scholarly journals Fabrication and Enhanced Thermal Conductivity of Boron Nitride and Polyarylene Ether Nitrile Hybrids

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1340 ◽  
Author(s):  
Ling Tu ◽  
Qian Xiao ◽  
Renbo Wei ◽  
Xiaobo Liu
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Thermal Resistance ◽  
Photoelectron Spectroscopy ◽  
Elevated Temperatures ◽  
Crosslinking Reaction ◽  
X Ray ◽  
Polyarylene Ether Nitrile ◽  
Ft Ir ◽  
Cyano Groups

Excellent thermal resistance and thermal conductivity are preconditions of materials to be used at elevated temperatures. Herein, boron nitride and polyarylene ether nitrile hybrids (PEN-g-BN) with excellent thermal resistance and thermal conductivity are fabricated. Phthalonitrile-modified BN (BN-CN) is prepared by reacting hydroxylated BN with isophorone diisocyanate (IPDI) and 3-aminophxylphthalonitrile (3-APN), and then characterized by FT-IR, UV-Vis, and X-ray photoelectron spectroscopy (XPS). The obtained BN-CN is introduced to a phthalonitrile end-capped PEN (PEN-Ph) matrix to prepare BN-CN/PEN composites. After curing at 340 °C for 4 h, PEN-g-BN hybrids are fabricated by a self-crosslinking reaction of cyano groups (-CN) from BN-CN and PEN-Ph. The fabricated PEN-g-BN hybrids are confirmed through FT-IR, UV-Vis, SEM and gel content measurements. The PEN-g-BN hybrids demonstrate excellent thermal resistance with their glass transition temperature (Tg) and decomposition temperatures (Td) being higher than 235 °C and 530 °C, respectively. Additionally, the thermal conductivity of the prepared PEN-g-BN hybrids is up to 0.74 W/(m·k), intensifying competitiveness of PEN-g-BN hybrids for applications at elevated temperatures.

scholarly journals Hexagonal Boron Nitride/Microfibril Cellulose/Poly(vinyl alcohol) Ternary Composite Film with Thermal Conductivity and Flexibility

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 104 ◽  
Author(s):  
Xin Ge ◽  
Wei-Jie Liang ◽  
Jian-Fang Ge ◽  
Xun-Jun Chen ◽  
Jian-Ye Ji ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Boron Nitride ◽  
Composite Film ◽  
Photoelectron Spectroscopy ◽  
Vinyl Alcohol ◽  
Hexagonal Boron Nitride ◽  
Poly Vinyl Alcohol ◽  
Thermal Interface Materials ◽  
Binding Effect ◽  
Ft Ir

Microfibril cellulose (MFC), which is detrimental to soil cultivation and environmental protection, is derived from waste pineapple leaves. Hexagonal boron nitride (h-BN) was modified with polydopamine (PDA)—PDA@h-BN named pBN, and then combined with MFC to prepare a novel hybrid powder. The effect of PDA on h-BN and the binding effect between pBN and MFC were characterized by X-ray photoelectron spectroscopy (XPS), Thermogravimetric (TG), scanning electron microscopy (SEM), and Fourier Transform-Infrared (FT-IR). Poly (vinyl alcohol) (PVA) was used as an eco-friendly polymeric matrix to prepare a pBN-MFC-PVA composite film. The mechanical strength, hydrophobicity, and thermal conductivity of the film were studied and the results confirmed that h-BN was chemically modified with PDA and was uniformly distributed along the MFC. The thermal conductivity of the pBN-MFC-PVA composite film increased with the addition of a pBN-MFC novel powder. MFC acted as “guides” to mitigate the h-BN agglomerate. In addition to the possible usage in the pBN-MFC-PVA composite film itself, the pBN-MFC hybrid powder may be a potential filler candidate for manufacturing thermal interface materials and wearable devices or protective materials.

