Octadecylamine Research Articles

The Effect of Functional Group Polarity in Palladium Immobilized Multiwalled Carbon Nanotube Catalysis: Application in Carbon-Carbon Coupling Reaction.

Carbon nanotubes (CNTs) are effective supports for nanometals and together they represent hybrids that combine the unique properties of both. A microwave-induced reaction was used to deposit nanopalladium on carboxylated and octadecylamine functionalized multiwall CNTs, which were used to carry out C-C coupling reactions in dimethylformamide (DMF) and toluene. These hybrids showed excellent catalytic activity with yield as high as 99.8%, while its enhancement with respect to commercially available Pd/C catalyst reached as high as 109%, and the reaction times were significantly lower. The polarity of the functionalized form was found to be a significant factor with the polar carboxylated CNT showing better activity in DMF while the relatively nonpolar octadecyl amine was better in toluene. The results suggest the possibility of tailor making functionalized CNTs when used as catalyst supports.

Synthesis and mechanism study of the highly monodispersed extra-small silver nanoparticles in reverse micelles

Silver nanoparticles (Ag NPs) play a significant role in catalysis, biosensor, antibacterial activity, SERS spectroscopy, and photoelectric materials. These prominent applications are strongly dependent on the size and uniformity of Ag NPs. However, a variety of preparation methods such as electrochemical and green synthesis methods are of difficulties to obtain extra-small and uniform Ag NPs due to complex growth environment, which is prone to render anisotropy of nanoparticles thereby limiting the development of Ag NPs. To address the unmet need, tremendous effort has been made synthesizing extra-small Ag NPs with the outstanding monodispersity and remarkable stability in reverse micelles. The efficient and facile method is established employing a high-performance protective agent, i.e., octadecylamine (ODA) with the average diameter of 3.36 ± 1.0 nm. Moreover, by adjusting octadecylamine concentration, the versatile method has the capability of controlling the size of Ag NPs precisely. In addition, the growth mechanism of Ag NPs based on nucleation theory is described schematically, which is of widespread generality to adapt our method for the preparation of other nanoparticles in the similar system. Overall, the promising strategy to the synthesis of extra-small Ag NPs lays a solid foundation for potential applications in wound healing, health care, medical diagnosis, and environmental remediation.

Studies on the secondary modification of SBS modified asphalt by the application of octadecyl amine grafted graphene nanoplatelets as modifier

Modified asphalt prepared via graphene nanoplatelets (GNPs) incorporation to styrene-butadiene-styrene (SBS) possesses enhanced high temperature performance and mechanical properties but the approach suffers from poor compatibility of the components. In this study, octadecyl amine (ODA) was grafted onto the surface of GNPs resulting in ODA-GNPs composite via covalent bonding method. GNPs and ODA-GNPs composites were applied as modifiers to SBS for modified asphalt preparation. Specific amount of ODA-GNPs incorporation improved ductility, softening point and penetration while DSR, MSCR and segregation experiment showed enhancement in viscoelastic, high temperature rutting resistance performance and compatibility of the SBS modified asphalt. Textural characterization of asphalt samples using FT-IR, XRD, SEM and AFM revealed the successful grafting of ODA onto GNPs surface resulting in increased interplanar spacing of GNPs. ODA grafted onto the surface of GNPs enhanced its lipophilicity in asphalt, leading to better particles dispersion. The present methodology using ODA-GNPs composite for the preparation of modified asphalt with enhanced mechanical properties, temperature resistance and viscosity, can be deemed as an efficient approach on industrial level applications.

