Fourier Transmission Infrared Spectra Research Articles

Fabrication of abundantly functionalized dendritic biochar composites as adsorbents for the high-efficiency removal of heavy metal ions and dyes

A novel polymer modified biochar composite material (MNBC@p(HGMA-co-PSS-b-AA)) with dendritic structure, abundant functional groups and easy recovery was synthesized, which exhibited excellent removal capacity for Cr(VI), Lemon-Yellow (LY) and Malachite Green (MG). The prepared MNBC@p(HGMA-co-PSS-b-AA) was characterized via thermogravimetric analysis (TGA), scanning electron microscope (SEM) and Fourier transmission infrared spectra (FT-IR), proving to be with abundant functional groups and pore structure. The adsorption capacities for Cr(VI), LY and MG were 421.79, 1169.14 and 1231.53 mg/g, respectively, surpassing the capacities of most previously reported materials in recent years. Additionally, the effects of many factors on adsorption performance were explored. Experimental results indicated that the adsorption of Cr(VI), LY and MG on MNBC@p(HGMA-co-PSS-b-AA) followed pseudo-second-order and Langmuir models. Furthermore, MNBC@p(HGMA-co-PSS-b-AA) still displayed excellent removal capacity for Cr(VI), LY and MG after five reuse cycles. Moreover, different real water samples such as lake water, tap water were used to measure removal efficiency of Cr(VI), LY and MG. The results indicated that removal rates of Cr(VI), LY, and MG were not less than 86.26 %, 98.25 %, and 97.98 %. Meanwhile, MNBC@p(HGMA-co-PSS-b-AA) could maintain removal rate of 85.35 % even after continuously filtering a large number of pollutants solution in adsorption column, revealing its promising applicability for efficient removal of dyes and heavy metal ions. Surprisingly, MNBC@p(HGMA-co-PSS-b-AA) not only quickly adsorbed Cr(VI), but also enabled the concentration of Cr(VI) after adsorption to meet the World Health Organization standard for drinking water. Additionally, FT-IR and X-ray photoelectron spectroscopy (XPS) analysis suggested that adsorption mechanisms for Cr(VI) were hole filling, redox reaction and electrostatic interaction and adsorption mechanisms for LY and MG were hole filling, π–π interaction, π–π electron donor–acceptor (π–π EDA) interaction, electrostatic interaction and hydrogen bond.

Cr(VI) anion-imprinted polymer synthesized on mesoporous silicon via synergistic action of bifunctional monomers for precise identification and separation of Cr(VI) from aqueous solution by fixed-bed adsorption.

The novel Cr(VI) anion-imprinted polymer (Cr(VI)-IIP) was prepared by a surface imprinting technique with bifunctional monomers pre-assembly system based on mesoporous silicon (SBA-15). The synthesized Cr(VI)-IIP was characterized by Fourier transmission infrared spectra (FT-IR), energy dispersive spectrometer (EDS), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray powder diffractometer, N2 adsorption-desorption and thermogravimetric analysis (TGA), proving to be with a highly ordered mesoporous structure, as well as favorable thermal stability. The saturated adsorption amount was 96.32 mg/g, which was 2.7 times higher than that of non-imprinted polymer (NIP). Kinetic experiments showed that the adsorption equilibrium state was obtained within 70 min. In addition, in the selectivity experiments, Cr(VI)-IIP exhibited strong specific recognition ability for Cr(VI) and could realize the separation of Cr(VI) and Cr(III) from an aqueous solution. The dynamic adsorption experiments exhibited that the dynamic adsorption efficiency of Cr(VI)-IIP was as high as 71.57%. Meanwhile, the dynamic regeneration experiments showed that the adsorption amount of Cr(VI)-IIP did not decrease significantly after repeating for five times. All of the findings suggested that Cr(VI)-IIP could achieve precise identification as well as efficient separation of Cr(VI) from aqueous solution.

Magnetite-supported montmorillonite (K10) (nanocat-Fe-Si-K10): an efficient green catalyst for multicomponent synthesis of amidoalkyl naphthol.

