Plant growth regulation by seed coating with films of alginate and auxin-intercalated layered double hydroxides

• Vander A. de Castro,
• Valber G. O. Duarte,
• Danúbia A. C. Nobre,
• Geraldo H. Silva,
• Vera R. L. Constantino,
• Frederico G. Pinto,
• Willian R. Macedo and
• Jairo Tronto

Beilstein J. Nanotechnol. 2020, 11, 1082–1091, doi:10.3762/bjnano.11.93

• diversity of crops and cultivation environments, it is necessary to seek more efficient modes of application, which lead to a homogeneous distribution and promote a sustained release according to the plants demand. Seed coating, using films containing a biodegradable polymer and auxins intercalated into

• auxin 1-naphthalenoacetic acid (ZnAl-NAA-LDH), (ii) the coating of bean seeds (Phaseolus vulgaris L.) with composite films produced from mixtures of alginate polymer and ZnAl-NAA-LDH, and (iii) the evaluation of the plant response by bioassays. The hybrid ZnAl-NAA-LDH was characterized by a set of

• five samples. One was the control without polymer coating. The other four samples were coated with pure alginate; alginate and ZnAl-CO3-LDH, alginate and NAA, or alginate and ZnAl-NAA-LDH, with four replications. Six bean seeds previously coated with polymer (as described in Table 1) were sown in each

Wet-spinning of magneto-responsive helical chitosan microfibers

• Dorothea Brüggemann,
• Johanna Michel,
• Naiana Suter,
• Matheus Grande de Aguiar and
• Michael Maas

Beilstein J. Nanotechnol. 2020, 11, 991–999, doi:10.3762/bjnano.11.83

• dressings [36], and nanohydroxyapatite was embedded into chitosan fibers for bone tissue engineering applications [37]. Likewise, magnetic iron oxide particles have been blended with chitosan to prepare electrospun composite fibers [38][39] to form magneto-responsive polymer nanocomposites for bone tissue

Effect of magnetic field, heat generation and absorption on nanofluid flow over a nonlinear stretching sheet

• Santoshi Misra and
• Govardhan Kamatam

Beilstein J. Nanotechnol. 2020, 11, 976–990, doi:10.3762/bjnano.11.82

• the way for substantial research in this field. Sheet stretching involves analysis using both linear and nonlinear equations (e.g., the polymer extrusion process) as reflected in the numerical study by Rana and Bhargava [7]. This study was extended by Das [8] and Hayat et al. [9], who used partial

A 3D-polyphenylalanine network inside porous alumina: Synthesis and characterization of an inorganic–organic composite membrane

• Jonathan Stott and
• Jörg J. Schneider

Beilstein J. Nanotechnol. 2020, 11, 938–951, doi:10.3762/bjnano.11.78

• ) in porous alumina membranes (ALOX-membranes) with respect to different solvent mixtures (tetrahydrofuran (THF) and dichloromethane (DCM)). It was found that increasing the volume fraction of DCM leads to an increasing amount of fibrillar polymer structures within the porous ALOX-membrane. A three

• -dimensional fibrillar network with intrinsic porosity was formed in DCM, whereas in THF, a dense and smooth polypeptide film was observed. A post-treatment with a mixture of chloroform and dichloroacetic acid leads to rearrangement of the morphology of the grafted polymer films. The analysis by scanning

• electron microscopy (SEM), near-infrared spectroscopy (NIR) and contact angle measurements (CA) reveals a change in morphology of the grafted polymer films, which is due to the rearrangement of the secondary structure of the polypeptides. No significant loss of the surface-grafted polypeptides was

Key for crossing the BBB with nanoparticles: the rational design

• Sonia M. Lombardo,
• Marc Schneider,
• Akif E. Türeli and
• Nazende Günday Türeli

Beilstein J. Nanotechnol. 2020, 11, 866–883, doi:10.3762/bjnano.11.72

• the brain by local delivery. Local delivery consists of directly delivering the drug to the brain by injection via a catheter or with the help of a convection-enhanced delivery system. Biodegradable polymer implants can also be used for sustained release of the drug [9][10]. These procedures require

• nature of the nanoparticle core composition, not only of the polymer, but also of the API [54]. The ability of surfactants to interact with apolipoproteins was confirmed in another study by Petri et al., where the efficacy of PBCA nanoparticles loaded with doxorubicin and coated with either PS80 or P188

• ., the polymer and API in use. Surface functionalization To be able to cross the BBB by RMT, nanoparticle surfaces can be functionalized with specific ligands. This approach has been well studied and a multitude of different ligands has been tested. Some of the recent advances for this approach are