Electrochemical sensor for detection of cancer cell based on folic acid and octadecylamine-functionalized graphene aerogel microspheres

Early diagnosis of cancers is critical for prevention of metastasis and early treatment. The study reports an electrochemical sensor for detection of cancer cell based on folic acid (FA) and octadecylamine (OA)-functionalized graphene aerogel microspheres (FA-GAM-OA). Citric acid was mixed with FA and OA and heated at 180 °C for 4 h to form FA and OA-functionalized graphene oxide. The graphene oxide was employed as solid particle surfactant for stabilizing toluene-in-water emulsion. The graphene oxide sheets in the emulsion were self-assembled into graphene oxide gel microspheres on the water/toluene interfaces. Followed by free drying and reduction in H2 at 400 °C for 5 h. The resulted FA-GAM-OA shows a sphere-like structure with an average diameter of 1.2 µm, the rich of open-pores and folic acid groups. Small particle size and good hydrophilicity make FA-GAM-OA can be dispersed in water for sensor preparation. The small size of graphene sheets and their self-assembly avoid a serious agglomeration of graphene sheets. The FA-GAM-OA offers a large surface area (1723.6 m2 g−1) and high electronic conductivity (2978.2 S m−1). The covalent linkage and ordered alignment of folic acid groups at FA-GAM-OA surface achieve to specific cancer cell capture with high capture efficiency. The electrochemical sensor based on FA-GAM-OA exhibits extremely good analytical performances in detection of liver cancer cells with a linear range of 5–105 cell mL−1 giving a low detection limit of 5 cells mL−1 (S/N = 3). The method was successfully applied to electrochemical detection of liver cancer cells in whole blood.

Molecular Structure and Decomposition Kinetics of Kaolinite/Alkylamine Intercalation Compounds.

Although the development of clay/polymer nanocomposites and their applications have attracted much attention in recent years, a thorough understanding of the structure and the decomposition mechanism of clay/polymer nanocomposites is still lacking. In this research, the intercalation of kaolinite (Kaol) with different alkylamines were investigated by X-ray diffracion (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetry and differential scanning calorimetry (TG-DSC). The results showed that the intercalation of Kaol/methanol compound with hexylamine (HA), dodecylamine (DA), and octadecylamine (OA) led to the expansion of the interlayer distance and resulted in the dominant basal diffraction at 2.86, 4.08, and 5.66 nm. The alky chains of HA, DA, and OA are tilted toward the Kaol surface in bilayer with an inclination angle of ~40°. The most probable mechanism function, activation energy E, and pre-exponential factor A were obtained by mutual authentication using KAS and Ozawa methods, itrative and Satava integral method. The average activation energy E of the three intercalation compounds are 104.44, 130.80, and 154.59 kJ mol−1, respectively. It shows a positive correlation with the alkyl chain length. The pre-exponential factor A was estimated to be 1.09 × 1015, 1.15 × 108, and 4.17 × 1021 s−1, respectively. The optimized mechanism function for the decomposition of alkylamine is G(α) = [(1-α) −1/3−1]2.

Tannic acid-assisted green fabrication of functionalized graphene towards its enhanced compatibility in NR nanocomposite

A green and efficient method has been developed to prepare functionalized graphene (NTGE) by liquid exfoliated graphene (TGE), using tannic acid (TA) as stabilizer, followed by further derivatization through the mild Mannich reaction between the phenolic hydroxyl groups on TA and octadecylamine (OC). Then the functionalized graphene (NTGE) was well compatible with organic polymer. The qualitative and quantitative analysis for NTGE was characterized by FTIR, UV–vis and TGA. The residual weight substantiated by TGA implies that the grafted OC content onto graphene is about 30%. The morphology of NTGE can be identified from the TEM micrographs and AFM which indicate TGE functionalized with OC increase interlayer spacing and decrease π-π interaction between TGE sheets. TGE sheets as fine as 1.8 nm and NTGE sheets with thickness of 2.1 nm were observed by AFM. A noticeable enhancement was achieved for NTGE compounded with NR systems. With the addition of 1 phr NTGE, tensile strength and tear strength of NTGE1@NR respectively increase 11.1% and 5.1% compared with TGE1@NR composite due to tight rubber-filler interactions. Nevertheless, the significant tensile strength and tear strength increase of 33% and 20% respectively for NTGE1@NR is obtained compared with Neat NR. This new preparation and functionalization route provides a choice for the large-scale application of functionalized graphene.