Montmorillonite (K10) loaded on magnetite silica-coated nanoparticles was made using simple co-precipitation methods. The prepared nanocat-Fe-Si-K10 was analyzed using some techniques including field emission-scanning electron microscopy (FE-SEM), inductive coupling plasma-optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), Fourier transmission-infrared spectra (FT-IR), energy dispersive X-ray spectroscopy (EDS), and wavelength-dispersive spectroscopy (WDX). The catalytic activity of the synthesized nanocat-Fe-Si-K10 has been examined in one-pot multicomponent transformations for the synthesis of 1-amidoalkyl 2-naphthol derivatives under solvent-free conditions. Nanocat-Fe-Si-K10 was determined to be very active, having the ability to be reused 15 times without significant loss of catalytic activity. The suggested technique has several advantages, including excellent yield, minimum reaction time, a straightforward workup, and catalyst recycling, all of which are essential green synthetic aspects.

Site Occupancy, Surface Morphology and Mechanical Properties of Ce3+ Added Ni–Mn–Zn Ferrite Nanocrystals Synthesized Via Sol–Gel Route

Ferrite nanoparticles of Ni[Formula: see text]Mn[Formula: see text]Zn[Formula: see text]Fe[Formula: see text]CexO4 ferrite system were produced using sol–gel auto combustion technique. X-ray diffraction analysis confirms the single phase cubic spinel structure of the samples with space group Fd-3m. Replacement of Fe[Formula: see text] ions by Ce[Formula: see text] ions increases the lattice parameter 8.4105 Å to 8.4193. Average crystallite size obtained from Scherrer method varies from 21.73[Formula: see text]nm to 22.71[Formula: see text]nm with replacement of Fe[Formula: see text] ions by Ce[Formula: see text] ions. Williamson–Hall and strain-size plot analysis confirms the nanocrystalline nature of the samples and the micro-strain induced in the cubic crystals is of tensile type. Cation distribution suggests that Zn[Formula: see text] ions occupy tetrahedral — A-site while Ni[Formula: see text] ions occupy octahedral — B-site. Majority of the Mn[Formula: see text] ions prefer A-site and majority of the Ce[Formula: see text] ions replace Fe[Formula: see text] ions at octahedral — B-site. High resolution transmission images confirm the homogeneity and nanoparticle nature of the samples. Two main characteristics absorption bands corresponding to spine structure are observed in the Fourier transmission infra-red spectra within the wavenumber range of 350–600[Formula: see text]cm[Formula: see text]. Stiffness constant, Young’s modulus, rigidity modulus, bulk modulus and Debye temperature were estimated using FTIR data. Debye temperature obtained from the Waldron equation varies from 676[Formula: see text]K to 692[Formula: see text]K with the addition of Ce[Formula: see text] ions. Higher values of elastic moduli are suitable for industrial applications due to increased mechanical strength.

A novel synthesis of zinc oxide nanoparticles using various carbohydrate sources and its antimicrobial effects

In the present study, ZnONPs were synthesized using various carbohydrates sources such as maltose, dextrose, and fructose extract for the first time by precipitation method. The various carbohydrates sources act as efficient, reducing as well as stabilizing agents. The biologically synthesized Zinc oxide nanoparticles were characterized by Scanning Electron Microscope (SEM), UV–visible spectrophotometer (UV), Fourier Transmission Infrared Spectra (FTIR), X-Ray Diffraction (XRD), Zeta Potential and Particle Size analysis. The UV results indicated the formation of ZnONPs around 200–400 nm. FTIR studies showed the presence of various functional groups responsible for the synthesis of ZnONPs. Morphological analysis using SEM revealed the spherical and cube-shaped structures of the ZnONPs. XRD analysis revealed the high crystalline nature of the synthesized nanomaterials. Zeta potential showed the high stability of the nanomaterials synthesized. In order to determine the antimicrobial activity, the synthesized ZnONPs were treated against gram-positive and gram-negative bacteria such as Staphylococcus epidermidis and Enterobacter aerogenes, and the results showed high activity of ZnONPs synthesized from fructose. The study highlighted the high antimicrobial activity of biologically synthesized ZnONPs.