Templating effect of single-layer graphene supported by an insulating substrate on the molecular orientation of lead phthalocyanine

• K. Priya Madhuri,
• Abhay A. Sagade,
• Pralay K. Santra and
• Neena S. John

Beilstein J. Nanotechnol. 2020, 11, 814–820, doi:10.3762/bjnano.11.66

• -on configuration are still observed. In the case of CVD graphene transferred on to substrates by the polymer method, it has been reported that the presence of polymer residues can cause edge-on orientation for pentacene on graphene [11]. However, in this work, effort has been taken to remove any

• polymer residues via thermal treatment [30]. Recently, Rafiee et al. found, in the context of wetting, that the van der Waals forces are not disrupted by the graphene sheet as it is extremely thin (ca. 0.3 nm) [14]. Hence, we consider that the edge-on configurations are formed under the influence of the

• . Further after the transfer, the substrates were heated to 400 °C in forming gas for 1 h to remove remaining polymer residues. The structural characteristics of the single-layer graphene were studied using a Horiba XploRA PLUS Raman spectrophotometer with a 532 nm laser and a 50× objective. The molecular

Nickel nanoparticles supported on a covalent triazine framework as electrocatalyst for oxygen evolution reaction and oxygen reduction reactions

• Secil Öztürk,
• Yu-Xuan Xiao,
• Dennis Dietrich,
• Beatriz Giesen,
• Juri Barthel,
• Jie Ying,
• Xiao-Yu Yang and
• Christoph Janiak

Beilstein J. Nanotechnol. 2020, 11, 770–781, doi:10.3762/bjnano.11.62

• nitrogen-containing aromatic polymer frameworks with triazine rings, which exhibit high surface area, porosity, and thermal and chemical stability [21][22]. CTFs are promising materials for applications such as catalysts or catalyst support [23][24][25] and for energy storage and conversion [26][27][28

A novel dry-blending method to reduce the coefficient of thermal expansion of polymer templates for OTFT electrodes

• Xiangdong Ye,
• Bo Tian,
• Yuxuan Guo,
• Fan Fan and
• Anjiang Cai

Beilstein J. Nanotechnol. 2020, 11, 671–677, doi:10.3762/bjnano.11.53

• Telecommunications, Xi’an 710121, China 10.3762/bjnano.11.53 Abstract Among the patterning technologies for organic thin-film transistors (OTFTs), the fabrication of OTFT electrodes using polymer templates has attracted much attention. However, deviations in the electrode alignment occur because the coefficient of

• thermal expansion (CTE) of the polymer template is much higher than the CTE of the dielectric layer. Here, a novel dry-blending method is described in which SiO2 nanoparticles are filled into a grooved silicon template, followed by permeation of polydimethylsiloxane (PDMS) into the SiO2 nanoparticle gaps

• -generation large-area, light-weight, flexible, and stretchable optoelectronic applications [1][2], including flexible displays [3], electronic papers [4], sensors [5], and medical applications [6]. Fabricating high-performance OTFTs usually requires that the electrodes on the polymer template are precisely

Silver-decorated gel-shell nanobeads: physicochemical characterization and evaluation of antibacterial properties

• Marta Bartel,
• Katarzyna Markowska,
• Marcin Strawski,
• Krystyna Wolska and
• Maciej Mazur

Beilstein J. Nanotechnol. 2020, 11, 620–630, doi:10.3762/bjnano.11.49

• layer producing silver nanoparticles but also transforms a fraction of sulfonic groups in the polymer to moieties with sulfur in a lower oxidation state, likely thiols. It is hypothesized that the generated thiol groups are anchoring the nanoparticles in the gel shell of the nanobeads stabilizing the

• ; Staphylococcus sp; Introduction Over the last several years, scientific advances in synthetic polymer materials resulted in a number of applications. With regard to this, special attention has been paid to polymer nanoparticles [1][2]. Polymer nanobeads have been used in various areas including electrochemistry

• [3][4], catalysis [5][6][7] and drug delivery [8][9]. The main advantages of such particles are large surface area and low density. The particles can be further modified to provide new properties to these materials. One modification is the incorporation of metal nanoparticles into the polymer beads

