Effect of electrospinning process variables on the size of polymer fibers and bead-on-string structures established with a 2³ factorial design

• Paulina Korycka,
• Adam Mirek,
• Katarzyna Kramek-Romanowska,
• Marcin Grzeczkowicz and
• Dorota Lewińska

Beilstein J. Nanotechnol. 2018, 9, 2466–2478, doi:10.3762/bjnano.9.231

• ][8][9][10]. Not only do they concern the values but also the change of process parameters such as: polymer solution properties (type of polymer, type of solvent, solution viscosity [11], surface tension, conductivity [11][12], etc.) and process variables (electrical voltage delivered to the nozzle

• was also concluded that the properties of the polymer solution (concentration, viscosity and surface tension) had the biggest influence on the size of fibers obtained in the electrospinning process. In terms of solution concentration, the proportional relationship between the polymer concentration and

Surface energy of nanoparticles – influence of particle size and structure

• Dieter Vollath,
• Franz Dieter Fischer and
• David Holec

Beilstein J. Nanotechnol. 2018, 9, 2265–2276, doi:10.3762/bjnano.9.211

• Gibbs using the term “surface tension” [1][2]. In the meantime, it has become clear that in case of solids one has to distinguish between “surface energy” and “surface stress”. Both quantities are related by the Shuttleworth equation [3]. Since the surface stress, σ, exerts a pressure, p, on a curved

• this, the basic ideas of both approaches are explained in this paper. Approach based on classical thermodynamics and continuum considerations When Gibbs [1][2] introduced surface energy using the term surface tension he predicted a decrease of the surface energy with decreasing droplet size. As an

• , minor [3]. Based on this clarification, it is obvious that the lattice contraction data for small particles, abundant in the literature, may be used to calculate the size dependent surface stress, (see, e.g., [6][7][8]) but not, as it is done sometimes [9][10], to calculate the surface energy (“surface

Electrospun one-dimensional nanostructures: a new horizon for gas sensing materials

• Muhammad Imran,
• Nunzio Motta and
• Mahnaz Shafiei

Beilstein J. Nanotechnol. 2018, 9, 2128–2170, doi:10.3762/bjnano.9.202

• droplet into a cone shape, where surface tension reduces the surface area by keeping it in a spherical shape. When the charged repulsive expansion exceeds surface tension based contraction, a charged jet of the solution is ejected from the tip of the Taylor cone and travels toward the target surface [48

• sensing platforms (i.e., micro-electromechanical systems (MEMs)). The electrospinning process is governed by various parameters such as viscosity, conductivity, molecular weight of fiber components, surface tension of polymer solution, electric potential, working distance, and flow rate. Each parameter

Interaction-tailored organization of large-area colloidal assemblies

• Silvia Rizzato,
• Elisabetta Primiceri,
• Anna Grazia Monteduro,
• Adriano Colombelli,
• Angelo Leo,
• Maria Grazia Manera,
• Roberto Rella and
• Giuseppe Maruccio

Beilstein J. Nanotechnol. 2018, 9, 1582–1593, doi:10.3762/bjnano.9.150

• are not completely fixed in their positions on the substrates [29]. It is worth noting that the intensity of capillary forces increases with the particle radius and as the distance between two particles in a liquid is reduced: Fcap ≈ 2πσrc2(sin2θ) / r where σ is the surface tension of the liquid, θ is

Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces

• Sven Oras,
• Sergei Vlassov,
• Marta Berholts,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61

• ° and θTL = 60° [36] are the static contact angles of the liquid on substrate (–NH2) and tip, respectively and γLV = 7.28 × 10−2 N/m is the liquid (water) surface tension. For the given values the capillary forces are around 7 nN. From Equation 2, it can be deduced that for the low humidity there is no

Optimisation of purification techniques for the preparation of large-volume aqueous solar nanoparticle inks for organic photovoltaics

• Furqan Almyahi,
• Thomas R. Andersen,
• Nathan A. Cooling,
• Natalie P. Holmes,
• Matthew J. Griffith,
• Krishna Feron,
• Xiaojing Zhou,
• Warwick J. Belcher and
• Paul C. Dastoor

