Surface-enhanced Raman scattering of water in aqueous dispersions of silver nanoparticles

• Paulina Filipczak,
• Krzysztof Hałagan,
• Jacek Ulański and
• Marcin Kozanecki

Beilstein J. Nanotechnol. 2021, 12, 497–506, doi:10.3762/bjnano.12.40

• molecules in aqueous dispersions of AgNPs are presented. The influence of temperature on the enhancement effect is discussed with respect to the supramolecular structure of water. Results and Discussion Characterisation of silver nanoparticles This article presents the SERS effect of water in aqueous

• dispersions of AgNPs. The AgNPs were synthesized according to the protocol proposed by Frank et al. [36]. Two types of nanoparticles were obtained: AgNPs blue and AgNPs yellow, which were labelled according to the colour (compare the UV–vis spectra shown in Figure S1 in Supporting Information File 1). High

• Raman spectra for pure water and aqueous dispersions of silver nanoparticles were performed at room temperature (see Figure 2). Polarised Raman measurements were carried out in x(y,y)z (parallel) and x(y,x)z (perpendicular) configurations. All spectra were normalised to the total integral intensity

ZnO and MXenes as electrode materials for supercapacitor devices

• Ameen Uddin Ammar,
• Ipek Deniz Yildirim,
• Feray Bakan and
• Emre Erdem

Beilstein J. Nanotechnol. 2021, 12, 49–57, doi:10.3762/bjnano.12.4

• [33]. Fan et al. synthesized MXene/holey graphene (HGO) films, to be used as electrode material in supercapacitors, through the filtration of alkalized MXene and HGO dispersions. The prepared material, when used as a composite film electrode for supercapacitors, showed a high volumetric capacitance of

Effect of different silica coatings on the toxicity of upconversion nanoparticles on RAW 264.7 macrophage cells

• Cynthia Kembuan,
• Helena Oliveira and
• Christina Graf

Beilstein J. Nanotechnol. 2021, 12, 35–48, doi:10.3762/bjnano.12.3

• , UCNPs in aqueous dispersions undergo minor disintegration, which also results in the quenching of their luminescence intensity [8][10][18][19][20][21][22][23]. This concentration-dependent effect is especially significant when the dispersions are highly diluted [8][19][22], when the pH value is low [22

• (pore size: 0.2 µm, Rotilab). Nylon filters were used for particles dispersed in cyclohexane and ethanol, whereas regenerated cellulose filters were used for particles dispersed in water or DMEM. Zeta potential measurements of the dispersions in ethanol and water were carried out using capillary zeta

• silica-coated UCNPs and for the UCNP cores was obtained. The dispersions were kept at 37 °C for 24 h, and centrifuged with centrifuge tubes containing membrane filters (Amicon ultracentrifuge, low-binding ultracel membrane, 3000 molecular weight cutoff (MWCO)) for 2 h at 3080g. Aliquots were diluted in

PEG/PEI-functionalized single-walled carbon nanotubes as delivery carriers for doxorubicin: synthesis, characterization, and in vitro evaluation

• Shuoye Yang,
• Zhenwei Wang,
• Yahong Ping,
• Yuying Miao,
• Yongmei Xiao,
• Lingbo Qu,
• Lu Zhang,
• Yuansen Hu and
• Jinshui Wang

Beilstein J. Nanotechnol. 2020, 11, 1728–1741, doi:10.3762/bjnano.11.155

• was obtained by dialysis and vacuum drying successively as above. This difunctionalized CNT carrier was named CNTs-PEG-PEI. Characterization of nanocarriers Different aqueous dispersions of SWCNTs were dispersed onto holey carbon film on copper grids. The sample morphologies were observed by

• (AFM) measurements, different SWCNT dispersions (ethanol/ultrapure water = 1:1) with a concentration of 0.01% were dripped on freshly cleaved mica and observed using an AFM (Dimension Icon, Bruker AXS). Drug loading and encapsulation efficiency An amount of 50 mg of different SWCNT samples were

• . Moreover, their length is much shorter than that of the raw SWCNTs, also being consistent with the TEM observations. The above results prove that the raw SWCNTs were shortened by the acid treatment, together with an improvement of the dispersion state. Thus, highly stable dispersions of individual CNTs can

