Nanomaterials

Research

14 pages, 3797 KiB

Open AccessArticle

Biodistribution of Poly(alkyl cyanoacrylate) Nanoparticles in Mice and Effect on Tumor Infiltration of Macrophages into a Patient-Derived Breast Cancer Xenograft

by Abhilash D. Pandya, Tore-Geir Iversen, Siver Moestue, Maria T. Grinde, Ýrr Mørch, Sofie Snipstad, Andreas K. O. Åslund, Geir F. Øy, Wanja Kildal, Olav Engebråten, Kirsten Sandvig, Tore Skotland and Gunhild M. Mælandsmo

Nanomaterials 2021, 11(5), 1140; https://doi.org/10.3390/nano11051140 - 28 Apr 2021

Cited by 11 | Viewed by 4178

Abstract

We have investigated the biodistribution and tumor macrophage infiltration after intravenous injection of the poly(alkyl cyanoacrylate) nanoparticles (NPs): PEBCA (poly(2-ethyl-butyl cyanoacrylate), PBCA (poly(n-butyl cyanoacrylate), and POCA (poly(octyl cyanoacrylate), in mice. These NPs are structurally similar, have similar PEGylation, and have previously been shown [...] Read more.

We have investigated the biodistribution and tumor macrophage infiltration after intravenous injection of the poly(alkyl cyanoacrylate) nanoparticles (NPs): PEBCA (poly(2-ethyl-butyl cyanoacrylate), PBCA (poly(n-butyl cyanoacrylate), and POCA (poly(octyl cyanoacrylate), in mice. These NPs are structurally similar, have similar PEGylation, and have previously been shown to give large variations in cellular responses in vitro. The PEBCA NPs had the highest uptake both in the patient-derived breast cancer xenograft MAS98.12 and in lymph nodes, and therefore, they are the most promising of these NPs for delivery of cancer drugs. High-resolution magic angle spinning magnetic resonance (HR MAS MR) spectroscopy did not reveal any differences in the metabolic profiles of tumors following injection of the NPs, but the PEBCA NPs resulted in higher tumor infiltration of the anti-tumorigenic M1 macrophages than obtained with the two other NPs. The PEBCA NPs also increased the ratio of M1/M2 (anti-tumorigenic/pro-tumorigenic) macrophages in the tumors, suggesting that these NPs might be used both as a vehicle for drug delivery and to modulate the immune response in favor of enhanced therapeutic effects. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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12 pages, 3035 KiB

Open AccessArticle

The Improvement of Energy Storage Performance by Sucrose-Derived Carbon Foams via Incorporating Nitrogen Atoms

by Malgorzata Skorupska, Piotr Kamedulski, Jerzy P. Lukaszewicz and Anna Ilnicka

Nanomaterials 2021, 11(3), 760; https://doi.org/10.3390/nano11030760 - 17 Mar 2021

Cited by 35 | Viewed by 3001

Abstract

This paper addresses the problem of improving electrochemical energy storage with electrode materials obtained from common raw ingredients in a facile synthesis. In this study, we present a simple, one-pot route of synthesizing microporous carbon via a very fast reaction of sucrose and [...] Read more.

This paper addresses the problem of improving electrochemical energy storage with electrode materials obtained from common raw ingredients in a facile synthesis. In this study, we present a simple, one-pot route of synthesizing microporous carbon via a very fast reaction of sucrose and graphene (carbon source), chitosan (carbon and nitrogen source), and H₃PO₄. Porous carbons were successfully produced during high temperature carbonization, using nitrogen as a shielding gas. Samples were characterized using X-ray powder diffractometry, elemental analysis, N₂ adsorption-desorption measurements, scanning electron microscopy, and Raman spectroscopy. The developed carbon material possessed a high surface area, up to 1313 m² g⁻¹, with no chemical or physical activators used in the process. The structural parameters of the microporous carbons varied depending on the ratio of reagents and mass composition. Samples were prepared both with and without chitosan. The present synthesis route has the advantages of being a single-step approach and only involving low-cost and environmentally friendly sources of carbon. More importantly, microporous carbon was prepared without any activators and potentially offers great application in supercapacitors. Cyclic voltammetry and constant current charge–discharge tests show that sucrose-based porous carbons show excellent electrochemical performance with a specific capacitance of up to 143 F g⁻¹ at a current density of 1 A g⁻¹ in a 6 M KOH electrolyte. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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9 pages, 24000 KiB

Open AccessArticle

Pulse Electrodeposited Ni-26 at. %Mo—A Crossover from Nanocrystalline to Amorphous

by Jiongxian Li, Yinong Shi and Xiuyan Li

Nanomaterials 2021, 11(3), 681; https://doi.org/10.3390/nano11030681 - 9 Mar 2021

Cited by 4 | Viewed by 2213

Abstract

A Ni-26 at. %Mo alloy with a composite structure of nanocrystalline and amorphous was synthesized by pulse electrodeposition. The composite structure was composed of mixed regions of amorphous and nanograins divided by a nanocrystalline interface network, which significantly suppressed grain coarsening and shear [...] Read more.

