Cetyltrimethylammonium Chloride Research Articles

Cyclobis(paraquat-p-phenylene) – mediated electrosynthesis of new-type nanocomposite of palladium nanoparticles with designated macrocyclic organic compound

A new type nanocomposite of palladium nanoparticle (PdNP) with macrocyclic organic compound cyclobis(paraquat-p-phenylene) (CBPQT4+) was obtained by CBPQT4+- mediated electrosynthesis in the MeCN/ 0.05 М Bu4NPF6 and MeCN (50 vol%) – H2O/ 0.05 М Bu4NCl media. The nanocomposite has a pseudorotaxane structure formed due to the donor-acceptor binding of an electron-donor metal particle inside the cavity of an electron-acceptor CBPQT4+. Theoretical calculations have shown that up to 10 Pd atoms can fit into the CBPQT4+ cavity and the energy of such interaction is ∼500 kJ/mol in the gas phase. In addition to the target process, dispersion of the Pd-anode (current efficiency ∼ 170%) to form PdNPs in solution occurs in electrolyses in a diaphragmless cell. The resulting particles combine together with CBPQT4+to form aggregates, the size of which in solution is 80–900 nm. In the absence of stabilizer cetyltrimethylammonium chloride (CTAC), particles with an average size of PdNPs equal to 6.1 ± 1.8 nm and size of Pd crystallites of 4.1 – 8.2 nm are formed. The addition of CTAC leads to increased binding of PdNP with CBPQT4+and a decrease in the size of PdNPs and Pd crystallites (4.9 ± 2.9 nm, 3.0 – 5.9 nm, respectively). Nanocomposites obtained in a diaphragm electrolysis process contain PdNPs and Pd crystallites (3.2 ± 1.3 nm, 2.2 – 3.8 nm) of the smallest size. Binding with CBPQT4+causes slow activation and a decrease in the catalytic properties of PdNPs in the test reaction of p-nitrophenol reduction with sodium borohydride compared to larger PdNPs (5.9 ± 1.4 nm, Pd crystallite size is 2.9 – 5.6) obtained in the MV2+- mediated electrosynthesis under the same conditions.

Rapid Synthesis of Kaolinite Nanoscrolls through Microwave Processing.

Kaolinite nanoscrolls (NScs) are halloysite-like nanotubular structures of great interest due to their ability to superimpose halloysite’s properties and applicability. Especially attractive is the ability of these NScs to serve as reaction vessels for the uptake and conversion of different chemical species. The synthesis of kaolinite NScs, however, is demanding due to the various processing steps that lead to extended reaction times. Generally, three intercalation stages are involved in the synthesis, where the second step of methylation dominates others in terms of duration. The present research shows that introducing microwave processing throughout the various steps can simplify the procedure overall and reduce the synthesis period to less than a day (14 h). The kaolinite nanoscrolls were obtained using two final intercalating agents, aminopropyl trimethoxy silane (APTMS) and cetyltrimethylammonium chloride (CTAC). Both produce abundant NScs, as corroborated by microscopy measurements as well as the surface area of the final products; APTMS intercalated NScs were 63.34 m2/g, and CTAC intercalated NScs were 73.14 m2/g. The nanoscrolls averaged about 1 μm in length with outer diameters of APTMS and CTAC intercalated samples of 37.3 ± 8.8 nm and 24.9 ± 6.1 nm, respectively. The availability of methods for the rapid production of kaolinite nanoscrolls will lead to greater utility of these materials in technologically significant applications.

In Situ Assay of Interfacial Interaction between ZnO Nanoparticles and Live Cell Disturbed by Surfactants.

