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Search for "polymer" in Full Text gives 769 result(s) in Beilstein Journal of Nanotechnology. Showing first 200.
Electrostatic pull-in application in flexible devices: A review
Beilstein J. Nanotechnol. 2022, 13, 390–403, doi:10.3762/bjnano.13.32
- collapse, the preparation technology is complex. Li et al. [30] prepared cantilever GR-NEM switches with two or three terminals using amorphous silicon as sacrificial layer. Sun et al. [6] prepared a three-terminal switch using PMMA polymer as the sacrifice layer. The graphene beam area was 2.5 µm × 0.5 µm
- kV output voltage using 3D printed conductive polylactic acid polymer. In 2021, they [101] integrated a lithium niobate crystal, a piezoelectric cantilever switch, and a capacitive load into a single printed circuit board (PCB). The output voltage ranges from 15.5 to 1480 V, and the cantilever switch
Micro- and nanotechnology in biomedical engineering for cartilage tissue regeneration in osteoarthritis
Beilstein J. Nanotechnol. 2022, 13, 363–389, doi:10.3762/bjnano.13.31
- -mimicking polymer and fabricated a 3D electrospun mat through electrospinning of PVA and sulfated alginate solutions. The results demonstrated that human bone marrow (hBM) MSCs attach appropriately and spread on the resulting nanofibrous mats. In addition, the results of type-II collagen expression and
- because they are not biodegradable and provide a more stable matrix in which osteoblasts can proliferate and deposit new ECM. The integration of CNTs into a polymer matrix would increase surface roughness and activate the mitogen-activated protein kinase (MAPK) pathway [128], which is responsible for
Interfacial nanoarchitectonics for ZIF-8 membranes with enhanced gas separation
Beilstein J. Nanotechnol. 2022, 13, 313–324, doi:10.3762/bjnano.13.26
- ., strong acids or bases or organic solvents) compared to polymer substrates. The particle size of α-Al2O3 on dense top layers of these disks is around 200 nm (information from Fraunhofer IKTS, Germany). The porosity of the disks was measured as 41.58% by mercury porosimeter measurements. The XRD patterns
- fabricated in this work showed a lower separation factor but a higher CO2 permeance. Dense polymer materials in MMMs tend to lower the gas permeance. Conclusion ZIF-8 membranes embedded in porous α-Al2O3 disks were successfully fabricated via a simple one-step and low-pressure interfacial synthesis method
The effect of metal surface nanomorphology on the output performance of a TENG
Beilstein J. Nanotechnol. 2022, 13, 298–312, doi:10.3762/bjnano.13.25
- of a metal and a polymer. There are different charge densities on different kinds of metal surface nanomorphology, which significantly influences the output performance of the TENG. Copper samples with different nanomorphology were obtained by controlling pH value, current density, electrolyte
- , such as template forming, plasma treatment, and chemical approaches. Previous studies mostly focused on the preparation process of the nanoscale morphology on the polymer surface [47][48][49]. The electrons on the polymer surface cannot be transferred to the conduction band and the charge cannot flow
- freely. Therefore, there is no high charge density on the tip surface of the polymer surface. Here, size and morphology of nanoscale copper were controlled by adjusting current density, temperature, pH value, and solution concentration during electrodeposition. The effects of different morphologies and
Systematic studies into uniform synthetic protein nanoparticles
Beilstein J. Nanotechnol. 2022, 13, 274–283, doi:10.3762/bjnano.13.22
- kcps). DLS results are the application of the Mark–Houwink equations within the software (Malvern Zetasizer Software 8.01.4906). The results generated from this makes assumptions regarding the intrinsic viscosity, which can only be an estimate since the local viscosity in polymer and/or protein
Effects of drug concentration and PLGA addition on the properties of electrospun ampicillin trihydrate-loaded PLA nanofibers
Beilstein J. Nanotechnol. 2022, 13, 245–254, doi:10.3762/bjnano.13.19
- than that of PLA since the increase in polymer molecular weight increases the viscosity, causing an increase in nanofiber diameter [14][15][16]. In other studies conducted on PLA/PLGA nanofibers, it was found that an increase in the viscosity of the solutions caused an increase in nanofiber diameters