A Ni-26 at. %Mo alloy with a composite structure of nanocrystalline and amorphous was synthesized by pulse electrodeposition. The composite structure was composed of mixed regions of amorphous and nanograins divided by a nanocrystalline interface network, which significantly suppressed grain coarsening and shear banding that would otherwise deteriorate mechanical properties of extremely fine nanograined metal. Plastic strain induced significant crystallization accompanied by Mo diffusion from mixed regions to nanograined interfaces. As a result, the Ni-26 at. %Mo alloy exhibited a superior hardness to its nanograined counterparts. The present work demonstrates an example of enhancing mechanical performance with hybrid structures crossover from nanocrystalline to amorphous. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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16 pages, 4013 KiB

Open AccessArticle

6FDA-DAM:DABA Co-Polyimide Mixed Matrix Membranes with GO and ZIF-8 Mixtures for Effective CO₂/CH₄ Separation

by Anand Jain, Mohd Zamidi Ahmad, Audrey Linkès, Violeta Martin-Gil, Roberto Castro-Muñoz, Pavel Izak, Zdeněk Sofer, Werner Hintz and Vlastimil Fila

Nanomaterials 2021, 11(3), 668; https://doi.org/10.3390/nano11030668 - 8 Mar 2021

Cited by 31 | Viewed by 6565

Abstract

This work presents the gas separation evaluation of 6FDA-DAM:DABA (3:1) co-polyimide and its enhanced mixed matrix membranes (MMMs) with graphene oxide (GO) and ZIF-8 (particle size of <40 nm). The 6FDA-copolyimide was obtained through two-stage poly-condensation polymerization, while the ZIF-8 nanoparticles were synthesized [...] Read more.

This work presents the gas separation evaluation of 6FDA-DAM:DABA (3:1) co-polyimide and its enhanced mixed matrix membranes (MMMs) with graphene oxide (GO) and ZIF-8 (particle size of <40 nm). The 6FDA-copolyimide was obtained through two-stage poly-condensation polymerization, while the ZIF-8 nanoparticles were synthesized using the dry and wet method. The MMMs were preliminarily prepared with 1–4 wt.% GO and 5–15 wt.% ZIF-8 filler loading independently. Based on the best performing GO MMM, the study proceeded with making MMMs based on the mixtures of GO and ZIF-8 with a fixed 1 wt.% GO content (related to the polymer matrix) and varied ZIF-8 loadings. All the materials were characterized thoroughly using TGA, FTIR, XRD, and FESEM. The gas separation was measured with 50:50 vol.% CO₂:CH₄ binary mixture at 2 bar feed pressure and 25 °C. The pristine 6FDA-copolyimide showed CO₂ permeability (P_CO2) of 147 Barrer and CO₂/CH₄ selectivity (α_CO2/CH4) of 47.5. At the optimum GO loading (1 wt.%), the P_CO2 and α_CO2/CH4 were improved by 22% and 7%, respectively. A combination of GO (1 wt.%)/ZIF-8 fillers tremendously improves its P_CO2; by 990% for GO/ZIF-8 (5 wt.%) and 1.124% for GO/ZIF-8 (10 wt.%). Regrettably, the MMMs lost their selectivity by 16–55% due to the non-selective filler-polymer interfacial voids. However, the hybrid MMM performances still resided close to the 2019 upper bound and showed good performance stability when tested at different feed pressure conditions. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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9 pages, 2267 KiB

Open AccessArticle

Cetyltrimethylammonium Bromide (CTAB)-Loaded SiO₂–Ag Mesoporous Nanocomposite as an Efficient Antibacterial Agent

by Aiganym Abduraimova, Anara Molkenova, Assem Duisembekova, Tomiris Mulikova, Damira Kanayeva and Timur Sh. Atabaev

Nanomaterials 2021, 11(2), 477; https://doi.org/10.3390/nano11020477 - 13 Feb 2021

Cited by 42 | Viewed by 4498

Abstract

To date, Ag-based nanomaterials have demonstrated a high potential to overcome antibiotic resistance issues. However, bare Ag nanomaterials are prone to agglomeration in the biological environment, which results in a loss of antibacterial activity over time. Furthermore, it is still challenging to collect [...] Read more.

To date, Ag-based nanomaterials have demonstrated a high potential to overcome antibiotic resistance issues. However, bare Ag nanomaterials are prone to agglomeration in the biological environment, which results in a loss of antibacterial activity over time. Furthermore, it is still challenging to collect small-sized Ag nanomaterials right after the synthesis process. In this study, spherical-shaped Ag nanoparticles (NPs) (~6–10 nm) were attached on the surface of cetyltrimethylammonium bromide (CTAB)-loaded mesoporous silica nanoparticles (MSNs) (~100–110 nm). Antibacterial activity tests suggested that the obtained nanocomposite can be used as a highly efficient antibacterial agent against both Gram-negative and Gram-positive bacterial strains. The minimum inhibitory concentration (MIC) recalculated to pure Ag weight in nanocomposite was found to be ~1.84 µg/mL (for Escherichia coli) and ~0.92 µg/mL (for Staphylococcus aureus)—significantly smaller compared to values reported to date. The improved antibacterial activity of the prepared nanocomposite can be attributed to the even distribution of non-aggregated Ag NPs per volume unit and the presence of CTAB in the nanocomposite pores. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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19 pages, 20356 KiB

Open AccessArticle

Experimental Characterization of Viscoelastic Behaviors of Nano-TiO₂/CaCO₃ Modified Asphalt and Asphalt Mixture

by Chunli Wu, Liding Li, Wensheng Wang and Zhengwei Gu

Nanomaterials 2021, 11(1), 106; https://doi.org/10.3390/nano11010106 - 4 Jan 2021

Cited by 29 | Viewed by 3014

Abstract

The purpose of this paper is to promote the application of nano-TiO₂/CaCO₃ in bituminous materials and present an experimental characterization of viscoelastic behaviors of bitumen and bituminous mixture modified by nano-TiO₂/CaCO₃. In this work, a series [...] Read more.