Soybean-derived blue photoluminescent carbon dots

• Shanshan Wang,
• Wei Sun,
• Dong-sheng Yang and
• Fuqian Yang

Beilstein J. Nanotechnol. 2020, 11, 606–619, doi:10.3762/bjnano.11.48

• ] synthesized photoluminescent CDs of 1.5–4.5 nm in diameter from orange juice at 120 °C. Liu et al. [22] produced photoluminescent polymer nanodots of 3–5 nm in diameter by using grass as a precursor at 180 °C, and Zhu et al. [10] synthesized bifunctional blue-emission carbon nanodots with diameters of 13–40

Adsorptive removal of bulky dye molecules from water with mesoporous polyaniline-derived carbon

• Hyung Jun An,
• Jong Min Park,
• Nazmul Abedin Khan and
• Sung Hwa Jhung

Beilstein J. Nanotechnol. 2020, 11, 597–605, doi:10.3762/bjnano.11.47

• ]. Moreover, highly porous carbon materials, especially with high nitrogen content, have been produced from various precursors including organic polymers [29][30][31][32][33] and MOFs [34][35][36][37][38]. Polyaniline (PANI), prepared from aniline, is a useful polymer in various fields because of its facile

Multilayer capsules made of weak polyelectrolytes: a review on the preparation, functionalization and applications in drug delivery

• Varsha Sharma and
• Anandhakumar Sundaramurthy

Beilstein J. Nanotechnol. 2020, 11, 508–532, doi:10.3762/bjnano.11.41

• force [13] using confocal laser scanning microscopy (CLSM), atomic force microscopy (AFM), and reflection interference contrast microscopy (RICM). Fabrication conditions such as the type of polymer (e.g., thicker layers are formed by PEs having lower charge density) [14], concentration of the polymer

• prominent when there are many charged groups present in the system. The use of different charged groups for LbL assembly can impart unique responsiveness to LbL systems as the residual charges in the multilayer films can play an important role in manipulating the polymer/polymer interactions, thus leading

• important step for hollow multilayer capsule preparation is the dissolution and complete removal of its core whose size can vary from nanometers to micrometers. The template should be inert and should not affect the chemical and mechanical properties of the polymer shell. A wide range of organic and

Nanoparticles based on the zwitterionic pillar[5]arene and Ag⁺: synthesis, self-assembly and cytotoxicity in the human lung cancer cell line A549

• Dmitriy N. Shurpik,
• Denis A. Sevastyanov,
• Pavel V. Zelenikhin,
• Pavel L. Padnya,
• Vladimir G. Evtugyn,
• Yuriy N. Osin and
• Ivan I. Stoikov

Beilstein J. Nanotechnol. 2020, 11, 421–431, doi:10.3762/bjnano.11.33

• the stability of supramolecular assemblies to pH changes [22][23]. Another remarkable property of sulfobetaine fragments is the ability to interact with silver ions [24][25][26] and participate in the stabilization of quantum dots [27]. It is worth noting that the use of polymer systems containing

Poly(1-vinylimidazole) polyplexes as novel therapeutic gene carriers for lung cancer therapy

• Gayathri Kandasamy,
• Elena N. Danilovtseva,
• Vadim V. Annenkov and
• Uma Maheswari Krishnan

Beilstein J. Nanotechnol. 2020, 11, 354–369, doi:10.3762/bjnano.11.26

• efficiency of the formed complexes in A549 lung cancer cells. The polyplex formed was found to exhibit 66% complexation efficiency. The complexation was confirmed by gel retardation assays, FTIR and thermal analysis. The blank PVI polymer was not toxic to cells. The polyplex was found to exhibit excellent

• still effective gene carriers. The imidazole ring is involved in many physiological processes and therefore imidazole-containing systems have been investigated for a myriad of biological applications [5]. Poly(vinylimidazole) is a water-soluble polymer, which has been synthesized as poly(1

• -vinylimidazole) and poly(4-vinylimidazole) [6] by using different methods. The imidazole groups can be protonated at acidic pH values conferring cationic character to the polymer. The conformation of PVI chains were found to be altered on protonation that is dependent on the anions present in the system [7

Implementation of data-cube pump–probe KPFM on organic solar cells

• Benjamin Grévin,
• Olivier Bardagot and
• Renaud Demadrille

Beilstein J. Nanotechnol. 2020, 11, 323–337, doi:10.3762/bjnano.11.24

• charges. The latter can eventually reach the collection electrodes of the device. Here, the low-bandgap polymer PTB7 was used as the donor and the fullerene derivative PC71BM as the acceptor. In the BHJ configuration [26], the D and A materials should form two interpenetrated networks phase-segregated at

• same features as the raw data however at a slightly lower noise level. Organic BHJ thin films processing, solar cell fabrication and characterization The PTB7:PC71BM BHJ thin film was deposited on an indium thin oxide (ITO) substrate coated with PEDOT:PSS (a hole-conducting polymer) following the