- [8]. It was also claimed that the viscosity, which is related to the molecular weight of the polymer and the concentration of the polymer solution, is one of the most effective parameters to tune fiber diameters [11]. The nanofiber diameter is also greatly affected by changes in polymer structure [17
- ][18] and crystallization properties of the polymer [19]. Since the crystallinity of PLGA is known to be lower than that of PLA [20] and its structure is different, the increase in diameter with the addition of PLGA may be related to the lower crystallinity and different structure of PLGA. In our
Engineered titania nanomaterials in advanced clinical applications
Beilstein J. Nanotechnol. 2022, 13, 201–218, doi:10.3762/bjnano.13.15
- demonstrated enhanced osseointegration [58]. Additionally, drug release kinetics and duration from titania nanotubes (TNTs) can be controlled by modifying nanotube dimensions, surface chemistry, or by a polymer coating on the TNT implant surface through dip coating or plasma polymerization. Losic and co
- augmenting better attachment of drug molecules, and the drug release profile was extended to more than 15 days by minimizing the burst release effect [59]. Polycaprolactone is a semi-crystalline biodegradable polymer used as a drug carrier, packaging material, and 3D scaffold for bone tissue engineering
- . However, it is hydrophobic and poor cell adhesion has been reported. In a study of Kiran et al., TiO2 nanoparticles (0, 2, 5, and 7 wt %) were suspended in polycaprolactone forming a polymer/ceramic hybrid composite (PCL/TiO2), which was then used as a coating over biomedical grade commercial pure
Piezoelectric nanogenerator for bio-mechanical strain measurement
Beilstein J. Nanotechnol. 2022, 13, 192–200, doi:10.3762/bjnano.13.14
- through three different PVDF solutions (12, 14, and 16 wt %). The secondary electron images, taken at 10,000× and 40,000×, magnifications of prepared PVDF electrospun films from a 12 wt % polymer solution are shown in Figure 2A. The images show that the nanofibers have a more bead-on-string-like structure
- than the nanofibers obtained from 14 wt % solution (Figure 2B) due to incomplete solvent evaporation. The optimum polymer solution concentration is essential to obtain defect-free smooth fibers [14][37]. The nanofibers obtained from 16 wt % solution were smooth and presented a bead-free morphology
- high concentration of polymer solution. During evaporation of the solvent, polymer chains are more likely to form crystalline structures because they are closer together than in the solutions with lower concentration Also, when the polymer amount increases in the solution it increases generation
A comprehensive review on electrospun nanohybrid membranes for wastewater treatment
Beilstein J. Nanotechnol. 2022, 13, 137–159, doi:10.3762/bjnano.13.10
- fiber functionalization through blending the functionalizing material with the polymer prior to electrospinning, post-spinning surface functionalization, or the use of a coaxial electrospinning setup make electrospinning a superior technique for membrane fabrication [2]. The smaller size endows the
- polymers have shown a considerable enhancement of their properties and performances when compared to the as-spun fiber membranes [3][4]. The versatility of electrospinning has allowed for the fabrication of many synthetic and natural polymer membranes [5], and ceramic nanofibers as well [6]. The most
- common synthetic polymer membranes such as polycaprolactone (PCL), polyacrylonitrile (PAN), polyacrylic acid (PAA), polysulfones (PSF), polyimides (PI), polyvinyl alcohol (PVA), polystyrene (PS), polyethylene oxide (PEO), poly(vinylidene fluoride) (PVDF) and natural polymers such as gelatin, keratin
A photonic crystal material for the online detection of nonpolar hydrocarbon vapors
Beilstein J. Nanotechnol. 2022, 13, 127–136, doi:10.3762/bjnano.13.9
- [14]. Most of the configuration changes of the photonic bandgap in opal and inverse opal structures occur due to swelling or compression of the polymer matrix or gel. To date, four main methods for the modification of photonic crystals are used for the creation of stimuli-responsive materials: (a
- ) formation of a sensitive polymer matrix, (b) impregnation of the reagent, (c) immobilization of the reagent and (d) preparation of the sensor elements from molecularly imprinted polymers. Organic solvents are usually detected by using polymer matrix sensors (Table 1) through matrix interaction [7][8][9][15
- into the polymer matrix (Figure 5). The effect of n-decane vapor does not lead to a significant change in the sensor color, but only shifts the PBG by just ≈10 nm, nevertheless, the approach proposed here allows one to detect slight changes in the sensor color. Aromatic and aliphatic hydrocarbons were