The purpose of this paper is to promote the application of nano-TiO₂/CaCO₃ in bituminous materials and present an experimental characterization of viscoelastic behaviors of bitumen and bituminous mixture modified by nano-TiO₂/CaCO₃. In this work, a series of viscoelastic behavior characterization tests were conducted, including dynamic shear rheometer (DSR) test for bitumen, uniaxial static compression creep test and dynamic modulus test for bituminous mixture. Moreover, various viscoelastic models with clear physical meanings were used to evaluate the influence of nano-TiO₂/CaCO₃ on the macroscopic performance of bitumen and bituminous mixture. The results show that bitumen and its mixtures are time-temperature dependent. The Christensen-Anderson-Marasteanu (CAM) model of frequency sweep based on DSR test indicated that adding nano-TiO₂/CaCO₃ can effectively capture the sensitivity of temperature. In addition, the incorporation of nano-TiO₂/CaCO₃ in bituminous mixture can significantly enhance the high-temperature anti-rutting, and slightly improve the low-temperature anti-cracking as well. At the same time, the modified Burgers model can accurately describe the viscoelastic behavior of bituminous mixtures in the first two creep stages, reflecting the consolidation effect of bituminous mixture. Also, the generalized Sigmoidal model can accurately grasp the characteristics of the relationship between dynamic modulus and reduced frequency and achieve good prediction effects in a wider frequency range. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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11 pages, 2768 KiB

Open AccessArticle

Rationally Designed CdS-Based Ternary Heterojunctions: A Case of 1T-MoS₂ in CdS/TiO₂ Photocatalyst

by Wenqian Chen, Shaomei Zhang, Ganyu Wang, Gang Huang, Zhichong Yu, Yirui Li and Liang Tang

Nanomaterials 2021, 11(1), 38; https://doi.org/10.3390/nano11010038 - 25 Dec 2020

Cited by 5 | Viewed by 2412

Abstract

As promising heterojunction photocatalysts, the binary CdS-based heterojunctions were investigated extensively. In most of the reported CdS-based heterojunctions, however, electrons come from the semiconductor with wide band gap (e.g., TiO₂) would limit the visible-light absorption of CdS and hence lower the [...] Read more.

As promising heterojunction photocatalysts, the binary CdS-based heterojunctions were investigated extensively. In most of the reported CdS-based heterojunctions, however, electrons come from the semiconductor with wide band gap (e.g., TiO₂) would limit the visible-light absorption of CdS and hence lower the performance. In this work, we introduced 1T-MoS₂ to form a novel ternary heterojunction, namely CdS/1T-MoS₂/TiO₂, in which 1T-MoS₂ has more positive conduction band than CdS and TiO₂. The hydrogen evolution rate of CdS/1T-MoS₂/TiO₂ reaches 3.15 mmol g⁻¹ h⁻¹, which is approximately 12 and 35 times higher than that of pure CdS and CdS/TiO₂ binary heterojunction under the same conditions, respectively. This performance enhancement could be attributed to the presence of 1T-MoS₂ and a plausible mechanism is proposed based on photoelectrochemical characterizations. Our results illustrate that the performance of CdS-based heterojunctions for solar hydrogen evolution can be greatly improved by appropriate materials selection. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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12 pages, 3648 KiB

Open AccessArticle

Enhanced Mechanical Properties of Multiscale Carbon Fiber/Epoxy Unidirectional Composites with Different Dimensional Carbon Nanofillers

by Yu Liu, Dong-Dong Zhang, Guang-Yuan Cui, Rui-Ying Luo and Dong-Lin Zhao

Nanomaterials 2020, 10(9), 1670; https://doi.org/10.3390/nano10091670 - 26 Aug 2020

Cited by 5 | Viewed by 2123

Abstract

Ammonia modified graphene-carbon nanotubes/continuous carbon fiber reinforced epoxy unidirectional multiscale composites (AMGNS-MWCNT/CFEP) were prepared by adding ammonia modified graphene and carbon nanotubes to an epoxy matrix to reduce agglomeration of carbon nanofillers in the epoxy matrix and improve composites properties. Fourier transform infrared [...] Read more.

Ammonia modified graphene-carbon nanotubes/continuous carbon fiber reinforced epoxy unidirectional multiscale composites (AMGNS-MWCNT/CFEP) were prepared by adding ammonia modified graphene and carbon nanotubes to an epoxy matrix to reduce agglomeration of carbon nanofillers in the epoxy matrix and improve composites properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and universal testing machines were used to characterize the properties of carbon nanofillers, AMGNS-MWCNT/epoxy nanocomposites, and AMGNS-MWCNT/CFEP unidirectional composites. When the AMGNS-MWCNT content was 1.0 wt%, flexural strength, the flexural modulus and interlaminar shear strength of AMGNS-MWCNT/CFEP unidirectional composites reached the maximum value of 1520.3 MPa, 138.88 GPa, and 87.80 MPa, respectively, which were 12.5%, 9.42%, and 10.1% higher than that of carbon fiber reinforced epoxy unidirectional composites (CFEP). The synergistic mechanism of two carbon nanofillers in the matrix is discussed. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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11 pages, 1488 KiB

Open AccessArticle

Trace Cd²⁺ Ions Detection on the Flower-Like Ag@CuO Substrate

by Mingming Cheng, Chenyan Li, Weijun Li and Yingkai Liu

Nanomaterials 2020, 10(9), 1664; https://doi.org/10.3390/nano10091664 - 25 Aug 2020

Cited by 15 | Viewed by 2597

Abstract

CuO flower-like material (FM) was prepared via the facile hydrothermal method, and Ag nanoparticles were deposited on the CuO FM to obtain Ag@CuO composite. Rhodamine 6G (R6G) was used as the probe molecule on Ag@CuO FM substrate to study surface enhanced Raman scattering [...] Read more.

