of R-S-Cd species being in accordance with literature. [24,26,27] Hence, to monitor the possible bridging of NPLs in the MUA-stacks through the MUA ligand forming a Cd-S-(CH 2 ) 10 -COO-Cd species, the formation of a carboxylate species bound to Cd needs to be monitored.…”
Section: Bridging Of Npls Through Ligandssupporting
Since their discovery, cadmium chalcogenide nanoplatelets (NPLs) gained a lot of interest, not only due to their beneficial characteristic, but also because of their high affinity to self‐assemble into ordered stacks. Interestingly, the stacks showed both the properties of the single NPLs and new collective features, such as charge carrier transport within the stacks. Until now, the stacking was, to the best of the knowledge, only performed in non‐polar media mostly through the addition of antisolvents with higher polarity. Due to the fact, that many applications (e.g., photocatalysis) or procedures (such as gelation) occur in water, a route to self‐assemble stacks directly in aqueous solution is needed. In this work a new synthesis route is thus introduced to produce stacks directly in aqueous media. The NPLs are phase transferred with mercaptocarboxylic acids to an aqueous KOH solution followed by an addition of less polar antisolvents to initialize the stacking (e.g., tetrahydrofuran). Furthermore, a mechanism of the stacking as well as four possible driving forces involved in the process are proposed supported by transmission electron microscopy, dynamic light scattering, infrared spectroscopy, and x‐ray photoelectron spectroscopy measurements.
“…These agglomerates may result in porosity due to inadequate matrix fusion, consequently degrading the properties. The morphology changes with addition of FA into the PEK matrix can also be understood and correlated with the change in thermal properties observed from thermogravimetric analysis (TGA) and coefficient of thermal expansion (CTE), detailed by Kumar et al 5 Figure 4.FE-SEM images of the composites FA10, FA30 and FA50 (a, c and e) showing lower magnification images, respectively (b, d & f) showing the higher magnification images for the same.…”
Section: Resultsmentioning
confidence: 58%
“…7,35 The higher storage modulus of the composite is also consistent with the higher thermal conductivity (and the crystallinity percentage) of this composite as reported by the authors in an earlier work. 5 It is well known that stiffer materials tend to have higher acoustic velocity and better heat conduction. 7,36 Along with this, composites were annealed at 200°C for 2°h in vacuum oven before the measurement of viscoelastic behaviour of samples.…”
Section: Resultsmentioning
confidence: 99%
“…The other relevant information pertaining to the DSC curve can be referred to in our earlier publication. 5 Figure 8.DSC thermograph of the composites FA0, FA10 and FA30 before and after annealing at 200°C for 2 h.…”
Section: Resultsmentioning
confidence: 99%
“…3 PEK is semi-crystalline polymer having glass transition temperature (T g ) around 160°C −165°C and melting temperature (T m ) around 360°C - 370°C. 4,5 It has continuous operating temperature up to 280°C and under short-term loads it can function up to 350°C. 6 Figure 1.A schematic representation of the chemical structure of PEK.…”
Poly(ether-ketone)/fly ash (FA) composites reinforced with 0-30 wt% FA were fabricated using ball milling followed by hot compaction. The composites were investigated for mechanical and viscoelastic properties. Scanning electron microscopy revealed excellent dispersion and good adhesion of FA particles with the matrix. The addition of FA increased the microhardness by 70% and the storage modulus (below glass transition) by 75%. The reinforcing efficiency was better above the glass transition, which increased to around 177% at 250°C. This research indicates that the FA can be used as an alternative reinforcement of costly ceramic powder for the electronic packaging substrate or printed circuit board applications.
Poly (vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)] has three crystal forms, including paraelectric α, ferroelectric β, and γ phases. In previous studies, the properties and performances of P(VDF‐TrFE) have been the focus of research. However, the formation mechanism and regulation mode of various crystal forms remain unclear. Therefore, it is an important topic for further research to elucidate, summarize, and prospect the polymorphism of P(VDF‐TrFE) and regulate the crystal forms. This review systematically summarizes the crystalline structure and phase transition between ferroelectric and paraelectric phase of P(VDF‐TrFE) crystals; discusses the influence of annealing, blending and electric field on the crystallinity, selection of polymorphic crystals, and phase transition behavior between them; reviews the effects of annealing, melt‐recrystallization, substrate and nanoconfinement on the crystal orientation. Finally, the effects of the crystal structure of P(VDF‐TrFE) on its properties are briefly summarized.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