Tin dioxide nanomaterial-based photocatalysts for nitrogen oxide oxidation: a review
Beilstein J. Nanotechnol. 2022, 13, 96–113, doi:10.3762/bjnano.13.7
- new insights into the underlying mechanism of heterojunction photocatalysts, especially those with Z-shaped interfaces [76]. Polyaniline (PANI) is a conducting polymer and compared to g-C3N4, PANI is inexpensive and easy to synthesize. Bui et al. [35] presented a SnO2/PANI nanocomposite for
- photocatalytic mechanisms, and the polymer photodegradation of the resulting nanocomposite using DFT techniques. The results confirmed that the interaction between NO and PANI is indeed a hydrogen bond and photogenerated holes serve as the primary factor of the photocatalytic NO removal [35]. Moreover, this
Theranostic potential of self-luminescent branched polyethyleneimine-coated superparamagnetic iron oxide nanoparticles
Beilstein J. Nanotechnol. 2022, 13, 82–95, doi:10.3762/bjnano.13.6
- luminescent polymer. Therefore, it is usually tagged with an organic fluorophore to be optically tracked. Recently, we developed branched PEI (bPEI) superparamagnetic iron oxide nanoparticles (SPION@bPEI) with blue luminescence 1200 times stronger than that of bPEI without a traditional fluorophore, due to
- recently due to a very weak luminescence. Lin et al. synthesized mostly linear PEI and demonstrated a siRNA delivery with this luminescent polymer [27]. Sun et al. utilized the luminescence of branched PEI as the imaging modality in polymeric quantum dots (PDOTs) formed from amphiphilic polyethyleneimine
- in many in vitro studies including, for example, flow cytometry or fluorescence imaging, since the luminescence of the polymer was not detected [18][33][34]. Unfortunately, the luminescence of the fluorophores (dye or quantum dots) that are active in the visible range is usually significantly reduced
Nanoscale friction and wear of a polymer coated with graphene
Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4
- challenging problem due to the complex viscoelastic properties and structure. Using molecular dynamics simulations, we investigate how a graphene sheet on top of the semicrystalline polymer polyvinyl alcohol affects the friction and wear. Our setup is meant to resemble an AFM experiment with a silicon tip. We
- have used two different graphene sheets, namely an unstrained, flat sheet, and one that has been crumpled before being deposited on the polymer. The graphene protects the top layer of the polymer from wear and reduces the friction. The unstrained flat graphene is stiffer, and we find that it constrains
- the polymer chains and reduces the indentation depth. Keywords: friction; graphene; molecular dynamics; polymer; Introduction Graphene is a two dimensional material that has remarkable properties, both electronic [1][2] and mechanical [3][4]. Even before anything was known about graphene, the
Sputtering onto liquids: a critical review
Beilstein J. Nanotechnol. 2022, 13, 10–53, doi:10.3762/bjnano.13.2
Biocompatibility and cytotoxicity in vitro of surface-functionalized drug-loaded spinel ferrite nanoparticles
Beilstein J. Nanotechnol. 2021, 12, 1339–1364, doi:10.3762/bjnano.12.99
- the polymer, thereby rapidly releasing the drug from NPs into the cytosol [36]. Functionalized MFe2O4 NPs cause cytotoxicity in vitro The sulforhodamine B (SRB) assay was performed using HepG2 and HT144 cells to screen the cytotoxic potential of functionalized MFe2O4 (M = Fe, Co, Ni, Zn) NPs. The
- controls. The efficient retention of polymer-functionalized NPs in cancer cells, with the help of the EPR effect and a leaky vasculature system (pore diameter = 100 nm–2 µm) [7], reduces their nonspecific biological interactions with plasma proteins, contributing to a higher bioavailability [37]. SRB
- ZS (Malvern Instruments, 69 UK) and the uniform size distribution by gel electrophoresis (GE BIORAD). Drug attachment and drug release analyses were performed by using UV–vis spectroscopy (Thermo Scientific Evo 220). Phase transfer, polymer coating, and purification of MFe2O4 (M = Fe, Co, Ni, Zn) NPs
Polarity in cuticular ridge development and insect attachment on leaf surfaces of Schismatoglottis calyptrata (Araceae)
Beilstein J. Nanotechnol. 2021, 12, 1326–1338, doi:10.3762/bjnano.12.98