The effect of changing injection temperature on some mechanical and morphological properties for polypropylene material (PP)

Abstract This is a study of a medical injection factory-Babylon carried out in order to achieve proper mechanical and morphological properties, PP has been injection molded by using cold runner injection molding machine with temperature variation (198, 200, 203……220°C) for ten samples. The physical and mechanical properties of PP product were examined. It has been found that the Shore hardness decreases linearly with injection molding temperature increasing. The tensile strength has a similar behavior to the hardness. However, it has been found that the MIF (Melt Index Flow) rates increases with the increase of injection molding temperature. The density of PP has been found for both virgin PP and the samples, it has been found that the density decreases with increasing operation temperature. FTIR (Fourier Transmission Infrared) spectra were taken for both samples with high and low operation temperature. Besides the SEM (Scanning Electronic Microscopy) test shows the difference in the morphology of the product surface and the PP product at high and low operation temperature. Moreover, for all these properties, the PP product exhibits good mechanical properties (hardness, tensile strength, density) for the samples produced at temperature lower than 207°C. While the physical properties such as MIF improved with injection temperature increasing, additionally, the SEM images show that the sample produced in low temperature have surface damage.

Mixed structure Zn(S,O) nanoparticles: synthesis and characterization

Abstract In the present work, mixed structure Zn(S,O) nanoparticles have been synthesized using solution based chemical coprecipitation technique. Two different zinc sources (Zn(CH3COO)2·2H2O and ZnSO4·7H2O) and one sulfur source (CSNH2NH2) have been used as primary chemical precursors for the synthesis of the nanoparticles in the presence and absence of a capping agent (EDTA). The structural, morphological, compositional and optical properties of the nanoparticles have been analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transmission infra-red (FT-IR) and UV-Visible (UV-Vis) spectroscopy. XRD revealed the formation of mixed phases of c-ZnS, h-ZnS and h-ZnO in the synthesized nanoparticles. The surface morphology was analyzed from SEM micrographs which showed noticeable changes due to the effect of EDTA. EDX analysis confirmed the presence of zinc, sulfur and oxygen in Zn(S,O) nanoparticles. FT-IR spectra identified the presence of characteristic absorption peaks of ZnS and ZnO along with other functional group elements. The optical band gap values were found to vary from 4.16 eV to 4.40 eV for Zn(S,O) nanoparticles which are higher in comparison to the band gap values of bulk ZnS and ZnO. These higher band gap values may be attributed to the mixed structure of Zn(S,O) nanoparticles.

Effect of Cr3+ Substitution on the Structural, Electrical and Magnetic Properties of Ni0.7Zn0.2Cu0.1Fe2−xCrxO4 Ferrites

In this work, Ni0.7Zn0.2Cu0.1Fe2−xCrxO4 (x = 0.02, 0.04, 0.06, 0.08 and 0.1) ferrites were synthesized by using the solid state reaction method and how relevant properties of the samples were modified accordingly. The structural, morphological, magnetic and electrical features of the ferrites were evaluated by using X-ray diffraction, scanning electron microscopy, Fourier transmission infrared (FTIR) spectra, vibrating sample magnetometry, electron spin resonance and network analyser. The lattice constant decreases with increasing chromium concentration and the decrease in the lattice constant is attributed to the ionic radius of chromium being smaller than that of iron. The distribution of metal cations in the spinel structure was estimated from the X-ray diffraction data and showed that along with Ni2+ ions, most of the Zn2+ and the Cu2+ ions additionally occupied the octahedral [B] sites. The FTIR spectra revealed two prominent frequency bands in the wave number range 400–600 cm−1 which confirm the cubic spinel structure. The magnetic properties, such as the initial permeability, saturation magnetization and coercivity, were investigated at room temperature. The frequency-dependent dielectric constant was observed to decrease with increasing chromium concentration. This behavior was using Koops phenomenological theory.

A Novel Electrochemical Sensor Based on Graphene Oxide Decorated with Silver Nanoparticles–Molecular Imprinted Polymers for Determination of Sunset Yellow in Soft Drinks

In this study, a new imprinted electrochemical sensor for selectively detecting sunset yellow was developed based on glassy carbon electrode (GCE) modified by graphene oxide decorated with silver nanoparticles–molecular imprinted polymers (GO/AgNPs–MIPs). GO/AgNPs were firstly synthesized using self-assembly technology, and GO/AgNPs–MIPs were synthesized through surface imprinted technology by using GO/AgNPs as the substrate and sunset yellow as the template, respectively. The sensor was prepared by a drop-casting method. The synthetic materials were characterized by transmission electron microscope (TEM), Fourier transmission infrared spectra (FT-IR), and X-ray diffraction (XRD). The sensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The usage amount of GO/AgNPs–MIPs suspensions, solution pH, and accumulation time made an important difference in the process of detecting sunset yellow. Under optimal conditions, the peak current is linear to concentration of sunset yellow in the ranges of 0.1–0.6 and 0.6–12 μM, and the limit of detection was estimated to be 0.02 μM (S/N = 3). Finally, the proposed sensor was applied to detect sunset yellow in soft drinks with acceptable recovery, which demonstrated that the sensor could be used as a reliable and simple method for practical detection of sunset yellow.