Ultrathin Copper Nanowire Synthesis with Tunable Morphology Using Organic Amines for Transparent Conductors

High-quality monodispersed copper nanowires with an ultrathin diameter of 13.5 nm, lengths up to 30 μm (aspect ratio >104) were successfully synthesized by a facile and controllable hydrothermal reduction procedure. The synthesis utilized glucose in the presence of hexadecylamine (HDA) and octadecylamine (ODA) as the capping agents. The copper decahedra nanoparticles with a low-surface-energy {111} plane formed pentatwinned one-dimensional nanowires, which was exactly verified by selected-area electron diffraction. Furthermore, the diameter and relative film conductivity of copper nanowires are sensitive to the HDA/ODA molar ratio. The conductor film made of the high-quality and ultrathin copper nanowires shows high transmittance and low resistance (83.83%, 61 Ω/□), exhibiting great potential in the applications of nanofabrication, transparent and flexible conductors, organic light-emitting diodes, and more.

Micellar effect of surfactant on the aggregation pattern of a fluorescent dye in ultra-thin film

This communication reports the effect of micelles on the molecular organisation of an anionic fluorescent dye Fluorescein Sodium salt (FSS) in Langmuir-Blodgett (LB) film. FSS forms non-fluorescent H-aggregates in LB film when interact with Cetyltrimethylammonium Bromide (CTAB) molecules below critical micellar concentration (CMC). While above CMC, LB films of FSS adsorbed on the micellar surface of CTAB, show predominant J-aggregated sites. Complex LB films of FSS are also prepared by allowing it to adsorb onto a preformed Langmuir monolayer of cationic amphiphile octadecylamine (ODA) at the air-water interface and then depositing it onto the solid substrate. Complex ODA-FSS LB films are also investigated and a comparison is made with the SA-CTAB-FSS complex films. Unlike SA-CTAB-FSS complex LB films, ODA-FSS LB films can not effectively control the non-fluorescent H-aggregated sites. The films are characterised by UV–vis absorption and fluorescence spectroscopic studies and in-situ Brewster Angle Microscopic (BAM) studies. Thus CTAB micelles play an important role to decrease the H-aggregated sites in the SA-CTAB-FSS complex LB films. This complex LB film can act as efficient fluorescence probe for several biological systems due to the absence of non-fluorescent H-aggregated sites.

Octadecyl Amine Functionalized Graphene Oxide towards Hydrophobic Chemical Resistant Epoxy Nanocomposites

AbstractIn this research study, graphene oxide (GO) was synthesized using an improved Hummers method and thence oxygen‐based functional groups were replaced with octadecyl amine. Afterwards, epoxy‐based nanocomposites containing GO and GO‐octadecyl amine (GO‐ODA) were fabricated via a vacuum shock technique. The chemical resistance of the fabricated nanocomposites against various solvents, namely xylene, toluene and distilled water, was investigated and the effect of chemical degradation on the hardness and structural stability of the nanocomposites was examined. Besides, SEM, contact angle and AFM analyses were conducted to evaluate morphology, hydrophobicity and roughness of the nanocomposites prior to and following the chemical degradation. The obtained results illustrated that the reinforcement of the epoxy‐based nanocomposites with GO‐ODA and GO, in order, enhanced chemical resistance, hardness, roughness, and hydrophobicity of the nanocomposites. For instance, after incorporating GO and GO‐ODA into the epoxy resin, the average roughness of the neat epoxy resin reduced 84.0% and 94.1%, the hardness of the neat epoxy resin increased from 80 to 82 and 86 kgf/mm2, and the contact angle of the epoxy resin changed from 76° to 71° and 85°, respectively. In brief, outcome of this study reveals that GO‐ODA can be used as an efficient filler to develop effective hydrophobic polymeric shields against chemical degradation.

Impedance analysis of film-forming amines for the corrosion protection of a carbon steel

Octadecylamine (ODA) is a well-known organic inhibitor for the corrosion protection of carbon steels. In the present study, electrochemical impedance data analysis was performed to extract physical parameters of the ODA thin film that formed on a P275 carbon steel surface. First, surface observations and contact angle measurements showed the steel surface modification after the ODA treatment linked to the adsorption of an organic hydrophobic thin film. X-ray photoelectron spectroscopy confirmed the presence of a very thin organic layer and revealed the presence of iron oxide/hydroxide underlying the ODA film. The impedance data analysis with a power-law distribution of resistivity in the organic film allowed the permittivity and thickness to be extracted. Finally, from the impedance results with and without ODA, the instantaneous corrosion inhibition efficiency was determined.