- reducing the frictional forces experienced when they walk on the leaves and might also provide mechanical stability to the growing plant organs. Here, we have studied the development of cuticular ridges on adaxial leaf surfaces of the tropical Araceae Schismatoglottis calyptrata. We used polymer replicas
- study, we have used polymer replicas of the S. calyptrata leaf surfaces at various ontogenetic stages for morphometric analyses. Polymer replication of the leaf surfaces helps to avoid artifacts arising from leaf dehydration during time-consuming microscopical analyses, especially with regard to the
- factor enabling the efficient separation of plant material from the epoxy negative molds during polymer replication. The third level is characterized by aged and uniformly aligned low aspect ratio ridges in a labyrinth-type arrangement (at stages 4 and 5) in H. brasiliensis (Supporting Information File 1
Enhancement of the piezoelectric coefficient in PVDF-TrFe/CoFe2O4 nanocomposites through DC magnetic poling
Beilstein J. Nanotechnol. 2021, 12, 1262–1270, doi:10.3762/bjnano.12.93
- temperatures. This process, usually referred to as electrical poling, requires the deposition of contact electrodes on the sample surface and the use of high-voltage apparatus. In the present work, in order to overcome these constraints, we have produced, characterized, and studied a polymer nanocomposite
- constant and good piezoelectric properties suitable for the fabrication of flexible piezoelectric nanogenerators [1][2][3][4][5][6][7]. One of the most extensively investigated piezoelectric polymers is poly(vinylidene fluoride) (PVDF). This polymer has attracted a lot of interest due to its excellent
- is well known that PVDF is characterized by four main polymorph phases, namely α, β, γ, and δ [12]. Due to its high thermodynamic stability at room temperature the α phase is the predominant one. However, the α phase does not contribute to the piezoelectricity of the polymer, whereas the γ and δ
Electrical, electrochemical and structural studies of a chlorine-derived ionic liquid-based polymer gel electrolyte
Beilstein J. Nanotechnol. 2021, 12, 1252–1261, doi:10.3762/bjnano.12.92
- Technology, Shirgaon, Virar East, Maharastra, 401305, India Department of Physics, School of Physical Sciences, Mahatma Gandhi Central University, Bihar-845401, India 10.3762/bjnano.12.92 Abstract In the present article, an ionic liquid-based polymer gel electrolyte was synthesized by using poly(vinylidene
- fluoride-co-hexafluoropropylene) (PVdF-HFP) as a host polymer. The electrolyte films were synthesized by using the solution casting technique. The as-prepared films were free-standing and transparent with good dimensional stability. Optimized electrolyte films exhibit a maximum room-temperature ionic
- conductivity of σ = 8.9 × 10−3 S·cm−1. The temperature dependence of the prepared polymer gel electrolytes follows the thermally activated behavior of the Vogel–Tammann–Fulcher equation. The total ionic transference number was ≈0.91 with a wider electrochemical potential window of 4.0 V for the prepared
The effect of cobalt on morphology, structure, and ORR activity of electrospun carbon fibre mats in aqueous alkaline environments
Beilstein J. Nanotechnol. 2021, 12, 1173–1186, doi:10.3762/bjnano.12.87
- respective signal intensities of the XPS C 1s range of the fibres is considered as shown in Figure 6. As expected for an increasing graphitisation, the amount of graphitic carbon (sp2) increases with carbonisation temperature, while the amount of sp3 carbon, expected in more amorphous or polymer-like samples
Assessment of the optical and electrical properties of light-emitting diodes containing carbon-based nanostructures and plasmonic nanoparticles: a review
Beilstein J. Nanotechnol. 2021, 12, 1078–1092, doi:10.3762/bjnano.12.80
- a uniform thin film. Some of the commonly used polymers and metal oxides for ETL are PBD, PBD-PMMA, BND, ZnO, SnO2, and TiO2 [69][70][71]. Improvements in the device performance have been reported, when using polymer–MWNT nanocomposite-based ETL. For example, Fournet et al. have investigated the
- (Figure 7) present the best results in terms of luminance and EL emission. In addition, the electron conductivity of the device is increased by four orders of magnitude. Concerning graphene–polymer nanocomposites, Choudhary et al. have inserted MoS2 and graphene oxide NP into a polyaniline ETL [72]. The
- , the device with 2–3% Ag-doped ZnO EIL shows maximum luminance of 10982 cd/m2, maximum current efficiency of 41.0 cd/A, and EQE of 15.2%. The addition of AgNP to PBD-based ETL enhances the green emission [75]. Kandulna et al. have addressed the effect of plasmonic NP on hybrid metal oxide–polymer