The interfacial interaction between pollutants and organisms is a critical process in controlling the environmental fates of pollutants; however, in situ assay of the interaction is still a great challenge. Here, in situ determination of dissociation constants (Kd) for ZnO nanoparticles (ZnO NPs) from live algal cells disturbed by different-charged surfactants was established using microscale thermophoresis (MST). Moreover, in situ measurement of the adhesion force between the ZnO NPs probe and live single cell was performed using an atomic force microscope (AFM). Results showed that the cationic cetyltrimethylammonium chloride (CTAC) and anionic sodium dodecylbenzenesulfonate (SDBS) increased but nonionic Triton X-100 (TX-100) decreased the adhesion of ZnO NPs on cells. However, the force signature exhibited a smooth single retracted peak at short distances in the SDBS- and TX-100-treated groups, distinguished from the "see-saw" pattern peak in the CTAC-treated groups. The extended Derjaguin-Landau-Verway-Overbeek (XDLVO) calculation further confirmed that SDBS and TX-100 mainly disturbed the short-range hydration on the NP-cell interface, while CTAC reduced the long-range electrostatic repulsion. Furthermore, an excellent linear correlation between Zn bioaccumulation and two parameters (Kd and adhesion force) indicated that NP-cell interfacial interactions affected Zn bioaccumulation. Thus, in situ assay provides a quantitative basis for the pollutant-organism interfacial interaction to evaluate the environmental fate and ecological risk of pollutants.

Development of a High Efficient Compound Surfactant for Foam Drainage in Gas Wells

In this study, the foaming properties of a compound surfactant formula containing cetyltrimethylammonium chloride (CTAC), cocamidopropyl betaine (CDAB), fatty alcohol polyoxyethylene ether-7 (AEO7) and sodium alpha-olefin sulfonate (AOST) were evaluated to meet the application requirements for foam generation and foam drainage in gas wells. The results exhibited that the foaming volume and the half-life of the compound surfactant solution (0.05 wt % CTAC + 0.7 wt % CDAB + 0.6 wt % AEO7 + 0.05 wt % AOST) can reach the values of 550 mL and 23 min, respectively, which suggested that the foaming ability and stability were improved in comparison with each solution containing a single surfactant. It showed that the surface tension can be lowered to 22.4 mN/m with the presence of the compound surfactants. Simultaneously, the microstructure of the foam was observed using a polarizing microscope, and it was found that there were almost no polyhedron structures in the foam within a certain range of formula concentrations. The results of the experiments also clarify that the formula has well properties of temperature resistance and salt resistance (measured using a high-speed agitator).

Tuning the structure and plasmonic properties of Pt–Au triangular nanoprisms: From deposition to etching

Because of the strong electromagnetic field at the corners and more tunable surface plasmon resonance (SPR) bands in the visible and infrared regions, gold triangular nanoprisms can be applied to more fields. Compared with monometallic nanomaterials, polymetallic nanomaterials are composed of multiple metals and possess many special optical properties. Recently, structurally novel Pt-based polymetallic nanostructures have attracted much attention due to their superior catalytic performance. In this study, gold triangular nanoprisms were prepared by the seed growth method. By adjusting the amount of seeds, gold triangular nanoprisms of different sizes were formed. By changing the concentration of Cetyltrimethylammonium Bromide (CTAB) and Cetyltrimethylammonium chloride (CTAC), the purification process of gold triangular nanoprisms was adjusted to make gold triangular nanoprisms more uniform. The synthesis of Pt-Au triangular nanoprisms and the switching between etching and deposition dominated in the reaction is controlled by adjusting the volume of AgNO3, H2PtCl6, and the size of gold triangular nanoprisms. At relatively high H2PtCl6 concentrations, the etching process dominates; at lower H2PtCl6 concentrations, the etching process is restrained. Due to the good catalytic performance of Pt itself and the rough surface-induced Surface-Enhanced Raman Scattering (SERS) improvement of the nanoparticles, the application of Pt-Au triangular nanoprisms in the fields of catalysis and SERS is proposed.