Effects of octadecylamine functionalization of carbon nanotubes on dispersion, polarity, and mechanical properties of CNT/HDPE nanocomposites

Homogeneous dispersion of carbon nanotubes (CNTs) in polymers has significantly improved their processing and application as nanomaterials. Generally, CNTs tend to agglomerate due to their high aspect ratios and strong van der Waals interaction. Surface functionalization appears to be a solution to this problem. This study presents a controlled dispersion of carbon nanotubes in polyethylene through surface modification using a mixture of concentrated acid and octadecylamine (ODA). CNTs were characterized by Fourier transform infrared, Raman and X-ray photoelectron spectroscopy, and transmission electron microscopy. The results confirmed that carboxyl and alkane groups were successfully introduced on CNT surfaces. The acid- and amine-functionalized carbon nanotubes were dispersed in four solvents with different polarities (water, ethanol, acetone, and xylene) to correlate the degree of dispersion of CNT with their polarity. The results showed that CNT dispersion stability strongly depends on solvent and carbon nanotube polarities after the functionalization step. The nanohardness and tensile tests showed that the addition of CNTs, especially the functionalized with ODA, leaded the polymer harder, increasing its Young’s modulus and tensile strength. However, its toughness and deformation capacity were reduced. The potential applications of CNT-based polymer nanocomposites broaden considerably due to the surface engineering of carbon nanotubes.

Ag-carried CMC/functional copolymer/ODA-Mt wLED-treated NC and their responses to brain cancer cells

The subject of this work is synthesis and characterization of novel multifunctional nanocomposite (8/2A-NC) consisting (1) carboxymethyl cellulose (CMC) as a matrix biopolymer and poly (maleic acid-alt-acrylic acid) as a reactive synthetic partner matrix polymer; (2) octadecyl amine montmorillonite (ODA-MMT) reactive organoclay provide intercalated silicate layers structures and aqueous colloidal dispersing medium, and MMT as carriers and targeting agents for anticancer agents in drug delivery systems, respectively. ODA as a intercalated surfactant finely dispersed 8/2A NC and its compatibility with matrix polymers via the interfacial polarization (complexing) and functionalization of matrix polymers by amine (ODA) and carboxylic acids from both the CMC and copolymer; (3) silver nanoparticles (AgNPs) as in-situ generated onto matrix polymers with unique nano-size and morphology parameters was synthesized. Important material science and bioengineering aspects of these investigations included (a) novel approach in synthetic pathways; (b) effects of physical and chemical structural rearrangements; (c) effects of Light Emitting Dioda (LED)-treatment on the FT-IR spectra, XRD reflection parameters, SEM-TEM morphology and nano-size and diameter distribution of AgNPs onto matrix polymers; (d) positive effect of LED-treatment of 8/2A nanocomposite and its response to the MIAPaCa-2 and U87 human brain cancer cell lines were evaluated. Novel 8/2A-NC multifunctional drug consisting unique positive, intercalating and encapsulated core-shell morphology structures, nano-size (5.6 nm) and narrow diameter distribution (94%) of AgNPs onto matrix polymers [silver NPs (0.25%) in 8/2A NC (25%)] with highest volume of contact area compared with used cancer micro-cells show lowest cell viability as an excellent anticancer platform. 8/2A-NC is a novel multifunctional drug with intercalating and encapsulated core-shell morphology structures consisting of positively charged, non-randomly distributed AgNPs with a large contact area and low diameters (5–6 nm). The anticancer properties of (This factor is not conformed experimentally in work) this drug can be explained by the following structural factors: 8/2A-NC contains a combination of active sites from protonated hydroxyl, carboxyl and amine groups; Ag+-cations and ODA-MMT with high physical and chemical surface areas. We suggest this material be further explored for anti-cancer testing.