Understanding nanoparticle flow with a new in vitro experimental and computational approach using hydrogel channels

• Armel Boutchuen,
• Dell Zimmerman,
• Abdollah Arabshahi,
• John Melnyczuk and
• Soubantika Palchoudhury

Beilstein J. Nanotechnol. 2020, 11, 296–309, doi:10.3762/bjnano.11.22

• (PDI: 0.17) and 140 nm (PDI: 0.12), respectively. The iron oxide NP formulations showed similar surface charges (Figure 5c). The low absolute values of zeta potential of the NPs suggested positively charged surfaces stabilized via steric hindrances from the polymer coating. The experimental flow

Phase inversion-based nanoemulsions of medium chain triglyceride as potential drug delivery system for parenteral applications

• Eike Folker Busmann,
• Dailén García Martínez,
• Henrike Lucas and
• Karsten Mäder

Beilstein J. Nanotechnol. 2020, 11, 213–224, doi:10.3762/bjnano.11.16

• solutions of such surfactants increases nonlinearly with the solute concentration due to increasing polymer–solvent hydrogen bonding at low temperatures, which prevents the flow of solvent molecules in the solution and thus affects osmosis. This phenomenon is described by a modified polynomial van’t Hoff

Rational design of block copolymer self-assemblies in photodynamic therapy

• Maxime Demazeau,
• Laure Gibot,
• Anne-Françoise Mingotaud,
• Patricia Vicendo,
• Clément Roux and
• Barbara Lonetti

Beilstein J. Nanotechnol. 2020, 11, 180–212, doi:10.3762/bjnano.11.15

• the importance of intracellular targeting has been addressed. Keywords: intracellular targeting; micelles; photodynamic therapy (PDT); photochemistry; polymer; self-assembly; Review Introduction After Paul Ehrlich, in 1900, had the very first notion of a drug being delivered at will to a specific

• parallel to this development of stealth nanocarriers, polymer chemistry had progressed strongly with the emergence of controlled polymerization. After the discovery of so-called living polymerization (polymerization without any transfer nor any termination reaction) in the 1950’s, the development of

• controlled radical polymerization in the 1990’s provided polymer scientists with a range of chemical tools to synthesize polymers and copolymers exhibiting various architectures, from block and gradient to grafted polymers [7]. Designing new nanocarriers exhibiting an external shell based on PEG and a core

Size effects of graphene nanoplatelets on the properties of high-density polyethylene nanocomposites: morphological, thermal, electrical, and mechanical characterization

• Tuba Evgin,
• Alpaslan Turgut,
• Georges Hamaoui,
• Zdenko Spitalsky,
• Nicolas Horny,
• Matej Micusik,
• Mihai Chirtoc,
• Mehmet Sarikanat and
• Maria Omastova

Beilstein J. Nanotechnol. 2020, 11, 167–179, doi:10.3762/bjnano.11.14

• Eylul University, Engineering Faculty, Mechanical Engineering Department, Tinaztepe Campus, 35397, Buca, Izmir, Turkey GRESPI, Multiscale Thermophysics Lab, Université de Reims Champagne-Ardenne URCA, Reims, France Polymer Institute, SAS, Dúbravská cesta 9, 845 41 Bratislava, Slovak Republic Department

• ’ mechanical properties due to poorer dispersion compared to the others. In addition, the size of the GnPs had no considerable effect on the melting and crystallization properties of the HDPE/GnP nanocomposites. Keywords: electrical properties; graphene nanoplatelets; mechanical properties; polymer matrix

• composites (PMCs); thermal properties; Introduction In recent years, electrically and thermally conductive polymer nanocomposites have attracted considerable attention because of their potential use in many industrial applications, such as aerospace, electronics, packaging, automotives, sensors, batteries

Fabrication of Ag-modified hollow titania spheres via controlled silver diffusion in Ag–TiO₂ core–shell nanostructures

• Bartosz Bartosewicz,
• Malwina Liszewska,
• Bogusław Budner,
• Marta Michalska-Domańska,
• Krzysztof Kopczyński and
• Bartłomiej J. Jankiewicz

Beilstein J. Nanotechnol. 2020, 11, 141–146, doi:10.3762/bjnano.11.12

• carbon template was used in a one-pot synthesis of uniform TiO2–Ag hybrid HSs [16], and of Ag/AgCl modified self-doped TiO2 HSs [17]. Finally, polymer spheres were used as hard-templates in a multistep fabrication of tri-modified TiO2 HSs (Ag–C/N–TiO2) [18], and of silver/TiO2 HSs [19]. Many papers