Application of noise reduction and heat insulation based on controlled-size polystyrene hollow microspheres

Core/shell polymer microspheres containing carboxyl group were prepared by emulsion polymerization, and then the hollow polymer microspheres (PHMs) were formed by infiltration and swelling after alkali solution post-treatment. Effects of emulsifier types and initial pH of alkali post-treatment on the particle size distribution and morphology of PHMs emulsion were investigated. Foamed animal skin material (FAS) was obtained by cross-linking and curing the skin collagen materials with PHMs. The results showed that the optimal initial pH was 9, and a stable PHMs emulsion with a maximum average particle size of 888.5 nm was obtained. The average particle size order of the PHMs emulsions obtained with different emulsifiers was: sodium stearate (1028.0 nm) > SDBS (823.6 nm) > cetyltrimethylammonium chloride (607.4 nm). The mechanical strength, porosity, and thermal stability of FAS were enhanced by PHMs dispersing and fixing, while its natural permeability and softness were retained. In addition, the whiteness and ultraviolet aging resistance of FAS were improved obviously. The thermal conductivity of FAS was reduced to 0.034 W/(K·m), which was in line with the standard of polystyrene foam board for building materials. In the range of 2000 ∼ 7000 Hz, the sound transmission loss of FAS reaches 25 ∼ 40 dB.

Development of fluorescent azapentalenes to study the reactivity of hypochlorous acid and chloramines in micellar systems

Hypochlorous acid (HClO) is an endogenous reactive oxygen species generated by the oxidation of chloride catalyzed by myeloperoxidase (MPO). This enzyme is abundant in polymorphonuclear cells and involved in the human innate immune function. This work presents the development of a fluorescent azapentalene (C1) able to be incorporated in micelles and susceptive to HClO due to its sulfide moiety. C1 is non-fluorescent in the aqueous medium but fluoresces when incorporated in micelles produced by surfactants such as sodium dodecyl sulfate (SDS), Triton X-100, and cetyltrimethylammonium chloride (CTAC). The addition of HClO promoted instantaneous fluorescence decay of C1 incorporated in SDS but not in Triton X-100 or CTAC, showing the higher accessibility of HClO to the SDS micelle core. The reactivity of C1 was also studied in the presence of amine compounds taurine, 4-aminobutanoic acid (GABA), and its ethyl ester (GABA-EE), leading to the formation of the respective chloramines. The reactivity increased with the GABA-EE, evidencing the higher accessibility to the micellar core due to the hydrophobic character of the ester derivative. The potentiality of the system to monitor the enzymatic production of HClO was demonstrated by using MPO and hydrogen peroxide (H2O2). Scavengers of HClO were applied to validate the method. In conclusion, applying C1 opens new possibilities for studying the biochemical properties of HClO and chloramines in micelles.

CTAB-assisted construction of 3D flower-sphere S-scheme Bi12O17Br2/Bi4O5Br2 heterojunction with enhanced visible-light photocatalytic performance

In this study, novel 3D flower-sphere S-scheme Bi12O17Br2/Bi4O5Br2 heterojunction was successfully synthesized at room temperature through a facile co-precipitation method. As the morphology controlling reagent and bromine resource, cetyltrimethylammonium bromide (CTAB) surfactant played significant roles in Bi12O17Br2/Bi4O5Br2 crystal growth and heterostructure construction. The BB-10 (Bi12O17Br2/Bi4O5Br2, pH = 10) heterojunction with hierarchical heterostructure presented excellent photocatalytic activity under visible light for antibiotic tetracycline (TC), malachite green (MG) and methyl violet (MV) removal and the photodegradation efficiency could reach 97.3%, 90.4% and 87.5%, respectively. In addition, when CTAB was replaced by cetyltrimethylammonium chloride (CTAC), the as-obtained 2D flower-like type-I BCB-10.5 (BiOCl/Bi4O5Cl2, pH = 10.5) heterojunction also exhibited outstanding visible-light photocatalytic activity for the removal of TC, MG and MV. Greatly enhanced photocatalytic activity owed to synergistic effects including unique hierarchical morphology, large specific surface area and suitable band structures. According to the active species trapping experiments, feasible photocatalytic mechanisms were proposed.