Sonochemical Functionalization of Boron Nitride Nanomaterials

MRS Advances ◽  
2019 ◽  
Vol 5 (14-15) ◽  
pp. 709-716
Author(s):  
Haley B. Harrison ◽  
Jeffrey R. Alston
Keyword(s):  
Thermal Stability ◽  
Boron Nitride ◽  
Photoelectron Spectroscopy ◽  
Colloidal Stability ◽  
Hexagonal Boron Nitride ◽  
Boron Nitride Nanotubes ◽  
Covalent Attachment ◽  
Covalent Functionalization ◽  
X Ray ◽  
Ft Ir

AbstractBoron nitride nanotubes (BNNTs) and hexagonal boron nitride platelets (h-BNs) have received considerable attention for aerospace insulation applications due to their exceptional chemical and thermal stability. Presently, making BN nanomaterials compatible with polymer and composite matrices is challenging. Due to their inert and highly stable structure, h-BN and BNNTs are difficult to covalently functionalize. In this work, we present a novel sonochemical technique that enables covalent attachment of fluoroalkoxy substituents to the surface of BN nanomaterials in a controlled and metered process. Covalent functionalization is confirmed via colloidal stability analysis, FT-IR, and x-ray photoelectron spectroscopy (XPS).

scholarly journals Comparative Study of Carbon Nanosphere and Carbon Nanopowder on Viscosity and Thermal Conductivity of Nanofluids

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 608
Author(s):  
Thong Le Ba ◽  
Marcell Bohus ◽  
István Endre Lukács ◽  
Somchai Wongwises ◽  
Gyula Gróf ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Analysis ◽  
Fourier Transform ◽  
Photoelectron Spectroscopy ◽  
Comparative Research ◽  
Base Fluid ◽  
X Ray ◽  
Ft Ir ◽  
High Concentrations ◽  
Scanning Electron

A comparative research on stability, viscosity (µ), and thermal conductivity (k) of carbon nanosphere (CNS) and carbon nanopowder (CNP) nanofluids was performed. CNS was synthesized by the hydrothermal method, while CNP was provided by the manufacturer. Stable nanofluids at high concentrations 0.5, 1.0, and 1.5 vol% were prepared successfully. The properties of CNS and CNP nanoparticles were analyzed with Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), specific surface area (SBET), X-ray powder diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), and energy dispersive X-ray analysis (EDX). The CNP nanofluids have the highest k enhancement of 10.61% for 1.5 vol% concentration compared to the base fluid, while the CNS does not make the thermal conductivity of nanofluids (knf) significantly higher. The studied nanofluids were Newtonian. The relative µ of CNS and CNP nanofluids was 1.04 and 1.07 at 0.5 vol% concentration and 30 °C. These results can be explained by the different sizes and crystallinity of the used nanoparticles.

scholarly journals Synthesis of Magnetic Ferrocene-Containing Polymer with Photothermal Effects for Rapid Degradation of Methylene Blue

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 558
Author(s):  
Wenhui Zhu ◽  
Caiyun Zhang ◽  
Yali Chen ◽  
Qiliang Deng
Keyword(s):  
Methylene Blue ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Degradation Rate ◽  
Model Compound ◽  
Vibrating Sample Magnetometer ◽  
Simulated Sunlight ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir

Photothermal materials are attracting more and more attention. In this research, we synthesized a ferrocene-containing polymer with magnetism and photothermal properties. The resulting polymer was characterized by Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). Its photo-thermocatalytic activity was investigated by choosing methylene blue (MB) as a model compound. The degradation percent of MB under an irradiated 808 nm laser reaches 99.5% within 15 min, and the degradation rate is 0.5517 min−1, which is 145 times more than that of room temperature degradation. Under irradiation with simulated sunlight, the degradation rate is 0.0092 min−1, which is approximately 2.5 times more than that of room temperature degradation. The present study may open up a feasible route to degrade organic pollutants.

Chemical Structures of Native Oxides Formed During Wet Chemical Treatments on NH4F Treated Si(111) Surfaces

1992 ◽  
Vol 259 ◽  
Author(s):  
Takeo Hattori ◽  
Hiroki Ogawa
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflection ◽  
Native Oxide ◽  
X Ray ◽  
Chemical Treatments ◽  
Chemical Structures ◽  
Native Oxides ◽  
Ft Ir ◽  
Wet Chemical ◽  
Silicon Interface

ABSTRACTChemical structures of native oxides formed during wet chemical treatments on NH4F treated Si(111) surfaces were investigated using X-ray Photoelectron Spectroscopy (XPS) and Fourier Transformed Infrared Attenuated Total Reflection(FT-IR-ATR). It was found that the amounts of Si-H bonds in native oxides and those at native oxide/silicon interface are negligibly small in the case of native oxides formed in H2SO4-H2O2-H2O solution. Based on this discovery, it was confirmed that native oxides can be characterized by the amount of Si-H bonds in native oxides. Furthermore, it was found that the combination of various wet chemical treatments with the treatment in NH4OH-H2O2-H2O solution results in the drastic decrease in the amount of Si-H bonds in native oxides.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

scholarly journals Dual Light- and pH-Responsive Composite of Polyazo-Derivative Grafted Cellulose Nanocrystals