Cu₂O nanoparticles for the degradation of methyl parathion

• Juan Rizo,
• David Díaz,
• Benito Reyes-Trejo and
• M. Josefina Arellano-Jiménez

Beilstein J. Nanotechnol. 2020, 11, 1546–1555, doi:10.3762/bjnano.11.137

• indicate Miller indices obtained from powder diffraction file (PDF) 74-1230. Color powders for the three different sizes as well as their color in aqueous dispersions with a concentration of 7.5 × 10−4 M. a) HRTEM image of typical Cu2O NP used in degradation of MP. Particle average size in the range of 16

A few-layer graphene/chlorin e6 hybrid nanomaterial and its application in photodynamic therapy against Candida albicans

• Selene Acosta,
• Carlos Moreno-Aguilar,
• Dania Hernández-Sánchez,
• Beatriz Morales-Cruzado,
• Erick Sarmiento-Gomez,
• Carla Bittencourt,
• Luis Octavio Sánchez-Vargas and
• Mildred Quintana

Beilstein J. Nanotechnol. 2020, 11, 1054–1061, doi:10.3762/bjnano.11.90

• power impinging on the sample was between 5 and 10 mW, the spatial resolution was 2 cm−1 and the spot size was ≈1 µm2. The samples were recorded from drops of the dispersions deposited on clean silicon wafers and left to dry under vacuum. The chemical composition of the samples was investigated using X

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

• IOP dispersions in 1% acetic acid using a dynamic light scattering device (ZetaSizer NanoSP, Malvern, United Kingdom). Preparation of chitosan microfibers with IOPs A coagulation bath containing absolute ethanol (VWR, Darmstadt, Germany) was prepared in a polyethylene terephthalate glycol tube (MOCAP

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

• in a glovebox for 12 h. The mass of the nickel precursor was set to yield 0.5 or 1.0 wt % metal nanoparticles in IL, whereas 1.0 wt % CTF was used for all syntheses in IL dispersions. This dispersion was placed in a microwave (CEM Discover) and irradiated with a power of 50 W to 230 °C for 10 min

Exfoliation in a low boiling point solvent and electrochemical applications of MoO₃

• Matangi Sricharan,
• Bikesh Gupta,
• Sreejesh Moolayadukkam and
• H. S. S. Ramakrishna Matte

Beilstein J. Nanotechnol. 2020, 11, 662–670, doi:10.3762/bjnano.11.52

• crucial to exfoliate MoO3 for improved performance in a variety of applications. Liquid-phase exfoliation (LPE) has been shown to be an effective technique for obtaining dispersions of two-dimensional materials. It also offers the advantages of low cost and scalability [2]. The LPE process is initiated

• dimethylformamide are the best solvents [10]. The high boiling point of these dispersions (bp > 150 °C) restrict the usage in flexible devices along with issue that these solvents are also toxic (NFPA 704 health code above 2 [11]). There are reports in literature where MoO3 has been exfoliated in solvents with low

• boiling point, such as isopropyl alcohol (IPA) [5]. Alternative approaches for obtaining MoO3 dispersions in low boiling point solvents have also been reported. For instance, Alsaif et al. have exfoliated MoO3 in mixtures of water and alcohols (methanol, ethanol, IPA) [12]. In these dispersions molybdenum

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

• diffusion and hydrodynamic forces for the flow of these aqueous NP dispersions and additional frictional forces in the NP flow path due to the soft and uneven surface of the hydrogel channels. This size-dependent flow behavior of aqueous NP solutions within soft biomimetic channels is a key finding in terms

• experimental results. A computational analysis was conducted for nanofluid flow through an unbent cylindrical hydrogel channel to further confirm the applicability and accuracy of our experimental results. Two aqueous dispersions of 0.07 mmol PVP/0.005 mmol PEI-coated iron oxide NPs (size: 144 nm) of inlet

• for understanding the mechanisms of NP transport in physiological microenvironments with pHEMA hydrogel channels are the first of its kind, to the best of our knowledge. We discovered that the flow trajectory of aqueous NP dispersions was greatly influenced by the Brownian forces, surrounding fluid

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

• surfaces of the HDPE/GnP nanocomposites with 5.52 vol % GnPs are shown in Figure 1d, Figure 1e, and Figure 1f to compare their structures. All types of GnPs were randomly and homogeneously distributed throughout the HDPE matrix where these layers separated the GnP nanoflakes. Two different dispersions of