Remediation of nitrate contaminated groundwater using a simulated PRB system with an La–CTAC–modified biochar filler

In the present study, the Erigeron canadensis L., a typical invasive plant in Southwest China, was utilized as the raw material to prepare original biochar (ECL), a rare earth element La–modified biochar (La–ECL), and a rare earth element La coupling cationic surfactant [cetyltrimethylammonium chloride (CTAC)]–modified biochar (La/CTAC–ECL). These materials were then added to simulated permeable reactive barriers (PRBs) and their nitrate (NO3−) contaminant remediation performances were evaluated in groundwater. The results show that the breakthrough time for NO3− in a simulated PRB column increases as the concentration of the influent NO3− and the flow rate decreases, whereas with the increases of filler particle size and the height of the filler in the column initially increases, and then decreases. Considering an initial NO3− concentration of 50 mg L−1, and a filler particle size range of 0.8–1.2 mm, the maximum adsorption capacity of the La/CTAC–ECL column for NO3− is 18.99 mg g−1 for a filler column height of 10 cm and an influent flow rate of 15 ml min−1. The maximum quantity of adsorbed NO3− of 372.80 mg is obtained using a filler column height of 15 cm and an influent flow rate of 10 ml min−1. The Thomas and Yoon–Nelson models accurately predict the breakthrough of NO3− in groundwater in the simulated PRB column under different conditions, and the results are consistent with those from dynamic NO3− adsorption experiments. TEM, XRD, FTIR, and XPS analyses demonstrate that the modification using the La and CTAC improves the surface structure, porosity, permeability, and configuration of functional groups of the biochar. The mechanisms of NO3− removal from groundwater using the La/CTAC–ECL include pore filling, surface adsorption, ion exchange, and electrostatic adsorption. The composite La/CTAC–ECL exhibits a superior potential for the remediation of NO3− contaminated groundwater.

The preparation of high-yield uniform nanotubes from coal-measure kaolinite

A clean and efficient method was used to prepare kaolinite nanotubes from coal-measure kaolinite. Dimethyl sulfoxide, methanol, and cetyltrimethylammonium chloride were used to prepare intercalation compounds. We characterized the structures, surface functional group changes, morphology, and intercalation rates by x-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The intercalation rates of intercalation compounds of CK-D, CK-M, and CK-CTAC obtained from the x-ray diffraction (XRD) patterns reach 96.62%, 89.05%, and 86.96%, respectively. The morphology of the intercalation compounds of CK-D and CK-M did not change significantly before and after intercalation, showing a flaky accumulation similar to the original coal-measure kaolinite. Meanwhile, the macromolecular structure of the cetyltrimethylammonium chloride agent had a significant effect on the morphological changes of the kaolinite intercalation compounds. It can directly increase the basal spacing of coal-measure kaolinite from 7.15 Å to 38.38 Å, which is 5.36 times the original basal spacing. The energy input of the ultrasonic instrument can accelerate and enhance the exfoliation process of nanotube formation.

Simulation study of the mechanism of mesoscopic adsorption and the evolution of molecular dynamics of a surfactant/polymer composite on the surface of low rank coal

In this paper, the head group, tail group, and main chain of a single type of surfactant were constructed by a mesoscopic simulation, and the interaction between the simulated surfactant and coal dust both on its own and in a composite with polyacrylamide (PAM) was studied. The molecular adsorption behavior of cetyltrimethylammonium chloride (CTAC) surfactant mixed in different ratios with PAM was also experimentally characterized. The results showed that. From the above results, we can see that CTAC and PAM can form spherical, rod-shaped, and wormlike aggregates and a network structure as their volume fraction increases in an aqueous solution. The energy spectrum showed that when CTAC adsorbed on the surface of the coal, the content of carbon on the surface decreased from 63.8 to 50.4%, and the content of oxygen increased from 35.2 to 41.8%. The study on the adsorption mechanism of surfactants and polymers on the surface of low rank coal and the hydrophilicity of low rank coal is of great significance in developing efficient dust prevention technology for low rank coal to reduce coal dust pollution.

Tri-templating Synthesis of Multilevel Mesoporous Silica Microspheres with a Complex Interior Structure for Efficient CO2 Capture and Catalysis.