CuO flower-like material (FM) was prepared via the facile hydrothermal method, and Ag nanoparticles were deposited on the CuO FM to obtain Ag@CuO composite. Rhodamine 6G (R6G) was used as the probe molecule on Ag@CuO FM substrate to study surface enhanced Raman scattering (SERS). It is discovered that it exhibited an excellent SERS performance with limit of detection of 3.58 × 10⁻¹⁶ M and enhancement factor (EF) of 3.99 × 10¹⁰. More importantly, we used it as a SERS substrate to detect cadmium ions and found that its limit of detection (LOD) reaches up to 2.6 × 10⁻⁸ M, which is lower than the highest allowable Cd²⁺ concentration in drinking water set by the World Health Organization (WHO) and Environmental Protection Agency (EPA). Therefore, the proposed composite can be applicable to the detection of Cd²⁺ in drinking water and in soil. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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21 pages, 14597 KiB

Open AccessArticle

Spectroscopic Properties of Si-nc in SiO_x Films Using HFCVD

by Zaira Jocelyn Hernández Simón, Jose Alberto Luna López, Alvaro David Hernández de la Luz, Sergio Alfonso Pérez García, Alfredo Benítez Lara, Godofredo García Salgado, Jesus Carrillo López, Gabriel Omar Mendoza Conde and Hayde Patricia Martínez Hernández

Nanomaterials 2020, 10(7), 1415; https://doi.org/10.3390/nano10071415 - 20 Jul 2020

Cited by 13 | Viewed by 3099

Abstract

In the present work, non-stoichiometric silicon oxide films (SiO_x) deposited using a hot filament chemical vapor deposition technique at short time and simple parameters of depositions are reported. This is motivated by the numerous potential applications of SiO_x films in [...] Read more.

In the present work, non-stoichiometric silicon oxide films (SiO_x) deposited using a hot filament chemical vapor deposition technique at short time and simple parameters of depositions are reported. This is motivated by the numerous potential applications of SiO_x films in areas such as optoelectronics. SiO_x films were characterized with different spectroscopic techniques. The deposited films have interesting characteristics such as the presence of silicon nanoclusters without applying thermal annealing, in addition to a strong photoluminescence after applying thermal annealing in the vicinity of 1.5 eV, which may be attributed to the presence of small, oxidized silicon grains (less than 2 nm) or silicon nanocrystals (Si-nc). An interesting correlation was found between oxygen content, the presence of hydrogen, and the formation of defects in the material, with parameters such as the band gap and the Urbach energies. This correlation is interesting in the development of band gap engineering for this material for applications in photonic devices. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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13 pages, 5305 KiB

Open AccessArticle

Anisotropic Nanocellulose Aerogel Loaded with Modified UiO-66 as Efficient Adsorbent for Heavy Metal Ions Removal

by Jiajia Li, Sicong Tan and Zhaoyang Xu

Nanomaterials 2020, 10(6), 1114; https://doi.org/10.3390/nano10061114 - 5 Jun 2020

Cited by 54 | Viewed by 4733

Abstract

Currently, the preparation of outstanding adsorbents has attracted public concern in environmentally friendly and sustainable pollutant redress. Herein, we report a directional freeze-drying method to prepare a strong and reusable adsorbent by introducing metal-organic framework which modified by ethylene diamine tetraacetic acid (named [...] Read more.

Currently, the preparation of outstanding adsorbents has attracted public concern in environmentally friendly and sustainable pollutant redress. Herein, we report a directional freeze-drying method to prepare a strong and reusable adsorbent by introducing metal-organic framework which modified by ethylene diamine tetraacetic acid (named UiO-66-EDTA) into cellulose nanofiber (CNF) aerogel. Compared to traditional aerogels, the fabricated adsorbent showed a good flexibility and reusability by forming a homogeneous three-dimensional structure. By controlling the concentration of a crosslinkable carboxymethyl cellulose (CMC) solution, we produced aerogels with different pore structures and fibrillar, columnar, and lamellar morphologies. The obtained UiO-66-EDTA/CNF/CMC aerogel (U_-EDTACCA) showed an excellent adsorption performance for a total of nine types of heavy metal ions, as the removal efficiency could reach 91%. Moreover, the aerogels could retain 88% of their original shape after five cycles. The aerogel may be an appropriate material for the adsorption of heavy metal ions. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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20 pages, 1674 KiB

Open AccessArticle

Study of Physico-Chemical Changes of CdTe QDs after Their Exposure to Environmental Conditions

by Bozena Hosnedlova, Michaela Vsetickova, Martina Stankova, Dagmar Uhlirova, Branislav Ruttkay-Nedecky, Augustine Ofomaja, Carlos Fernandez, Marta Kepinska, Mojmir Baron, Bach Duong Ngoc, Hoai Viet Nguyen, Ha Pham Thi Thu, Jiri Sochor and Rene Kizek

Nanomaterials 2020, 10(5), 865; https://doi.org/10.3390/nano10050865 - 30 Apr 2020

Cited by 11 | Viewed by 3319

Abstract

The irradiance of ultraviolet (UV) radiation is a physical parameter that significantly influences biological molecules by affecting their molecular structure. The influence of UV radiation on nanoparticles has not been investigated much. In this work, the ability of cadmium telluride quantum dots (CdTe [...] Read more.

The irradiance of ultraviolet (UV) radiation is a physical parameter that significantly influences biological molecules by affecting their molecular structure. The influence of UV radiation on nanoparticles has not been investigated much. In this work, the ability of cadmium telluride quantum dots (CdTe QDs) to respond to natural UV radiation was examined. The average size of the yellow QDs was 4 nm, and the sizes of green, red and orange QDs were 2 nm. Quantum yield of green CdTe QDs-MSA (mercaptosuccinic acid)-A, yellow CdTe QDs-MSA-B, orange CdTe QDs-MSA-C and red CdTe QDs-MSA-D were 23.0%, 16.0%, 18.0% and 7.0%, respectively. Green, yellow, orange and red CdTe QDs were replaced every day and exposed to daily UV radiation for 12 h for seven consecutive days in summer with UV index signal integration ranging from 1894 to 2970. The rising dose of UV radiation led to the release of cadmium ions and the change in the size of individual QDs. The shifts were evident in absorption signals (shifts of the absorbance maxima of individual CdTe QDs-MSA were in the range of 6–79 nm), sulfhydryl (SH)-group signals (after UV exposure, the largest changes in the differential signal of the SH groups were observed in the orange, green, and yellow QDs, while in red QDs, there were almost no changes), fluorescence, and electrochemical signals. Yellow, orange and green QDs showed a stronger response to UV radiation than red ones. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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11 pages, 2054 KiB