Biodiesel production from soybean oil deodorizer distillate usingcalcined duck eggshell as catalyst

Biodiesel production from soybean oil deodorizer distillate (SODD) using calcined duck eggshell (DES) as catalyst was studied. An inexpensive and environment-friendly catalyst was prepared from waste DES which is a source of calcium carbonate. The calcium carbonate could be changed to calcium oxide (CaO) under high temperatures. The obtained CaO was characterized by X-ray diffraction (XRD), Fourier Transmission Infrared Spectra (FT-IR), Scanning Electron Microscopy (SEM). XRF was used to determine the elemental composition of the catalyst. BET analysis was performed to determine specific surface area, pore volume and particle size of the catalysts. Results showed that at 800°C and 900°C the calcium carbonate in DES was changed to CaO. The pre-esterification of SODD was conducted under the following conditions: H2SO4 concentration (v/w, based on oil weight) 1.5%, methanol to oil molar ratio 12:1, reaction time 120min and reaction temperature 60°C. Thephytosterols were removed by cooling down step by stepand temperature steps were 15°C, 5°C, −5°C. The process of biodiesel production from pre-esterified SODD using the obtained CaO as catalyst was studied and the optimal conditions were: calcination temperature of 900°C, catalyst amount of 10wt.%, methanol to oil ratio of 10:1, reaction temperature of 60°C and reaction time of 80min and the biodiesel yield was 94.6% at these conditions. The reusability of the DES-derived catalyst was tested and the results showed that the biodiesel yield was above 80% after five times usage and was lower than 60% after 8 times usage.

The Variation of Magnetic Properties of Nickel Ferrite by Annealing

Nickel ferrite nanoparticles were synthesized by Co-precipitation method. The prepared powder was annealed at 500℃, 700℃ and 900℃. XRD analysis was used for composition and structure investigation. The detection and confirmation of the chemical bond in spinel ferrites were investigated by Fourier transmission infrared spectra (FTIR). Also the magnetic properties of the samples were measured by using a vibrating sample magnetometer (VSM). The XRD analysis revealed a pure ferrite phase with high crystallinity. The average crystallite size calculated by Sherrer's equation resulted in variation crystallite size from 9 to 21 nm depending upon the annealing temperature of the samples. FTIR analysis shows the presence of two vibrational bonds between 400-650 cm -1 corresponding to metal-oxygen interaction at tetrahedral and octahedral sites, respectively. Increasing the annealing temperature gave rise to the enhancement of saturation magnetization from 6 to 31emu/gr and the variation of coercivity between 2 and 80Oe.

Synthesis, Infrared spectroscopic and Thermal studies of [0.7(Cu2CdI4):0.3(AgIx:CuI(1-x))] of fast-ion conductor (x = 0.2, 0.4, 0.6 and 0.8 mol. wt. %)

An efforts were made to prepare some fast ionic solids in the mixed system [0.7(Cu2CdI4):0.3(AgIx:CuI(1-x))] where x = 0.2, 0.4, 0.6 and 0.8 mol. wt. % respectively by solid state reaction of the appropriate solid mixtures and quenching them at particular temperature. Powdered samples of different compositions containing x mol. wt. % of (AgIx:CuI(1-x)) were synthesized by solid state reactions, using [Cu2CdI4] ternary halides as host. Powder specimens of these compositions were analyzed using differential thermal analysis (DTA), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), Fourier transmission infrared spectra (FTIR) and x-ray powder diffraction (XRD) techniques. These studies have confirmed the formation of new products as revealed by the absence of diffraction peaks of parent materials in the XRD patterns. Among the various compositions, a significant number of peaks found to contain Ag+ and Cu+ in Cu2CdI4 respectively and DSC traces have indicated the characteristic β-α phase transition temperature of [0.7(Cu2CdI4):0.3(AgIx:CuI(1-x))] at around 611K, 635K, 631K and 436K in x = 0.2, 0.4, 0.6 and 0.8 respectively. These changes due to crystalline defects or on increased Cu+-free volume in the tetragonal lattice. In addition, Ag and Cu substitution appears to stabilize the high-temperature, hexagonal structure to temperature well in excess of 523K, associated Correspondingly with the melting of the (Ag+:Cu+) sublattice and with the storage of iodide/or cadmium sublattices. Fourier transmission infrared spectra of all the the fast ionic conductors [0.7(Cu2CdI4):0.3(AgIx:CuI(1-x))] (where x = 0.2, 0.4, 0.6 and 0.8 mol. wt. %) in the wavenumber range extending from 400 to 4000 cm−1 are also reported. FTIR measurements can provide information on the motion and environment of the ions.