Multilevel porous architectures with microscopic shape control and tailor-made complex structures offer great potential for various innovative applications, but their elaborate design and synthesis have remained a scientific and technological challenge. Herein, we report a simple and effective tri-templating method, in which microscale Pickering droplets, nanoscale polystyrene colloids (PS), and molecular cetyltrimethylammonium chloride micelles are synchronously employed, for the fabrication of such micro-nanohierarchical mesoporous silica microspheres. In this protocol, Pickering droplet-directed interfacial sol-gel growth and its spatially confined surfactant assembly-directed sol-gel coating on PS suspensions are coupled together, enabling the successful formation of structured mesoporous silica that consists of numerous nanocompartments enclosed by a permeable shell. By varying the quantity of PS colloidal templates, rational regulation of the complex interior structure is achieved. Also, ascribed to the multilevel arrangement, this peculiar architecture not only shows desirable fast mass transport of external molecules but also possesses easy handling ability. After loading with tetraethylenepentamine or enzyme species, the yielded microspherical CO2 sorbents or immobilized biocatalysts, respectively, exhibit enhanced CO2 capture capacity and enzymatic catalysis efficiency. Notably, taking advantage of their microscopic characteristics, the immobilized biocatalysts could be ideally packed in a fixed-bed reactor for long-term continuous-flow enzymatic reactions. This tri-templating strategy provides a new synthetic route to access other multilevel microscopic materials with fascinating complex structures and paves a way to promote their practical applications.

The two-phase amphiphilic preconcentration based on surfactants to enrich phenolic compounds from diluted plant extracts and rat urine by micellar electrokinetic chromatography.

A novel technology by two-phase amphiphilic preconcentration based on surfactants was established for enriching phenolic compounds by micellar electrokinetic chromatography (MEKC). The cationic surfactant cetyltrimethylammonium chloride (CTAC) was combined with the anionic analytes that existed in the sample solution before injection. The boundary was formed between CTAC and sodium dodecyl sulfate (SDS) in the background solution when the sample solution was injected into the capillary, where the analytes bound inside micelles were released due to the stronger electrostatic force between SDS and CTAC. This procedure accelerated the separation of analytes from CTAC and greatly improved the enrichment efficiency. The optimal conditions were obtained after a series of optimizations, and the sensitivity enrichment factors of the four analytes were in the range of 39-93 compared to typical injections in capillary zone electrophoresis. Good linearity for matrix-matched calibrations was established for all analytes with R2 values of 0.9993-0.9997. The limits of detection (S/N=3) for kaempferol, quercetin, salvianolic acid C, and salvianolic acid B were 0.0166, 0.0292, 0.0215, and 0.0195µg/ml, respectively. The intracapillary RSDs of the analytes ranged from 0.8% to 1.3% for migration time and from 0.4% to 1.8% for peak areas. The developed method was successfully applied to the determination of phenolic compounds, the main compounds of Salvia miltiorrhiza Bge., and had been validated for the determination of spiked recoveries in rat urine.

Micellar interface modulation self-assembly strategy towards mesoporous bismuth oxychloride-based materials for boosting photocatalytic pharmaceuticals degradation

The spontaneous recombination of photogenerated carriers greatly limits the improvement of photocatalytic efficiency for bismuth oxychloride-based catalysts. Constructing porous or heterostructure photocatalysts can effectively inhibit their recombination. However, owing to the fast hydrolysis/condensation rates and uncontrollable nucleation/growth kinetics of Bi3+ species, it is difficult to achieve inorganic–organic co-assembly, and form mesoscopic structure and heterostructure. Herein, a series of mesoporous bismuth oxychloride-based materials (Bi2O3 at a stoichiometric ratio of 0 for Cl, Bi12O17Cl2, heterostructured Bi12O17Cl2/BiOCl and BiOCl) with various stoichiometry, tunable compositions and large surface areas are synthesized by a micellar interface modulation self-assembly strategy. In this strategy, Pluronic P123 and cetyltrimethyl ammonium chloride (CTAC) form P123/CTA+ composite micelles, which assemble with Bi3+ precursors by Coulomb interactions. Moreover, the Cl- ions are induced and modulated through composite micelles to involve in the slow hydrolysis and condensation of Bi3+ precursors at the hydrophilic-hydrophobic interface of composite micelles to form mesophase, thereby realizing the synthesis of mesoporous bismuth oxychloride with various stoichiometry and compositions by regulating CTAC amount. The prepared mesoporous Bi12O17Cl2/BiOCl-OV shows superior photocatalytic activity (degrade 83% within 30 min for 10 mg/L carbamazepine and 99% within 10 min for 10 mg/L ciprofloxacin), which can be ascribed to the mesoporous architecture, intimate contact heterojunction and abundant surface oxygen vacancies. This work provides a new idea and strategy for design and synthesis of high-efficiency mesoporous bismuth oxychloride-based photocatalysts.