Open AccessArticle

Stretchable and High-performance Sensor films Based on Nanocomposite of Polypyrrole/SWCNT/Silver Nanowire

by Bu-Yeon Hwang, Wen Xuan Du, Hee-Jae Lee, Sungmin Kang, Masaki Takada and Jin-Yeol Kim

Nanomaterials 2020, 10(4), 696; https://doi.org/10.3390/nano10040696 - 7 Apr 2020

Cited by 17 | Viewed by 3308

Abstract

We report the fabrication of stretchable sensor films (SSF) using a composite of functionalized polypyrrole- single-walled carbon nanotube (SWCNT)-silver nanowire hybrid networks embedded into a cross-linked polydimethylsiloxane elastomer. The SSF exhibited low resistivity of 30 Ω/sq and an outstanding mechanical elasticity of up [...] Read more.

We report the fabrication of stretchable sensor films (SSF) using a composite of functionalized polypyrrole- single-walled carbon nanotube (SWCNT)-silver nanowire hybrid networks embedded into a cross-linked polydimethylsiloxane elastomer. The SSF exhibited low resistivity of 30 Ω/sq and an outstanding mechanical elasticity of up to 25% (no visible change in the sheet resistance after 100 cycle at stretching-release test of 25%). These SSFs were responsive to 1 ppm ammonia gas even at a low temperature of 40 °C with 20% relative humidity and also maintained reproducibility and reversibility when repeatedly exposed to ammonia gas more than 100 times. In addition, it was confirmed that the sensor film was hardly affected even at a relative humidity range of 20% to 80%. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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11 pages, 2829 KiB

Open AccessCommunication

Facile Production of a Fenton-Like Photocatalyst by Two-Step Calcination with a Broad pH Adaptability

by Siyang Ji, Yanling Yang, Xing Li, Hang Liu and Zhiwei Zhou

Nanomaterials 2020, 10(4), 676; https://doi.org/10.3390/nano10040676 - 3 Apr 2020

Cited by 8 | Viewed by 2593

Abstract

A novel heterogeneous Fenton-like photocatalyst, Fe-doped graphitic carbon nitride (Fe-g-C₃N₄), was produced by facile two-step calcination method. This Fe–g–C₃N₄ catalyzed rhodamine B degradation in the presence of H₂O₂ accompanied with visible light irradiation. [...] Read more.

A novel heterogeneous Fenton-like photocatalyst, Fe-doped graphitic carbon nitride (Fe-g-C₃N₄), was produced by facile two-step calcination method. This Fe–g–C₃N₄ catalyzed rhodamine B degradation in the presence of H₂O₂ accompanied with visible light irradiation. transmission electron microscopy(TEM), x-ray diffraction (XRD), FT-IR, x-ray photoelectron spectroscopy (XPS), and photoluminescence fluorescent spectrometer (PL) characterization analysis methods were adopted to evaluate the physicochemical property of samples. It can be observed that the Fe-g-C₃N₄ exhibited excellent photocatalytic Fenton-like activity at a wide pH range of 3–9, with rhodamine B(RhB) degradation efficiency up to 95.5% after irradiation for 45 min in the presence of 1.0 mM H₂O₂. Its high activity was ascribed to the formation of Fe–N ligands in the triazine rings that accelerated electron movement driving the Fe(III)/Fe(II) redox cycle, and inhibited photo-generated electron hole re-combinations for continuous generation of reactive oxygen species by reactions between Fe(II) and H₂O₂. The main active oxygen species were hydroxyl radicals, followed by superoxide radicals and hole electrons. This produced catalyst of Fe–g–C₃N₄ shows excellent reusability and stability, and can be a promising candidate for decontamination of wastewater. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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11 pages, 1989 KiB

Open AccessArticle

Enhanced OER Performances of Au@NiCo₂S₄ Core-Shell Heterostructure

by Yuepeng Lv, Sibin Duan, Yuchen Zhu, Peng Yin and Rongming Wang

Nanomaterials 2020, 10(4), 611; https://doi.org/10.3390/nano10040611 - 27 Mar 2020

Cited by 21 | Viewed by 4159

Abstract

Transition metal sulfides have attracted a lot of attention as potential oxygen evolution reaction (OER) catalysts. Bimetallic sulfide possesses superior physicochemical properties due to the synergistic effect between bimetallic cations. By introducing a metal-semiconductor interface, the physicochemical properties of transition metal sulfide can [...] Read more.

Transition metal sulfides have attracted a lot of attention as potential oxygen evolution reaction (OER) catalysts. Bimetallic sulfide possesses superior physicochemical properties due to the synergistic effect between bimetallic cations. By introducing a metal-semiconductor interface, the physicochemical properties of transition metal sulfide can be further improved. Using the solvothermal method, Au@NiCo₂S₄ core-shell heterostructure nanoparticles (NPs) and bare NiCo₂S₄ NPs were prepared. The measurement of the OER catalytic performance showed that the catalytic activity of Au@NiCo₂S₄ core-shell heterostructure was enhanced compared to bare NiCo₂S₄ NPs. At the current density of 10 mA cm⁻², the overpotential of Au@NiCo₂S₄ (299 mV) is lower than that of bare NiCo₂S₄ (312 mV). The Tafel slope of Au@NiCo₂S₄ (44.5 mV dec⁻¹) was reduced compared to that of bare NiCo₂S₄ (49.1 mV dec⁻¹), indicating its faster reaction kinetics. Detailed analysis of its electronic structure, chemical state, and electrochemical impedance indicates that the enhanced OER catalytic performances of bare Au@NiCo₂S₄ core-shell NPs were a result of its increased proportion of high-valance Ni/Co cations, and its increased electronic conductivity. This work provides a feasible method to improve OER catalytic performance by constructing a metal-semiconductor core-shell heterostructure. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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16 pages, 3914 KiB