Beilstein J. Nanotechnol. 2018, 9, 649–659, doi:10.3762/bjnano.9.60

• spectroscopy-based method and by surface tension measurements of the nanoparticle ink filtrate; revealing that centrifugal ultrafiltration removed SDS at a higher rate than crossflow ultrafiltration even though a similar filter was applied in both cases (10,000 Da Mw cut-off). The influence of SDS

• at a dilution factor of 7.8 × 104, while crossflow purified inks did not reach a maximum efficiency until a dilution factor of 6.1 × 109. This difference was ascribed to the different wetting properties of the prepared inks and was further corroborated by surface tension measurements of the ASNP inks

• which revealed that the peak efficiencies for both methods occurred for similar surface tension values of 48.1 and 48.8 mN m−1. This work demonstrates that addressing the surface tension of large-volume ASNP inks is key to the reproducible fabrication of nanoparticle photovoltaic devices. Keywords

Ultralight super-hydrophobic carbon aerogels based on cellulose nanofibers/poly(vinyl alcohol)/graphene oxide (CNFs/PVA/GO) for highly effective oil–water separation

• Zhaoyang Xu,
• Huan Zhou,
• Sicong Tan,
• Xiangdong Jiang,
• Weibing Wu,
• Jiangtao Shi and
• Peng Chen

Beilstein J. Nanotechnol. 2018, 9, 508–519, doi:10.3762/bjnano.9.49

• aerogels with high porosity, small hole size and low surface energy. Obviously, the absorption capacity difference of the carbon aerogels was largely determined by the density of the carbon aerogel and surface tension of the solvents and oils. Additionally, the density, which demonstrates the quantity of

Engineering of oriented carbon nanotubes in composite materials

• Razieh Beigmoradi,
• Abdolreza Samimi and
• Davod Mohebbi-Kalhori

Beilstein J. Nanotechnol. 2018, 9, 415–435, doi:10.3762/bjnano.9.41

• polymer layer, manual alignment is preferred [41]. Based on the fundamental principles of this approach, another method for making thin films of CNTs has been developed using the same tools. Fluid containing CNTs is spread on a solid substrate using a spiral film applicator. The surface tension and

Periodic structures on liquid-phase smectic A, nematic and isotropic free surfaces

• Anna N. Bagdinova,
• Evgeny I. Demikhov,
• Nataliya G. Borisenko,
• Sergei M. Tolokonnikov,
• Gennadii V. Mishakov and
• Andrei V. Sharkov

Beilstein J. Nanotechnol. 2018, 9, 342–352, doi:10.3762/bjnano.9.34

• liquid surface [16][17][18][19][20]. In the article [16], a case was considered where periodic stripe structures occur on the charged liquid helium surface as a result of competition between electrostatic forces and surface tension. Qualitatively, our problem is similar to this case and can be described

Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting: combining renewable raw materials with clean fuels

• Stefanie Krüger,
• Michael Schwarze,
• Otto Baumann,
• Christina Günter,
• Michael Bruns,
• Christian Kübel,
• Dorothée Vinga Szabó,
• Rafael Meinusch,
• Verónica de Zea Bermudez and
• Andreas Taubert

Beilstein J. Nanotechnol. 2018, 9, 187–204, doi:10.3762/bjnano.9.21

• instrument software (Sol.I.D.) was employed for calculations of results supporting Washburn’s equation. A mercury surface tension of 0.48 N/m and a contact angle of intruded mercury of 140° were assumed. Reflection solid-state UV–vis spectrometry was done on a Perkin-Elmer (PE) Lambda 950 UV–vis spectrometer

Hyperthermic intracavitary nanoaerosol therapy (HINAT) as an improved approach for pressurised intraperitoneal aerosol chemotherapy (PIPAC): Technical description, experimental validation and first proof of concept

• Daniel Göhler,
• Stephan Große,
• Alexander Bellendorf,
• Thomas Albert Falkenstein,
• Mehdi Ouaissi,
• Jürgen Zieren,
• Michael Stintz and
• Urs Giger-Pabst