Impeded physical aging in PIM-1 membranes containing graphene-like fillers

Physical aging of polymer of intrinsic microporosity PIM-1 is one of the major obstacles for its application as a commercial membrane material for gas separation. In this work, physical aging of PIM-1 and matrices of this same polymer containing graphene-like materials were studied. Graphene-like fillers resulted from the functionalization of graphene oxide (GO) with two alkyl chains of different lengths, using octylamine (OA) and octadecylamine (ODA), and further chemical reduction. Extents of membrane aging were evaluated through changes in gas permeability over time; the separation of gas mixtures comprising carbon dioxide and methane, which are of great interest for industrial applications such as the production of biogas or the purification of natural gas, was carried out. 50:50 vol% CO2/CH4 mixtures were used as feed and separation performance analysed for fresh membranes and at intervals of approximately a month up to 155 days. At the end of this testing period, aged PIM-1 membranes showed a CO2 permeability of (2.0 ± 0.7) × 103 Barrer, which corresponds to a CO2 permeability reduction of 68% from the value obtained right after their fabrication. The addition of alkyl-functionalized GO is shown to be an efficient strategy to retard the physical aging of PIM-1 membranes; filler loadings as low as 0.05 wt% of reduced octyl-functionalized GO showed a CO2 permeability of (3.5 ± 0.6) × 103 Barrer after 5 months, which is almost three quarters higher than that of pure PIM-1 membrane aged for the same time period and represents a reduction of just 39% from its initial value. Moreover, the addition of graphene-like materials to PIM-1 does not affect its mechanical properties.

Poly(2-carboxyethyl acrylate-co-ethylene glycol dimethacrylate) precursor monolith. Part I. Carbodiimide assisted post-polymerization modification with octadecyl ligands for use in reversed phase capillary liquid chromatography

In this proof of concept study, a new precursor monolithic column was prepared by the in situ co-polymerization of 2-carboxyethyl acrylate (CEA) and ethylene glycol dimethacrylate (EDMA) in a 300 μm i.d. fused silica capillary yielding a poly(CEA-co-EDMA) monolithic column. This carboxy monolith precursor with its surface carboxyl groups was subsequently subjected to post-polymerization modification with octadecylamine (ODA) via a carbodiimide conjugation reaction. The carbodiimide with its zero-length carboxyl-to-amine coupling ability works by activating the surface carboxyl groups of the monolith for direct reaction with the primary amines of ODA via amide bond formation. This reaction, which is applied for the first time in monolithic column fabrication, yielded the octadecyl-poly(CEA-co-EDMA) monolithic capillary column for use in reversed phase capillary LC. This octadecyl column was evaluated for its RPC retention property with alkylbenzenes (ABs) and alkyl phenyl ketones (APKs). The methylene group selectivity (αCH2) in the particular homologs was about the same for both ABs and APKs (αCH2 = 1.6) using the same mobile phase composition. This may indicate that the retention mechanism is the same for both homologous series. The retention behaviors of polyaromatic hydrocarbons and chlorophenol compounds were also examined on the octadecyl capillary column.

Mussel Adhesive-Inspired Design of Superhydrophobic Nanofibrillated Cellulose Aerogels for Oil/Water Separation

Inspiration from biomimetics—the chemistry of mussel adhesives—was taken for imparting superhydrophobic properties to nanofibrillated cellulose (NFC) matrices. A polydopamine (PDA) surface coating was introduced, acting as an anchor between the NFC scaffold and octadecylamine (ODA): PDA is coated onto the NFC scaffolds by its adhesive properties and the ODA is successfully attached to the PDA by a Schiff base reaction. The ultralow density of 6.04 mg/cm3 combined with the high contact angle of 152.5° endows the composite aerogel with superb buoyancy and excellent oil/water separation selectivity. Oil can be rapidly absorbed from a mixture of oil and water. In addition, the modified aerogel can take up a wide range of organic solvents, with the maximum absorption capacity reaching up to 176 g/g, depending on the density of the liquids. The novel superhydrophobic aerogel shows great potential as an adsorber for oil and solvent spills and as an oil–water separator.