Use of nanosystems to improve the anticancer effects of curcumin
Beilstein J. Nanotechnol. 2021, 12, 1047–1062, doi:10.3762/bjnano.12.78
- is distributed within a polymeric matrix (i.e., surrounded by the polymer) they are referred to as nanocapsules. Alternatively, if the drug is homogeneously dispersed in the polymeric matrix they are called nanospheres [78][79]. Their main advantages include their reactivity, surface area, stability
- min), which was associated with the ammonium groups present in the salts of the polymer material. Previous studies have reported that 90% of CUR at pH 7.4 degrades in 30 min [85], so the system developed by Umerska et al. [84] would increase its residence time. Polymeric nanoparticles sensitive to pH
- ± 12.25 nm, EE% 78.04 ± 0.54 >70% CUR). This was associated with the compatibility of the compound with the lipid medium and the presence of the surfactant in the polymer formulation (which has been reported to affect the % EE). In addition, they reported better cellular uptake of SLN, which was
An overview of microneedle applications, materials, and fabrication methods
Beilstein J. Nanotechnol. 2021, 12, 1034–1046, doi:10.3762/bjnano.12.77
- on hydrogel-forming polymer microneedles [16][17][18]. Microneedle patch technology has the potential to overcome the challenges involved in mass vaccination against COVID-19 across the world and has already shown promising achievements in delivering lyophilised or liquid formulation-based vaccines
- and released as the microneedles dissolve [34][37]. The main limitation of dissolvable microneedles is the limited choice of drugs that can be encapsulated into dissolvable polymer or polymer–sugar combinations [34][36], and the short time and low volume of drug delivery. Dissolvable polymer
- methods, notably DRIE. Drawing lithography has been used for high aspect ratio microneedles of heights 1600, 1200, and 600 μm [80][81]. This technique involves spin coating of a viscoelastic thermosetting polymer such as SU-8 epoxy resin, followed by thermal curing and controlled drawing of the material
Progress and innovation of nanostructured sulfur cathodes and metal-free anodes for room-temperature Na–S batteries
Beilstein J. Nanotechnol. 2021, 12, 995–1020, doi:10.3762/bjnano.12.75
- cathode is reported to display a capacity of 153 mAh·g−1 after 500 cycles at 1C [39], while the latter has 257 mAh·g−1 after 200 cycles at 1C [40]. This problem is a consequence of the low sulfur content of the polymer, which is usually less than 50 wt % and the limited redox reactivity of sulfur [38][41
- instance, the development of polymer electrolytes, additives, salts, or specific materials that can be used in the preparation of components and conformation of elements of the battery. The analysis of the patent search results clearly shows a lack of specific patents dealing with the production of cathode
Self-assembly of Eucalyptus gunnii wax tubules and pure ß-diketone on HOPG and glass
Beilstein J. Nanotechnol. 2021, 12, 939–949, doi:10.3762/bjnano.12.70
- interface, covers all aerial non-lignified parts of higher plants [1]. It is an extracellular membrane of epidermal cells, consisting of a matrix of the polymer cutin and a mixture of hydrophobic compounds, the cuticular waxes [2][3]. This interface is a multifunctional surface optimized by evolution to
The role of deep eutectic solvents and carrageenan in synthesizing biocompatible anisotropic metal nanoparticles
Beilstein J. Nanotechnol. 2021, 12, 924–938, doi:10.3762/bjnano.12.69
- synthesis methods have been developed for environmental applications, such as biohydrogen production and chromium deionization [15][16][17][18]. In addition, polymer-based nanoparticles showed low drug loading and encapsulation efficiency. The acidic nature of poly(lactic-co-glycolic acid) is not suitable
- for certain drugs and bioactive molecules and make the polymer prone to a higher enzymatic degradation rate [19]. This is why there is a need for novel synthetic routes for synthesizing safe plasmonic metal nanoparticles maintaining high yield and monodispersity with tunable size and morphology
- application. The following section of the review focuses on DESs and carrageenan, a class of emerging green solvents and a carbohydrate polymer for synthesizing safe plasmonic nanomaterials. Deep eutectic solvents in nanotechnology The preparation of DESs involves mixing solid organic precursors with high
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