Open AccessArticle

Controlled Synthesis of Au Nanocrystals-Metal Selenide Hybrid Nanostructures toward Plasmon-Enhanced Photoelectrochemical Energy Conversion

by Ling Tang, Shan Liang, Jian-Bo Li, Dou Zhang, Wen-Bo Chen, Zhong-Jian Yang, Si Xiao and Qu-Quan Wang

Nanomaterials 2020, 10(3), 564; https://doi.org/10.3390/nano10030564 - 20 Mar 2020

Cited by 8 | Viewed by 3406

Abstract

A simple method for the controllable synthesis of Au nanocrystals–metal selenide hybrid nanostructures via amino acid guiding strategy is proposed. The results show that the symmetric overgrowth mode of PbSe shells on Au nanorods can be precisely manipulated by only adjusting the initial [...] Read more.

A simple method for the controllable synthesis of Au nanocrystals–metal selenide hybrid nanostructures via amino acid guiding strategy is proposed. The results show that the symmetric overgrowth mode of PbSe shells on Au nanorods can be precisely manipulated by only adjusting the initial concentration of Pb²⁺. The shape of Au–PbSe hybrids can evolve from dumbbell-like to yolk-shell. Interestingly, the plasmonic absorption enhancement could be tuned by the symmetry of these hybrid nanostructures. This provides an effective pathway for maneuvering plasmon-induced energy transfer in metal–semiconductor hybrids. In addition, the photoactivities of Au–PbSe nanorods sensitized TiO₂ electrodes have been further evaluated. Owing to the synergism between effective plasmonic enhancement effect and efficient interfacial charge transfer in these hybrid nanostructures, the Au–PbSe yolk-shell nanorods exhibit an outstanding photocurrent activity. Their photocurrent density is 4.38 times larger than that of Au–PbSe dumbbell-like nanorods under light irradiation at λ > 600 nm. As a versatile method, the proposed strategy can also be employed to synthesize other metal–selenide hybrid nanostructures (such as Au–CdSe, Au–Bi₂Se₃ and Au–CuSe). Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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13 pages, 2937 KiB

Open AccessArticle

Core–Shell Structured Phenolic Polymer@TiO₂ Nanosphere with Enhanced Visible-Light Photocatalytic Efficiency

by Xiankui Xu, Lei Zhang, Shihua Zhang, Yanpeng Wang, Baoying Liu and Yanrong Ren

Nanomaterials 2020, 10(3), 467; https://doi.org/10.3390/nano10030467 - 5 Mar 2020

Cited by 7 | Viewed by 3807

Abstract

Core–shell structured TiO₂ is a promising solution to promote the photocatalytic effectiveness in visible light. Compared to metal or semiconductor materials, polymers are rarely used as the core materials for fabricating core–shell TiO₂ materials. A novel core–shell structured polymer@TiO₂ was [...] Read more.

Core–shell structured TiO₂ is a promising solution to promote the photocatalytic effectiveness in visible light. Compared to metal or semiconductor materials, polymers are rarely used as the core materials for fabricating core–shell TiO₂ materials. A novel core–shell structured polymer@TiO₂ was developed by using phenolic polymer (PP) colloid nanoparticles as the core material. The PP nanoparticles were synthesized by an enzyme-catalyzed polymerization in water. A subsequent sol–gel and hydrothermal reaction was utilized to cover the TiO₂ shell on the surfaces of PP particles. The thickness of the TiO₂ shell was controlled by the amount of TiO₂ precursor. The covalent connection between PP and TiO₂ was established after the hydrothermal reaction. The core–shell structure allowed the absorption spectra of PP@TiO₂ to extend to the visible-light region. Under visible-light irradiation, the core–shell nanosphere displayed enhanced photocatalytic efficiency for rhodamine B degradation and good recycle stability. The interfacial C–O–Ti bonds and the π-conjugated structures in the PP@TiO₂ nanosphere played a key role in the quick transfer of the excited electrons between PP and TiO₂, which greatly improved the photocatalytic efficiency in visible light. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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12 pages, 3706 KiB

Open AccessArticle

Study on the Mechanism of Nano-SiO₂ for Improving the Properties of Cement-Based Soil Stabilizer

by Xingchen Zhang, Jianen Gao, Henghui Fan, Xinghua Li, Zhe Gao, Li Xue and Shengli Sun

Nanomaterials 2020, 10(3), 405; https://doi.org/10.3390/nano10030405 - 25 Feb 2020

Cited by 13 | Viewed by 2818

Abstract

A new nano-soil stabilizer (N-MBER, Nanometer Material Becoming Earth into Rock) material was developed in this research by using the high activity and ultrafine properties of nano-SiO₂ (NS), which were able to improve the properties of cement-based soil stabilizer and had broad [...] Read more.