Enamine Approach for Versatile and Reversible Functionalization on Cellulose Related Porous Sponges

A readily modifiable cellulose sponge was prepared from cellulose acetoacetate (CAA). Facile postsynthetic modification with primary amino-containing modifiers such as octadecyl amine (ODA), cysteine (CYS), and l-glutamic acid (GLU) could be achieved demonstrating the ease of anchoring a broad selection of functional groups to the surface of the sponges. This postsynthetic modification process was systematically characterized by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, which confirmed the formation of the enamine bonds. Besides, the microstructures and mechanical properties of the sponges were well preserved throughout the postsynthetic modification process. The enamine bonds, as one of the dynamic covalent bonds, were easily formed under mild and neutral conditions and broken under exposure to a low pH stimulus. The enamine bonds were used to modify the CAA sponges, which can achieve the versatility and recycling of cellulose porous materials. Therefore, the resulting...

PH-Responsive Mercaptoundecanoic Acid Functionalized Gold Nanoparticles and Applications in Catalysis.

Mercaptoundecanoic acid (MUA) functionalized gold nanoparticles (AuNP-MUA) were synthesized and demonstrated to possess pH-triggered aggregation and re-dispersion, as well as the capability of phase transfer between aqueous and organic phases in response to changes in pH. The pH of aggregation for AuNP-MUA is consistent with the pKa of MUA (pH ~4) in solution, while AuNP-MUA phase transition between aqueous and organic phases occurs at pH ~9. The ion pair formation between the amine group in octadecylamine (ODA), the carboxylate group in MUA, and the hydrophobic alkyl chain of ODA facilitates the phase transfer of AuNP-MUA into an organic medium. The AuNP-MUA were investigated as a reusable catalyst in the catalytic reduction of 4-nitrophenol by borohydride—a model reaction for AuNPs. It was determined that 100% MUA surface coverage completely inhibits the catalytic activity of AuNPs. Decreasing the surface coverage was shown to increase catalytic activity, but this decrease also leads to decreased colloidal stability, recoverability, and reusability in subsequent reactions. At 60% MUA surface coverage, colloidal stability and catalytic activity were achieved, but the surface coverage was insufficient to enable redispersion following pH-induced recovery. A balance between AuNP colloidal stability, recoverability, and catalytic activity with reusability was achieved at 90% MUA surface coverage. The AuNP-MUA catalyst can also be recovered at different pH ranges depending on the recovery method employed. At pH ~4, protonation of the MUA results in reduced surface charge and aggregation. At pH ~9, ODA will form an ion-pair with the MUA and induce phase transfer into an immiscible organic phase. Both the pH-triggered aggregation/re-dispersion and aqueous/organic phase transfer methods were employed for catalyst recovery and reuse in subsequent reactions. The ability to recover and reuse the AuNP-MUA catalyst by two different methods and different pH regimes is significant, based on the fact that nanoparticle-catalyzed reactions may occur under different pH conditions.

The effects of octadecylamine functionalized multi-wall carbon nanotubes on the conductive and mechanical properties of ultra-high molecular weight polyethylene

Multi-wall carbon nanotubes (MWCNTs) are usually used as conductive fillers to improve the conductive and mechanical properties of ultra-high molecular weight polyethylene (UHMWPE) simultaneously. But the poor dispersion of MWCNTs in UHMWPE and the weak compatibility between MWCNTs and UHMWPE lead to lots of defect sites and limit the efficiency of load transfer between UHMWPE and MWCNTs. To solve these problems, octadecylamine (ODA) functionalized MWCNTs (MWCNT-ODA) were prepared and its effects on the conductive and mechanical properties of UHMWPE were investigated. The X-ray photoelectron spectrometer (XPS) measurements indicated that ODA was successfully grafted on the surface of MWCNTs. The electrical conductivity tests showed that 0.5 wt% addition of MWCNT-ODA can obviously reduce the volume resistivity of UHMWPE composites by 12 orders of magnitude compared to pure UHMWPE. Meanwhile, its impact strength achieved an increase of about 42.1% and the tensile strength was slightly improved from 33.5 MPa to 40.7 MPa compared with that of UHMWPE. The microstructure features of the impact fracture surfaces were analyzed by field emission scanning electron microscope (SEM). This result revealed the existence of a stronger interfacial force between the UHMWPE and MWCNT-ODA, which is responsible for the improvement of mechanical properties of UHMWPE.