Green synthesis and characterization of Au@Pt core–shell bimetallic nanoparticles using gallic acid

In this study, we developed a facile and benign green synthesis approach for the successful fabrication of well-dispersed urchin-like Au@Pt core–shell nanoparticles (NPs) using gallic acid (GA) as both a reducing and protecting agent. The proposed one-step synthesis exploits the differences in the reduction potentials of AuCl4− and PtCl62−, where the AuCl4− ions are preferentially reduced to Au cores and the PtCl62− ions are then deposited continuously onto the Au core surface as a Pt shell. The as-prepared Au@Pt NPs were characterized by transmission electron microscope (TEM); high-resolution transmission electron microscope (HR-TEM); scanning electron microscope (SEM); UV-vis absorption spectra (UV-vis); X-ray diffraction (XRD); Fourier transmission infrared spectra (FT-IR). We systematically investigated the effects of some experimental parameters on the formation of the Au@Pt NPs, i.e., the reaction temperature, the molar ratios of HAuCl4/H2PtCl6, and the amount of GA. When polyvinylpyrrolidone K-30 (PVP) was used as a protecting agent, the Au@Pt core–shell NPs obtained using this green synthesis method were better dispersed and smaller in size. The as-prepared Au@Pt NPs exhibited better catalytic activity in the reaction where NaBH4 reduced p-nitrophenol to p-aminophenol. However, the results showed that the Au@Pt bimetallic NPs had a lower catalytic activity than the pure Au NPs obtained by the same method, which confirmed the formation of Au@Pt core–shell nanostructures because the active sites on the surfaces of the Au NPs were covered with a Pt shell.

Thermal-responsive ion-imprinted polymer based on magnetic mesoporous silica SBA-15 for selective removal of Sr(II) from aqueous solution

Highly thermal-responsive magnetic Sr(II)-imprinted polymer (Sr(II)-TMIIP) was successfully synthesized as a potential effective adsorbent for selective removal of Sr(II) in aquatic environments. First, magnetic polyethyleneimine-loaded mesoporous SBA-15 (Fe3O4@PEI-SBA-15) was prepared via a simple polymer-mediated self-assembly method. Then, the surface of Fe3O4@PEI-SBA-15 was endowed with reactive vinyl groups through modification with 3-(methacryloyloxy)propyl trimethoxysilane (MPS). With the aid of vinyl groups, free radical polymerization of N-isopropylacrylamide (NIPAM), methacrylic acid (MAA), and N,N′-methylenebisacrylamide (BIS) in the presence of Sr(II) was performed with 2,2′-azobisisobutyronitrile (AIBN) as initiator, which provided a desired imprinted layer coating onto Fe3O4@PEI-SBA-15. The as-prepared Sr(II)-TMIIP was characterized by Fourier transmission infrared spectra (FT-IR), X-ray diffractometer (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM), UV, and N2 adsorption–desorption techniques. The results showed that the Sr(II)-TMIIP exhibited thermal stability, temperature and magnetic sensitivity (M s = 10.34 emu/g), and ordered mesoporous structure. Batch mode adsorption studies were conducted to investigate the specific binding kinetics, adsorption equilibrium, and selective recognition ability of Sr(II)-TMIIP. Adsorption equilibrium experiments showed that the adsorption amount strongly depended on temperature and reached a maximum around the lower critical solution temperature (LCST). Regeneration experiments indicated that repeated adsorption and desorption by temperature swings were possible. Compared with the nonimprinted polymer (NIP), the Sr(II)-TMIIP had good temperature response and excellent selectivity and reusability, making it possible in applying for Sr(II) separation and controlled release.