Small protein sequences can induce cellular uptake of complex nanohybrids

• Jan-Philip Merkl,
• Malak Safi,
• Christian Schmidtke,
• Fadi Aldeek,
• Johannes Ostermann,
• Tatiana Domitrovic,
• Sebastian Gärtner,
• John E. Johnson,
• Horst Weller and
• Hedi Mattoussi

Beilstein J. Nanotechnol. 2019, 10, 2477–2482, doi:10.3762/bjnano.10.238

• the bound MBP stays functional [8][23][28]. Further details are available in Supporting Information File 1. After confirming the structural integrity and colloidal stability of the nanohybrids, we then proceeded to probe their interactions with HeLa cell cultures. For this, dispersions made of

Coating of upconversion nanoparticles with silica nanoshells of 5–250 nm thickness

• Cynthia Kembuan,
• Maysoon Saleh,
• Bastian Rühle,
• Ute Resch-Genger and
• Christina Graf

Beilstein J. Nanotechnol. 2019, 10, 2410–2421, doi:10.3762/bjnano.10.231

• narrow PDI value of sample C1_5S. The z-average value exceeds the average diameter derived from TEM by (17 ± 5)%. The dispersion has a high colloidal stability due to the highly negative zeta potential of the particles, which is typical for silica dispersions from Stöber-like growth processes containing

• (pore size: 0.2 µm; materials: nylon or polytetrafluoroethylene (PTFE) for particles dispersed in cyclohexane and nylon or regenerated cellulose for particles dispersed in ethanol, Rotilab). Zeta potential measurements of the aqueous dispersions were carried out with a Zetasizer Nano ZS in capillary

• the UCNP samples, 1 mL of the dispersions (c = 5 g/L in cyclohexane for the oleate-coated UCNPs or in ethanol for the silica-coated UCNP) was dried. The dried particles were dissolved in 1 mL of aqua regia for at least 30 min and diluted with at least 5 mL of ultrapure water. The measurements were

Design of a nanostructured mucoadhesive system containing curcumin for buccal application: from physicochemical to biological aspects

• Sabrina Barbosa de Souza Ferreira,
• Gustavo Braga,
• Évelin Lemos Oliveira,
• Jéssica Bassi da Silva,
• Hélen Cássia Rosseto,
• Lidiane Vizioli de Castro Hoshino,
• Mauro Luciano Baesso,
• Wilker Caetano,
• Craig Murdoch,
• Helen Elizabeth Colley and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2019, 10, 2304–2328, doi:10.3762/bjnano.10.222

• in tumor and healthy cell lines. The formulations prepared from solid dispersions stored at 25 °C containing P407, C974P and CUR displayed viscoelastic properties, plastic behavior with rheopexy at body temperature (which provides better retention), and increased mucoadhesive force due to the

BergaCare SmartLipids: commercial lipophilic active concentrates for improved performance of dermal products

• Florence Olechowski,
• Rainer H. Müller and
• Sung Min Pyo

Beilstein J. Nanotechnol. 2019, 10, 2152–2162, doi:10.3762/bjnano.10.208

• particle dispersions during storage and in final products are (1) an unchanged crystalline structure of the particle matrix and (2) the quantitative proof of remaining existence/presence of particles. The created crystalline structure should primarily remain in the unordered state for firm inclusion of

Improved adsorption and degradation performance by S-doping of (001)-TiO₂

• Xiao-Yu Sun,
• Xian Zhang,
• Xiao Sun,
• Ni-Xian Qian,
• Min Wang and
• Yong-Qing Ma

Beilstein J. Nanotechnol. 2019, 10, 2116–2127, doi:10.3762/bjnano.10.206

• distribution calculated using the BJH method. The PL spectra of 2-S0, 2-S0.5, 2-S2, 2-S3 and 2-S5 using an excitation wavelength of λex = 300 nm. ESR spectra of radical adducts trapped by DMPO in 2-S0 (a, e), 2-S2 (b, f), 2-S3 (c, g), and 2-S2 (d, h) dispersions: (a, b, c, d) DMPO–•OH formed in aqueous

• dispersions, (e, f, g, h) DMPO–•O2− formed in methanol dispersion. The unit cell parameters a, c and the c/a value for S-doped (001)-TiO2 at 250 °C. Position of the FTIR absorption peaks and the corresponding vibrational modes. The chemical states (CSs) of Ti, O and S and the corresponding binding energies

Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via fluorous interactions

• Da Shi,
• Justine Wallyn,
• Dinh-Vu Nguyen,
• Francis Perton,
• Delphine Felder-Flesch,
• Sylvie Bégin-Colin,
• Mounir Maaloum and
• Marie Pierre Krafft

Beilstein J. Nanotechnol. 2019, 10, 2103–2115, doi:10.3762/bjnano.10.205

• ), were synthesized and grafted on the surface of iron oxide nanoparticles (IONPs) for microbubble-mediated imaging and therapeutic purposes. The size and stability of the dendronized IONPs (IONP@CnX2n+1OEG8Den) in aqueous dispersions were monitored by dynamic light scattering. The investigation of the

• into the phospholipid shell of the MBs. OEG chains were selected in order to improve the dispersibility of the IONPs in water [27][28]. Dendritic phosphonates are effective anchoring agents due to the covalent PO–metal bonds that stabilize aqueous dispersions of IONPs [27][29]. Such dendronized IONPs

• rapidly onto the interface, as indicated by the instant reduction of the interfacial tension σ by ≈4 mN m−1 (from 72 to 68 ± 0.5 mN m−1, Supporting Information File 1, Figure S3). The concentration of Fe in the IONP dispersions was varied from 10−4 to 10−1 mol L−1. The variations of the interfacial

Preservation of rutin nanosuspensions without the use of preservatives

• Pascal L. Stahr and
• Cornelia M. Keck

Beilstein J. Nanotechnol. 2019, 10, 1902–1913, doi:10.3762/bjnano.10.185

• , bulk suspensions containing 5% (w/w) rutin and 1% (w/w) surfactant were prepared. The pre-dispersions were homogenized with a high-speed stirrer (D-27, Miccra GmbH, Germany) at 24,000 rpm for 5 min in continuous mode and were subsequently subjected to HPH (20 cycles at 1500 bar). During homogenization

Lipid nanostructures for antioxidant delivery: a comparative preformulation study

• Elisabetta Esposito,
• Maddalena Sguizzato,
• Markus Drechsler,
• Paolo Mariani,
• Federica Carducci,
• Claudio Nastruzzi,
• Giuseppe Valacchi and
• Rita Cortesi

Beilstein J. Nanotechnol. 2019, 10, 1789–1801, doi:10.3762/bjnano.10.174

• , the emulsion was subjected to ultrasound homogenization at 6.75 kHz for 15 min (Microson ultrasonic Cell Disruptor-XL Minisonix) and allowed to cool at 25 °C. Lipid nanoparticle dispersions were stored at room temperature. In the case of drug-loaded nanoparticles, TOC (0.4–0.8% w/w with respect to the

• formation during the preparation, which caused irregular and inhomogeneous formulations; thus 2.5% w/w of poloxamer was used. The hot homogenization method followed by ultrasound [39] lead to production of milky and homogeneous dispersions. Immediately after cooling, in most cases, a small amount of

Biocatalytic oligomerization-induced self-assembly of crystalline cellulose oligomers into nanoribbon networks assisted by organic solvents

• Yuuki Hata,
• Yuka Fukaya,
• Toshiki Sawada,
• Masahito Nishiura and
• Takeshi Serizawa

Beilstein J. Nanotechnol. 2019, 10, 1778–1788, doi:10.3762/bjnano.10.173

• , the mixtures after the reaction (0.3 mL) were subjected to pipetting to obtain product dispersions. The resultant particulate products were purified with water/organic solvent mixtures (the organic solvent concentrations were the same as those in the reaction mixtures) by performing at least five

• centrifugation (20,400g)/redispersion cycles to remove more than 99.999% of the soluble fraction of the reaction mixtures. For MALDI–TOF mass spectrometry, the purified product dispersions were stored at 4 °C until use. For the quantification of the insoluble products, a volume of the purified product

• dispersions was dried at 105 °C for 24 h, followed by weighing. For 1H NMR spectroscopy, ATR-FTIR absorption spectroscopy, and XRD measurements, as much as possible of the supernatant after the final centrifugation was removed by pipette, followed by adding water to the products. The resultant product aqueous

Synthesis of nickel/gallium nanoalloys using a dual-source approach in 1-alkyl-3-methylimidazole ionic liquids