A new nano-soil stabilizer (N-MBER, Nanometer Material Becoming Earth into Rock) material was developed in this research by using the high activity and ultrafine properties of nano-SiO₂ (NS), which were able to improve the properties of cement-based soil stabilizer and had broad application prospects. The results showed that (1) the strength of N-MBER obeyed a compound function relation with curing period and additive amount of NS. The relationship between strength and curing period obeyed an exponential function when the additive amount was constant. The strength and additive amount were a power function when the curing period was fixed. The compressive strength of N-MBER increased by more than 15% compared with MBER at day 28 of the curing period, and 50% compared with grade 32.5 cement. (2) The pozzolanic catalytic activity of NS significantly increased the amount of calcium silicate hydrate gel (C–S–H) in the N-MBER colloid. NS was also able to make the distribution of the network structure of colloidal space more uniform and improved the fractal dimension of particles by 0.05. The above results provide theoretical data for exploring the mechanism of soil stabilizer strength growth and for promoting the application of solid waste utilization. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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22 pages, 3632 KiB

Open AccessArticle

Graphene Oxide–Silver Nanoparticle Nanohybrids: Synthesis, Characterization, and Antimicrobial Properties

by Mónica Cobos, Iker De-La-Pinta, Guillermo Quindós, M. Jesús Fernández and M. Dolores Fernández

Nanomaterials 2020, 10(2), 376; https://doi.org/10.3390/nano10020376 - 21 Feb 2020

Cited by 145 | Viewed by 9498

Abstract

Drug resistance of pathogenic microorganisms has become a global public health problem, which has prompted the development of new materials with antimicrobial properties. In this context, antimicrobial nanohybrids are an alternative due to their synergistic properties. In this study, we used an environmentally [...] Read more.

Drug resistance of pathogenic microorganisms has become a global public health problem, which has prompted the development of new materials with antimicrobial properties. In this context, antimicrobial nanohybrids are an alternative due to their synergistic properties. In this study, we used an environmentally friendly one-step approach to synthesize graphene oxide (GO) decorated with silver nanoparticles (GO–AgNPs). By this process, spherical AgNPs of average size less than 4 nm homogeneously distributed on the surface of the partially reduced GO can be generated in the absence of any stabilizing agent, only with ascorbic acid (L-AA) as a reducing agent and AgNO₃ as a metal precursor. The size of the AgNPs can be controlled by the AgNO₃ concentration and temperature. Smaller AgNPs are obtained at lower concentrations of the silver precursor and lower temperatures. The antimicrobial properties of nanohybrids against Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa, Gram-positive Staphylococcus aureus, and the yeast Candida albicans were found to be concentration- and time-dependent. C. albicans and S. aureus showed the highest susceptibility to GO–AgNPs. These nanohybrids can be used as nanofillers in polymer nanocomposites to develop materials with antimicrobial activity for applications in different areas, and another potential application could be cancer therapeutic agents. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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17 pages, 5241 KiB

Open AccessArticle

Surface-Dependent Osteoblasts Response to TiO₂ Nanotubes of Different Crystallinity

by Yuliya Y. Khrunyk, Sergey V. Belikov, Mikhail V. Tsurkan, Ivan V. Vyalykh, Alexandr Y. Markaryan, Maxim S. Karabanalov, Artemii A. Popov and Marcin Wysokowski

Nanomaterials 2020, 10(2), 320; https://doi.org/10.3390/nano10020320 - 13 Feb 2020

Cited by 32 | Viewed by 4253

Abstract

One of the major challenges of implantology is to design nanoscale modifications of titanium implant surfaces inducing osseointegration. The aim of this study was to investigate the behavior of rat osteoblasts cultured on anodized TiO₂ nanotubes of different crystallinity (amorphous and anatase [...] Read more.

One of the major challenges of implantology is to design nanoscale modifications of titanium implant surfaces inducing osseointegration. The aim of this study was to investigate the behavior of rat osteoblasts cultured on anodized TiO₂ nanotubes of different crystallinity (amorphous and anatase phase) up to 24 days. TiO₂ nanotubes were fabricated on VT1–0 titanium foil via a two-step anodization at 20 V using NH₄F as an electrolyte. Anatase-phase samples were prepared by heat treatment at 500 °C for 1 h. VT1–0 samples with flat surfaces were used as controls. Primary rat osteoblasts were seeded over experimental surfaces for several incubation times. Scanning electron microscopy (SEM) was used to analyze tested surfaces and cell morphology. Cell adhesion and proliferation were investigated by cell counting. Osteogenic differentiation of cells was evaluated by qPCR of runt-related transcription factor 2 (RUNX2), osteopontin (OPN), integrin binding sialoprotein (IBSP), alkaline phosphatase (ALP) and osteocalcin (OCN). Cell adhesion and proliferation, cell morphology and the expression of osteogenic markers were affected by TiO₂ nanotube layered substrates of amorphous and anatase crystallinity. In comparison with flat titanium, along with increased cell adhesion and cell growth a large portion of osteoblasts grown on the both nanostructured surfaces exhibited an osteocyte-like morphology as early as 48 h of culture. Moreover, the expression of all tested osteogenic markers in cells cultured on amorphous and anatase TiO₂ nanotubes was upregulated at least at one of the analyzed time points. To summarize, we demonstrated that amorphous and anodized TiO₂ layered substrates are highly biocompatible with rat osteoblasts and that the surface modification with about 1500 nm length nanotubes of 35 ± 4 (amorphous phase) and 41 ± 8 nm (anatase phase) in diameter is sufficient to induce their osteogenic differentiation. Such results are significant to the engineering of coating strategies for orthopedic implants aimed to establish a more efficient bone to implant contact and enhance bone repair. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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13 pages, 3296 KiB

Open AccessArticle

Dual-Functionalized Pesticide Nanocapsule Delivery System with Improved Spreading Behavior and Enhanced Bioactivity

by Jianxia Cui, Changjiao Sun, Anqi Wang, Yan Wang, Huaxin Zhu, Yue Shen, Ningjun Li, Xiang Zhao, Bo Cui, Chong Wang, Fei Gao, Zhanghua Zeng and Haixin Cui

Nanomaterials 2020, 10(2), 220; https://doi.org/10.3390/nano10020220 - 27 Jan 2020

Cited by 25 | Viewed by 4284

Abstract

The prevention and control of pests and diseases are becoming increasingly difficult owing to extensive pesticide resistance. The synergistic use of pesticides for disease control is an effective way of slowing pesticide resistance, reducing the number of pesticide applications, and protecting the environment. [...] Read more.