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1725 ◽  
Author(s):  
Xiaohong Liu ◽  
Ming Li ◽  
Xuemei Zheng ◽  
Elias Retulainen ◽  
Shiyu Fu
Keyword(s):  
Cellulose Nanocrystals ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
X Ray Diffraction ◽  
Responsive Materials ◽  
X Ray ◽  
Ph Response ◽  
Transmission Electron ◽  
Ft Ir ◽  
Hexyl Methacrylate

As a type of functional group, azo-derivatives are commonly used to synthesize responsive materials. Cellulose nanocrystals (CNCs), prepared by acid hydrolysis of cotton, were dewatered and reacted with 2-bromoisobuturyl bromide to form a macro-initiator, which grafted 6-[4-(4-methoxyphenyl-azo) phenoxy] hexyl methacrylate (MMAZO) via atom transfer radical polymerization. The successful grafting was supported by Fourier transform infrared spectroscopy (FT-IR) and Solid magnetic resonance carbon spectrum (MAS 13C-NMR). The morphology and surface composition of the poly{6-[4-(4-methoxyphenylazo) phenoxy] hexyl methacrylate} (PMMAZO)-grafted CNCs were confirmed with Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). The grafting rate on the macro-initiator of CNCs was over 870%, and the polydispersities of branched polymers were narrow. The crystal structure of CNCs did not change after grafting, as determined by X-ray diffraction (XRD). The polymer PMMAZO improved the thermal stability of cellulose nanocrystals, as shown by thermogravimetry analysis (TGA). Then the PMMAZO-grafted CNCs were mixed with polyurethane and casted to form a composite film. The film showed a significant light and pH response, which may be suitable for visual acid-alkali measurement and reversible optical storage.

Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

2005 ◽  
Vol 13 (8) ◽  
pp. 839-846 ◽  
Author(s):  
Li-Ping Wang ◽  
Yun-Pu Wang ◽  
Fa-Ai Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Alcohol Water ◽  
Ft Ir ◽  
Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

scholarly journals Preparation and characterization of self-cleaning cotton fabric loaded with self-dispersive and reactive biphasic TiO2

2021 ◽  
Author(s):  
Kuang Wang ◽  
Jiayi Chen ◽  
Jialong Tian ◽  
Dawei Gao ◽  
Xiaolei Song ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Cotton Fabrics ◽  
Ammonia Solution ◽  
X Ray ◽  
Washing Fastness ◽  
Fastness Property ◽  
Structure Dispersion ◽  
Ft Ir ◽  
Self Cleaning

Abstract In this article, amino functionalized TiO2 (TiO2/KH550) was obtained in a mild reaction between 3-aminopropyltriethoxysilane and TiO2 with the aid of concentrated ammonia solution. 4-(4,6-dichloro-1,3,5-triazine-2-yl) amino) sodium benzenesulfonate (SAT) was synthesized and characterized by 1H NMR and fourier transform infrared spectroscopy (FT-IR). Self-dispersive and reactive TiO2 (TiO2/KH550/SAT) was prepared by nucleophile substitution reaction between TiO2/KH550 and SAT. Finally, cotton fabrics loaded with different amounts of TiO2/KH550/SAT were achieved by pad-dry-cure method. The chemical structure, dispersion and thermal performance of TiO2, TiO2/KH550 and TiO2/KH550/SAT were investigated by FT-IR, zeta potential and thermogravimetric analysis (TG). The crystalline phase, morphology, chemical composition and optical absorption property of cotton fabrics were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). Moreover, the anti-ultraviolet, self-cleaning and washing fastness properties of cotton fabrics were investigated. It has been found that TiO2/KH550/SAT demonstrated excellent dispersion stability in aqueous even after standing for a month. Cotton fabrics loaded with TiO2/KH550/SAT possessed adorable anti-ultraviolet performance, highly efficient and durable self-cleaning activity as well as appreciable washing fastness property. The mechanism and possible reactions for the preparation of self-cleaning cotton fabrics loaded with TiO2/KH550/SAT were proposed.

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