Beilstein J. Nanotechnol. 2017, 8, 2729–2740, doi:10.3762/bjnano.8.272

• temperature due to decreasing dynamic viscosity, density and surface tension of the liquid. To increase the droplet flux as well as the in-tissue drug penetration homogenously over the whole peritoneum, the HINAT-LAU aerosol is also unipolar-charged before entering the capnoperitoneum. For this purpose, an

Nanoprofilometry study of focal conic domain structures in a liquid crystalline free surface

• Anna N. Bagdinova,
• Evgeny I. Demikhov,
• Nataliya G. Borisenko and
• Sergei M. Tolokonnikov

Beilstein J. Nanotechnol. 2017, 8, 2544–2551, doi:10.3762/bjnano.8.254

• the elastic moduli of liquid crystals. The shear modulus, G, is given as where C and C1 are scaling constants depending on surfactant, t is the relative temperature, γ is the surface tension coefficient of the free surface with FCDs, and L is the FCD dimension. This relation underlines that the

• is physically related to the domain size and surface tension. This is very important for the analysis of the stable director field configurations and mechanisms behind their destruction in LC displays. Even in the case of a homogeneous director field orientation on solid substrates, FCDs can occur

Surfactant-induced enhancement of droplet adhesion in superhydrophobic soybean (Glycine max L.) leaves

• Oliver Hagedorn,
• Ingo Fleute-Schlachter,
• Hans Georg Mainx,
• Viktoria Zeisler-Diehl and
• Kerstin Koch

Beilstein J. Nanotechnol. 2017, 8, 2345–2356, doi:10.3762/bjnano.8.234

• roll off. Droplet adhesion can be improved by adding adjuvants, such as surfactants. Surfactants enhance the leaf surface wettability by reduction of the surface tension of applied liquids. Surfactants are amphiphilic molecules with a nonpolar, hydrophobic structural group together with a hydrophilic

Evaluation of preparation methods for suspended nano-objects on substrates for dimensional measurements by atomic force microscopy

• Petra Fiala,
• Daniel Göhler,
• Benno Wessely,
• Michael Stintz,
• Giovanni Mattia Lazzerini and
• Andrew Yacoot

Beilstein J. Nanotechnol. 2017, 8, 1774–1785, doi:10.3762/bjnano.8.179

• in surface tension causes the liquid to flow away from regions of low surface tension associated with a strong recirculation in the droplet, which removes particles from the contact line and moves them along the free surface toward the droplet centre. Rinsing method: Apart from the interruption of

Collembola cuticles and the three-phase line tension

• Håkon Gundersen,
• Hans Petter Leinaas and
• Christian Thaulow

Beilstein J. Nanotechnol. 2017, 8, 1714–1722, doi:10.3762/bjnano.8.172

• wetting states with any value of θ0 [26], but such structures are not a universal trait in these animals [5][6]. The upper limit of θ0 is about 120° for real surfaces, observed on perfluorinated polymers, or 156 ° for a theoretical surface with no surface tension [27]. Insect waxes fall in the range of 90

Surface functionalization of 3D-printed plastics via initiated chemical vapor deposition

• Christine Cheng and
• Malancha Gupta

Beilstein J. Nanotechnol. 2017, 8, 1629–1636, doi:10.3762/bjnano.8.162

• to substrates on a cooled stage where polymerization occurs. The molecular weight increases with decreasing substrate temperature and typical molecular weights are in the range of 50,000 to 200,000 [23][24]. The iCVD process is solventless and therefore effects of surface tension are avoided

A biofunctionalizable ink platform composed of catechol-modified chitosan and reduced graphene oxide/platinum nanocomposite

• Peter Sobolewski,
• Agata Goszczyńska,
• Małgorzata Aleksandrzak,
• Karolina Urbaś,
• Joanna Derkowska,
• Agnieszka Bartoszewska,
• Jacek Podolski,
• Ewa Mijowska and
• Mirosława El Fray