The prevention and control of pests and diseases are becoming increasingly difficult owing to extensive pesticide resistance. The synergistic use of pesticides for disease control is an effective way of slowing pesticide resistance, reducing the number of pesticide applications, and protecting the environment. In this study, a dual-functionalized pesticide nanocapsule delivery system loaded with two active ingredients (AIs)—validamycin and thifluzamide—was developed to prevent and control rice sheath blight; the nanocapsule system was based on a water–oil–water double emulsion method combined with high-pressure homogenization technology. Our results showed that the dual-functionalized pesticide nanocapsules were monodisperse spheres with a mean particle size of ~260 nm and had good storage stability. Compared with commercial formulations, the dual-functionalized pesticide nanocapsules exhibited good foliar spread owing to their small size, which is beneficial for reducing the loss of pesticides on the leaves. The 50% median effect concentration and synergistic ratio against Rhizoctonia solani of the dual-functionalized pesticide nanocapsules and commercial formulation were 0.0082 and 0.0350 μg/mL, and 2.088 and 0.917, respectively. These findings indicate that the bioactivity of the dual-functionalized system was significantly better than that of the commercial formulations and that the dual-functionalized system demonstrated a clear synergistic effect between the two AIs. The system presented here is simple, fast, and capable of dual-pesticide loading with significant synergistic effects. Our findings could help to facilitate the improvement of pesticides efficiency and the slowing of pesticide resistance. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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16 pages, 10249 KiB

Open AccessArticle

Sensitive Voltammetric Sensor for Tryptophan Detection by Using Polyvinylpyrrolidone Functionalized Graphene/GCE

by Quanguo He, Jun Liu, Jinxia Feng, Yiyong Wu, Yaling Tian, Guangli Li and Dongchu Chen

Nanomaterials 2020, 10(1), 125; https://doi.org/10.3390/nano10010125 - 9 Jan 2020

Cited by 46 | Viewed by 3773

Abstract

In this paper, an electrochemical method for the measurement of tryptophan (Trp) was developed based on a glassy carbon electrode modified with polyvinylpyrrolidonefunctionalized graphene (PVP-GR)/glassy carbon electrode (GCE). In 0.1 M phosphate buffer solution (PBS, pH = 2.2), compared with bare GCE, PVP/GCE, [...] Read more.

In this paper, an electrochemical method for the measurement of tryptophan (Trp) was developed based on a glassy carbon electrode modified with polyvinylpyrrolidonefunctionalized graphene (PVP-GR)/glassy carbon electrode (GCE). In 0.1 M phosphate buffer solution (PBS, pH = 2.2), compared with bare GCE, PVP/GCE, and GR/GCE, the oxidation peak current of Trp increased dramatically at PVP-GR/GCE. The oxidation mechanism of Trp on the PVP-GR/GCE was discussed and the experimental conditions were optimized. Under the best experimental conditions, the oxidation peak current of Trp was proportional to its concentration in the range of 0.06 µM–10.0 µM and 10.0–100.0 µM, and the limit of detection (LOD) was 0.01 µM (S/N = 3). The target modified electrode with excellent repeatability, stability and selectivity, was successfully applied to detectTrp in drugs and biological samples. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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14 pages, 2561 KiB

Open AccessArticle

Silica-Coated Magnetic Iron Oxide Nanoparticles Grafted onto Graphene Oxide for Protein Isolation

by Xuan-Hung Pham, Eunil Hahm, Hyung-Mo Kim, Byung Sung Son, Ahla Jo, Jaehyun An, Tuong An Tran Thi, Dinh Quan Nguyen and Bong-Hyun Jun

Nanomaterials 2020, 10(1), 117; https://doi.org/10.3390/nano10010117 - 8 Jan 2020

Cited by 61 | Viewed by 7404

Abstract

In this study, silica-coated magnetic iron oxide nanoparticles (MNPs@SiO₂) were covalently conjugated onto graphene oxide (GO/MNP@SiO₂) for protein isolation. First, MNPs were precisely coated with a silica layer on the surface by using the reverse microemulsion method, followed by [...] Read more.

In this study, silica-coated magnetic iron oxide nanoparticles (MNPs@SiO₂) were covalently conjugated onto graphene oxide (GO/MNP@SiO₂) for protein isolation. First, MNPs were precisely coated with a silica layer on the surface by using the reverse microemulsion method, followed by incubation with 3-glycidyloxypropyltrimethoxysilane (GPTS) to produce the GPTS-functionalized MNPs@SiO₂ (GPTS-coated MNPs@SiO₂) that display epoxy groups on the surface. The silica shell on the MNPs was optimized at 300 µL of Igepal^®CO-520, 5 mg of MNP, 100 µL of TEOS, 100 µL of NH₄OH and 3% of 3-glycidyloxypropyltrimethoxysilane (GPTS). Simultaneously, polyethyleneimine (PEI) was covalently conjugated to GO to enhance the stability of GO in aqueous solutions and create the reaction sites with epoxy groups on the surface of GPTS-coated MNP@SiO₂. The ratio of PEI grafted GO and GPTS-coated MNP@SiO₂ (GO/MNP ratio) was investigated to produce GO/MNPs@SiO₂ with highly saturated magnetization without aggregation. As a result, the GO/MNP ratio of 5 was the best condition to produce the GO/MNP@SiO₂ with 9.53 emu/g of saturation superparamagnetization at a magnetic field of 2.0 (T). Finally, the GO/MNPs@SiO₂ were used to separate bovine serum albumin (BSA) to investigate its protein isolation ability. The quantity of BSA adsorbed onto 1 mg of GO/MNP@SiO₂ increased sharply over time to reach 628 ± 9.3 µg/mg after 15 min, which was 3.5-fold-higher than that of GPTS-coated MNP@SiO₂. This result suggests that the GO/MNP@SiO₂ nanostructure can be used for protein isolation. Full article

(This article belongs to the Special Issue Nano-Hybrids: Synthesis, Characterization and Applications)

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