Formation and characterization of one-dimensional ZnS nanowires for ZnS/P3HT hybrid polymer solar cells with improved efficiency

Photovoltaic performance of hybrid devices consisting of zinc sulphide (ZnS) one-dimensional (1D) nanowires and P3HT polymer was studied. As we previously reported, hybrid solar cell architecture based on ZnS, where open circuit voltage reaches high value, deserves special attention. In this work, compared to our previous research, zero-dimensional (0D) ZnS nanoparticles were replaced by one-dimensional (1D) ZnS nanowires synthesized simply with a hot injection method. In order to improve the charge transport in hybrid solar cells, additionally, the initial ligand of octadecylamine (ODA) was partially replaced by the o-phenylenediamine. The as-synthesized products were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis spectroscopy, photoluminescence (PL) spectroscopy, energy dispersive spectroscopy (EDS), Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. The performance of the devices significantly depended on the concentration of one-dimensional ZnS nanowires incorporated in the active layer (optimal 10 wt.%) and their morphology. In the presented work, we showed that devices based on 1D ZnS nanowires were distinguished by the high value of Voc parameter (with the maximum achieved value of 0.634 V). Also we investigated the spatial layout of nanocrystals in the device, depending on its post treatment, using atomic force microscopy (AFM), time-of-flight secondary ion mass spectrometry (TOF-SIMS) and ultraviolet photoelectron spectroscopy (UPS). Our study showed spatial segregation of nanocrystals to both interfaces with electrodes, and also we showed significant changes (0.71 eV at the top) in the PEDOT:PSS work function after mixing with ZnS nanocrystals, which resulted in an increase in the difference in contact potential at respective electrodes, which explained the high value of Voc. In comparison to our previous study, by replacing an active layer of the 0D ZnS nanocrystals with 1D ZnS nanowires, nearly a triple increase of the overall efficiency (maximum of % η of 0.568) of the device was observed.

Insights into the inhibition mechanism of a novel supramolecular complex towards the corrosion of mild steel in the condensate water: experimental and theoretical studies

A supramolecular complex (HPDA) based on (2-hydroxypropyl)-β-cyclodextrin (HP-β-CD) and octadecylamine (ODA) exhibited a favourable inhibiting effect on the corrosion of mild steel (MS) in the condensate water. The structural properties of HPDA, including the apparent association constant (κ) and the optimal spatial configuration, were clarified using phase solubility simulation and molecular mechanics calculations. The results indicated that HPDA was fairly stable in water with a κ value of 9199 mol−1, and its four possible configurations might coexist. The corrosion inhibition effect of HPDA was collectively evaluated by both experimental and theoretical methods. Weight loss measurements showed that the inhibition efficiency of HPDA depended on the concentration and temperature, and the maximum value could reach 92.6% with 50 mg L−1 concentration at 313 K. The potentiodynamic polarization tests showed that HPDA was a mixed type inhibitor with a predominantly anodic type. Also, the polarization resistance was effectively enhanced in the presence of HPDA according to the results of electrochemical impedance spectroscopy. Adsorption experiments revealed that HPDA inhibited the corrosion of MS by a chemisorption mechanism, which was well described by the Langmuir model. Surface analyses based on X-ray photoelectron spectroscopy and Auger electron spectroscopy disclosed that the chemisorption of HPDA on the MS surface resulted from the self-assembly of guest molecules (ODA) with a tilted orientation. In addition, an apparent connection was ascertained between the adsorption measurements and the theoretical parameters (Mulliken charges and molecular electrostatic potential plot) using quantum chemical calculations.