Beilstein J. Nanotechnol. 2017, 8, 1508–1514, doi:10.3762/bjnano.8.151

• can estimate the Z parameter (the reciprocal of the Ohnesorge number (Oh), the ratio of the Reynolds number (Re) to the square root of the Webber number (We)), which predicts stable drop formation [14]: where d is the nozzle diameter and ρ, γ, and η represent the density, surface tension, and

• viscosity of the ink, respectively. We were not able to measure directly the viscosity and surface tension of our ink as formulated. However, we were able to estimate the values of the parameters based on the values provided by Jang et al. for EG/water mixtures [14] and the viscosity of the chitosan polymer

Nanotopographical control of surfaces using chemical vapor deposition processes

• Meike Koenig and
• Joerg Lahann

Beilstein J. Nanotechnol. 2017, 8, 1250–1256, doi:10.3762/bjnano.8.126

• the elastic modulus of the polymer coating and the substrate. Haller et al. investigated the morphology of vapor-deposited polymers on liquid substrates (Figure 3) [29]. Depending on surface tension, liquid viscosity, deposition rate and deposition time, either film or particle formation was found

• . Particles tend to form if the surface tension interaction between the liquid and the polymer is energetically unfavorable, promoting aggregation of the polymer. If the interaction is ambiguous, particle formation is observed at low deposition rates and times and with low liquid viscosity. Introduction of

Study of the correlation between sensing performance and surface morphology of inkjet-printed aqueous graphene-based chemiresistors for NO₂ detection

• F. Villani,
• C. Schiattarella,
• T. Polichetti,
• R. Di Capua,
• F. Loffredo,
• B. Alfano,
• M. L. Miglietta,
• E. Massera,
• L. Verdoliva and
• G. Di Francia

Beilstein J. Nanotechnol. 2017, 8, 1023–1031, doi:10.3762/bjnano.8.103

• -printing process and to determine its jettability as ink. Surface tension, dispersion stability and aggregate size have been measured since the ink printability depends on these main parameters, which have to match the operating parameters of the employed printing system. Based on these considerations, the

• . Additionally, by monitoring the dispersion through the DLS analysis, its time-stability has been confirmed over two weeks. The surface tension has been measured and the obtained value is 26.30 mN/m, which falls into the operating range (20–40 mN/m) of the printhead of the inkjet system. As a result, the

• graphene ink-Si/SiO2 system was very poor inducing a not continuous and not controlled deposition. This is expected since the measured surface energy of the substrate (30.95 mN/m) is comparable with the surface tension of the solution (26.30 mN/m). Hence, an UV–ozone treatment of the substrate was

Synthesis of coaxial nanotubes of polyaniline and poly(hydroxyethyl methacrylate) by oxidative/initiated chemical vapor deposition

• Alper Balkan,
• Efe Armagan and
• Gozde Ozaydin Ince

Beilstein J. Nanotechnol. 2017, 8, 872–882, doi:10.3762/bjnano.8.89

• effect and surface tension. Thus, vapor-phase polymerization techniques have emerged for the deposition of conducting polymers that facilitate the fabrication of conformal polymeric structures [21][22]. Polyaniline (PANI) is one of the well-known conducting polymers with applications in supercapacitors

Measuring adhesion on rough surfaces using atomic force microscopy with a liquid probe

• Juan V. Escobar,
• Cristina Garza and
• Rolando Castillo

Beilstein J. Nanotechnol. 2017, 8, 813–825, doi:10.3762/bjnano.8.84

• break during pull-off and results in a small residual water droplet on the surface. In the present study, we choose mercury as the liquid because it presents many advantages. Hg possesses a very high surface tension and negligible evaporation, plus it is relatively easy to attach to a tipless cantilever

• , while the drop deformation will also be considered to be elastic, Fd = −kdδd [10], which is a consequence of the high surface tension of mercury (ca. 486.5 mN/m); kc and kd are the force constants, and δd and δc correspond to the deformation of cantilever and drop, respectively. These relevant distances

• experiments of cylindrical nanofibers dipped in liquids of different γ, where γ is the liquid–vapor surface tension [36]. For contact angles above 50–60°, the spring constants are almost insensible to the contact angle, and although these authors did not explore angles corresponding to hydrophobic surfaces