• Ilka Simon,
• Julius Hornung,
• Juri Barthel,
• Jörg Thomas,
• Maik Finze,
• Roland A. Fischer and
• Christoph Janiak

Beilstein J. Nanotechnol. 2019, 10, 1754–1767, doi:10.3762/bjnano.10.171

• for a chosen time (30 min, 1 h, 12 h or 24 h) in the dried and desoxygenated IL or PC before microwave decomposition to gain 0.5–1.5 wt % dispersion of the nanoparticles. All precursor dispersions were decomposed at a power of 50 W to a temperature of 230 °C for a chosen time (10 min, 20 min, 30 min

Development of a new hybrid approach combining AFM and SEM for the nanoparticle dimensional metrology

• Loïc Crouzier,
• Alexandra Delvallée,
• Sébastien Ducourtieux,
• Laurent Devoille,
• Guillaume Noircler,
• Christian Ulysse,
• Olivier Taché,
• Elodie Barruet,
• Christophe Tromas and
• Nicolas Feltin

Beilstein J. Nanotechnol. 2019, 10, 1523–1536, doi:10.3762/bjnano.10.150

• likely explain the fact that, as shown in Figure 7, the measurement dispersions are higher for near-spherical nanoparticles with sizes larger than 40 nm. Regarding the 1st mode of the 30R50 population (DSEM = 37.6 nm), the ratio (HAFM/DFmin) is equal to 1.00 ± 0.03, suggesting that these NPs have a

Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

• Giulia Lo Dico,
• Bernd Wicklein,
• Lorenzo Lisuzzo,
• Giuseppe Lazzara,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2019, 10, 1303–1315, doi:10.3762/bjnano.10.129

• , Università degli Studi di Palermo, Viale delle Scienze pad 17, 90128 Palermo, Italy 10.3762/bjnano.10.129 Abstract Based on the unique ability of defibrillated sepiolite (SEP) to form stable and homogeneous colloidal dispersions of diverse types of nanoparticles in aqueous media under ultrasonication

• different properties will determine a functional set of predetermined utility with SEP maintaining stable colloidal dispersions of different nanoparticles and polymers in water. Keywords: bionanocomposites; carbon nanostructures; electrochemical devices; halloysite nanotubes; sepiolite; Introduction In

• obtain homogeneous dispersions within different polymeric matrices [22][23][24]. Therefore, other and more efficient colloidal stabilizers are needed to fully exploit the potential of HNTs. It has been recently observed that fibrous sepiolite clay mineral of rheological grade (see Experimental section

Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction

• Rafael Gomes Morais,
• Natalia Rey-Raap,
• José Luís Figueiredo and
• Manuel Fernando Ribeiro Pereira

Beilstein J. Nanotechnol. 2019, 10, 1089–1102, doi:10.3762/bjnano.10.109

• during the ORR was also measured by using a rotating ring disk electrode (5 mm diameter, 24.9% collection efficiency, Methrom) as a working electrode, which was prepared by depositing a solution of the carbon sample on the disk area. The dispersions were prepared as detailed above and the mass loading

Tailoring the stability/aggregation of one-dimensional TiO₂(B)/titanate nanowires using surfactants

• Atiđa Selmani,
• Johannes Lützenkirchen,
• Kristina Kučanda,
• Dario Dabić,
• Engelbert Redel,
• Ida Delač Marion,
• Damir Kralj,
• Darija Domazet Jurašin and
• Maja Dutour Sikirić

Beilstein J. Nanotechnol. 2019, 10, 1024–1037, doi:10.3762/bjnano.10.103

• application of TNMs has spurred numerous discussions and investigations concerning their behavior, transport and fate in aqueous environments [11][12]. The aggregation behavior, that is, the stability of nanomaterial (NM) dispersions in general, is one of the key factors for their successful application

• NM dispersions can be controlled by applying one of two approaches: (i) mechanical treatment or (ii) chemical and physical modification [15]. Recently, one-dimensional (1D) TNMs have emerged as an exceptional class of NMs. Their geometry offers unique properties that are difficult to achieve with

• surfactants adsorb onto the TNW surface. Moreover, the SCM in principle enables the prediction and optimization of surfactant adsorption on TNW surfaces, thus defining the conditions for stabilization or aggregation. The obtained results point to a simple way of controlling the TNW stability in dispersions