Molecular architectonics of DNA for functional nanoarchitectures

• Debasis Ghosh,
• Lakshmi P. Datta and
• Thimmaiah Govindaraju

Beilstein J. Nanotechnol. 2020, 11, 124–140, doi:10.3762/bjnano.11.11

• from DNA block copolymer micelles [100]. The block copolymer micelles were synthesized through ring-opening polymerization, followed by the integration of DNA oligonucleotides in a postpolymerization modification process. The DNA acted as a polar head group, while the whole polymer system acted as a

A review of demodulation techniques for multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2020, 11, 76–91, doi:10.3762/bjnano.11.8

• ) tracking bandwidths. The input signal is described by Equation 2, where A1 = 500 mV, A2 = 100 mV, A3 = 50 mV and f1 = 50 kHz, f2 = 150 kHz and f3 = 300 kHz. Higher-harmonic amplitude AFM imaging performed with the fundamental mode of a TAP190G cantilever on a PS/LPDE polymer blend. Images shown are the (a

An investigation on the drag reduction performance of bioinspired pipeline surfaces with transverse microgrooves

• Weili Liu,
• Hongjian Ni,
• Peng Wang and
• Yi Zhou

Beilstein J. Nanotechnol. 2020, 11, 24–40, doi:10.3762/bjnano.11.3

• severely hinders the exploration of oil and gas resources in deep wells [4][5][6]; therefore, it is necessary to put additional effort into reducing the skin friction drag. Conventional hydraulic drag reduction methods include the development of high-performance polymer additives to reduce fluid viscosity

• [7][8][9], the injection of gas to modify the turbulent boundary characteristics [10], and the fabrication of superhydrophobic surfaces to reduce the adhesion [11]. However, the application of polymer additives is not economic and the antidrag performance of additives is also instable under some

• flow drag with the bionic pipeline under the same condition. Governing equations A commercial CFD tool, ANSYS Fluent-18.0, was used to calculate the turbulent flow in the pipe and the concentric annulus. Near-wall turbulence characteristics of a drag-reducing polymer fluid flow in the concentric

The different ways to chitosan/hyaluronic acid nanoparticles: templated vs direct complexation. Influence of particle preparation on morphology, cell uptake and silencing efficiency

• Arianna Gennari,
• Julio M. Rios de la Rosa,
• Erwin Hohn,
• Maria Pelliccia,
• Enrique Lallana,
• Roberto Donno,
• Annalisa Tirella and
• Nicola Tirelli

Beilstein J. Nanotechnol. 2019, 10, 2594–2608, doi:10.3762/bjnano.10.250

• for a hard, uniform sphere, 1.0 for vesicles with thin walls (hollow spheres), close to 1.5 for random polymer coil conformations [23][24]. Fractal dimension (D). When applied to particulates, the fractal geometry analysis is another important morphological indicator. For example, aggregation of

• and HA, producing nanoparticles selectively containing one labelled polymer. Following either chitosan- or HA-associated fluorescence (respectively black and red symbols in Figure 5), we observed qualitatively similar uptake kinetics, which is a sign that the two components are mostly internalized

Fully amino acid-based hydrogel as potential scaffold for cell culturing and drug delivery

• Dávid Juriga,
• Evelin Sipos,
• Orsolya Hegedűs,
• Gábor Varga,
• Miklós Zrínyi,
• Krisztina S. Nagy and
• Angéla Jedlovszky-Hajdú

Beilstein J. Nanotechnol. 2019, 10, 2579–2593, doi:10.3762/bjnano.10.249

• , Nagyvarad square 4, Budapest, Hungary 10.3762/bjnano.10.249 Abstract Polymer hydrogels are ideal scaffolds for both tissue engineering and drug delivery. A great advantage of poly(amino acid)-based hydrogels is their high similarity to natural proteins. However, their expensive and complicated synthesis

• often limits their application. The use of poly(aspartic acid) (PASP) seems an appropriate solution for this problem due to the relatively cheap and simple synthesis of PASP. Using amino acids not only as building blocks in the polymer backbone but also as cross-linkers can improve the biocompatibility

• and the biodegradability of the hydrogel. In this paper, PASP cross-linked with cystamine (CYS) and lysine-methylester (LYS) was introduced as fully amino acid-based polymer hydrogel. Gels were synthesized employing six different ratios of CYS and LYS. The pH dependent swelling degree and the