Nanoscale isoindigo-carriers: self-assembly and tunable properties

• Tatiana N. Pashirova,
• Andrei V. Bogdanov,
• Lenar I. Musin,
• Julia K. Voronina,
• Irek R. Nizameev,
• Marsil K. Kadirov,
• Vladimir F. Mironov,
• Lucia Ya. Zakharova,
• Shamil K. Latypov and
• Oleg G. Sinyashin

Beilstein J. Nanotechnol. 2017, 8, 313–324, doi:10.3762/bjnano.8.34

• do not decrease the surface tension of the solvent (52 mN/m). They are surface-inactive compounds (Figure S9, Supporting Information File 1). The study of the entrapment of hydrophobic probes is a generally accepted assay for the potential of soft materials to be used as nanocontainers for

• aggregates can be formed. The surface tension of SDS solutions admixed with 2а and 3 are given in Figure 6. The formation of mixed structures of SDS and isoindigo derivative 2a is observed in a lower concentration range compared to single SDS micelles. This is supported by the left-shift in the surface

• . Chemical shifts (CSs) were calculated by the GIAO method at the same level of theory. All data were referred to TMS (13C) and NH3 (15N) chemical shifts, which were calculated under the same conditions. Surface tension Surface tension measurements were performed using the du Nouy ring detachment method

Structural and tribometric characterization of biomimetically inspired synthetic "insect adhesives"

• Matthias W. Speidel,
• Malte Kleemeier,
• Andreas Hartwig,
• Klaus Rischka,
• Angelika Ellermann,
• Rolf Daniels and
• Oliver Betz

Beilstein J. Nanotechnol. 2017, 8, 45–63, doi:10.3762/bjnano.8.6

• walls of the outlet ductule [4][20][26]. Moreover, within the lipoid fraction itself, both the specific constitution and the mixing ratio of the various hydrocarbon molecules might also largely influence their adhesive performance possibly via viscosity and surface tension effects, molecular re

• phase. In combination with the use of the ionic surfactant SDS (which lowers the surface tension even further), this probably explains the low friction values of these emulsions. By contrast, two of the oil-in-water (o/w) emulsions (SG2, OG2) showed increased friction values; this can be ascribed to

Photothermal effect of gold nanostar patterns inkjet-printed on coated paper substrates with different permeability

• Mykola Borzenkov,
• Anni Määttänen,
• Petri Ihalainen,
• Maddalena Collini,
• Elisa Cabrini,
• Giacomo Dacarro,
• Piersandro Pallavicini and
• Giuseppe Chirico

Beilstein J. Nanotechnol. 2016, 7, 1480–1485, doi:10.3762/bjnano.7.140

• aqueous PEGylated GNS solution (70 vol %) in order to adjust suitable viscosity and surface tension for inkjet printing (1.92 cP and 40 mN/m, respectively) as reported previously [27][28]. Notably, GNS decorated with PEG-SH become soluble in a variety of solvents, from water to hydrophobic ones, due to

Three-gradient regular solution model for simple liquids wetting complex surface topologies

• Sabine Akerboom,
• Marleen Kamperman and
• Frans A. M. Leermakers

Beilstein J. Nanotechnol. 2016, 7, 1377–1396, doi:10.3762/bjnano.7.129

• evaluate the surface tension γ, which is given in units kBT/b2, numerically, as discussed in section S1 of Supporting Information File 1. In Figure 3B we prove that near the critical point (i) the surface tension, (ii) the width of the interface and (iii) Δφ as found by our numerical solution accurately

• partial wetting states, where the macroscopically thick film represents the situation under a drop, and the thin film is found far away from the drop where a gas-like film resides on the substrate. As for each solution along the isotherm we have the surface tension accurately available from the self

• interface, the so-called surface of tension, for which a small notional change of the radius does not influence the value of the surface tension. For this special case the Laplace equation simplifies to Equation 3, and the value of the interfacial tension does not deviate much from the planar value. From