Theoretical and experimental approach on dielectric properties of ZnO nanoparticles and polyurethane/ZnO nanocomposites

ZnO nanoparticles (ZnO-NPs) were synthesized by a new, simple sol-gel method in gelatin media (particle size of ZnO ≈ 30 to 60 nm). Polyurethane/ZnO nanocomposites thin films (PU/ZnO-NPs) were prepared by mixing the ZnO-NPs into PU prepolymer. The nanocomposites were structurally characterized using Fourier transmission infrared (FTIR) spectroscopy. The interaction between ZnO-NPs and PU matrix is studied by analyzing the differences in C=O region and N-H region of FTIR spectra. The morphology of ZnO and PU/ZnO nanocomposites were assessed using transmission electron micrograph, TEM, and field emission scanning electron microscope, FESEM, respectively. The dielectric properties of ZnO-NPs were attributed to the interfacial and orientation polarization. Measurement is reported for the real and imaginary parts of the ac conductivity of ZnO-NPs in the frequency range of 10 to 106 Hz in the temperature range 298–478 K. The experimental results are interpreted in terms of the classical correlated-barrier hopping theory. In addition, the dielectric properties of PU/ZnO nanocomposites (0–15 vol. % filler concentration) were analyzed with respect to frequency. Quantitative analysis based on mixing laws for two-phase spherical dispersion system such as Lichtenecker, Maxwell, Jayasundere and Smith, and Yamada equations was used to predict the effective permittivity accurately up to 15 vol. % of ZnO in PU matrix.

O] [H] functionalization on carbon nanotube using (O2–H2) gas mixture DC glow discharge

The (O) (H) functionalization of carbon nano- tube (CNT) was studied using oxygen-hydrogen (O2-H2) gas mixture direct current (DC) glow discharge plasma technique for cathode/CNT-anode separation of 0.10 ± 0.01 cm. O2 and H2 were fixed at flowrate of 10.0 ml/min in order to obtain gas mixture ratio of 1:1. During the (O2-H2) gas mixture DC glow discharge, current-voltage (I-V) characteristic of gaseous species studied for various settings of gas pressures 1, 2, 3 and 4 mbar. The voltage at gap between cathode/CNT and anode, a breakdown voltage, was identified as ''functionalization voltage'' (Vfunc). Vfunc was noticed responsible for functionalization of functional groups on sidewall of CNT. The Vfunc were recorded as 796, 707, 594, and 663 V for gas pressures of 1, 2, 3 and 4 mbar, respectively. The co-relation between Vfunc and gas pressure was identified as linear relationship. But a voltage obtained due to the CNT/Cathode fall shows exponential relationship with the gas pressures. The possibility of (O) (H) functional- ization was proved using Fourier transmission infra-red (FTIR) spectroscopy. Hydroxyl (-OH), carboxyl (-COOH), and carbonyl (-C=O) functional groups were identical as identified in the FTIR spectra. The field emission scanning electron microscope images show significant changes in the morphology of CNT which proves that the DC gas discharge plasma is a possible technique for (O) (H) functionalization on the sidewall of CNT.

THE EFFECT OF DIFFERENT PARAMETERS ON THE FUNCTIONALIZATION OF MWCNTs VIA ACID TREATMENT

In this report, the functionalization of MWCNTs in sulfuric/nitric acid is studied, and the influences of acid concentration, temperature and time on functionalization are assessed. Fourier Transmission Infrared (FTIR) spectroscopy was employed to study the functional groups of different samples. The optimal results for complete functionalization were achieved by the addition of 5 mg/ml of MWCNTs to acid, at a temperature of 100°C with 3 h of soaking time. The correlation between the FTIR and Raman spectra of the optimized sample was determined, and the effect of functional groups on the G and D bands is discussed.

Synthesis and characterization of water-soluble gold colloids stabilized with aminoresorcinarene

An aminoresorcinarene (TOMR) with eight amino groups as a novel ligand was synthesized and the fabrication of gold hydrosol stabilized with TOMR was reported in this paper. The TOMR-capped gold nanoparticles were characterized and analyzed by the ultraviolet visible (UV–vis) spectroscopy, Fourier transmission infrared spectra (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The experiment showed that nearly 10 times of the usual amount of hydrate hydrazine as a reducing agent needed to be used, and the obtained TOMR-stabilized gold hydrosol had a higher level of stability at room temperature, which might be related to the structure of TOMR molecule and the formation of hydrophilic double layer structure of TOMR on the surface of gold core.