Highly Curved, Quasi-Single-Crystalline Mesoporous Metal Nanoplates Promote CC Bond Cleavage in Ethanol Oxidation Electrocatalysis.

The ability to manipulate metal nanocrystals with well-defined morphologies and structures is greatly important in material chemistry, catalysis chemistry, nanoscience, and nanotechnology. Although 2D metals serve as interesting platforms, further manipulating them in solution with highly penetrated mesopores and ideal crystallinity remains a huge challenge. Here, an easy yet powerful synthesis strategy for manipulating the mesoporous structure and crystallinity of 2D metals in a controlled manner with cetyltrimethylammonium chloride as the mesopore-forming surfactant and extra iodine-ion as the structure/facet-selective agent is reported. This strategy allows for preparing an unprecedented type of 2D quasi-single-crystalline mesoporous nanoplates (SMPs) with highly curved morphology and controlled metal composition. The products, for example, PdCu SMPs, feature abundant undercoordinated sites, optimized electronic structures, excellent electron/mass transfers, and confined mesopore environments. Curved PdCu SMPs exhibit remarkable electrocatalytic activity of 6.09AmgPd -1 and stability for ethanol oxidation reaction (EOR) compared with its counterpart catalysts and commercial Pd/C. More importantly, PdCu SMPs are highly selective for EOR electrocatalysis that dramatically promotes C-C bond cleavage with a superior C1 pathway selectivity as high as 72.1%.

The effect and enhancement mechanism of hydrophobic interaction and electrostatic interaction on zwitterionic wormlike micelles

The effects of hydrophobic interaction and electrostatic interaction on the structure of zwitterionic wormlike micelles (WLMs) were studied. The change of the hydrocarbon chain length and addition of cetyl trimethyl ammonium chloride (CTAC) were employed to explore the effect of hydrophobic interaction and electrostatic interaction on the wormlike micelles constructed by zwitterionic viscoelastic surfactants and sodium p-toluene sulfonate (NaPts). The experimental results show that increasing hydrocarbon chain length of zwitterionic surfactant and the addition of CTAC can increase the viscoelasticity and zero-shear viscosity of the system. The calculated length of wormlike micelles also increases. This shows that the enhancement of hydrophobic interaction and electrostatic interaction can promote the growth and entanglement of wormlike micelles. In addition, scanning electron microscope (SEM) images confirmed that CTAC makes the connection between the zwitterionic micellar layer closer. This is undoubtedly beneficial to the growth of micellar structure. Finally, this work explores the enhancement mechanism of the hydrophobic interaction and electrostatic interaction on the micelle structure.

Synthesis of multi-branched Au nanocomposites with distinct plasmon resonance in NIR-II window and controlled CRISPR-Cas9 delivery for synergistic gene-photothermal therapy

Clinical implementation of photothermal therapy (PTT) is mainly hampered by limited tissue penetration, undesirable thermal damage to normal tissues, and thermotolerence induced by heat shock proteins (HSPs). To overcome these obstacles, we constructed a novel gene-photothermal synergistic therapeutic nanoplatform composed of a multi-branched Au nanooctopus (AuNO) core and mesoporous polydopamine (mPDA) shell, followed by CRISPR–Cas9 ribonucleoprotein (RNP) loading and then polyethylene glycol-folic acid (PEG-FA) coating. AuNO was simply synthesized by adjusting the ratio of cetyltrimethylammonium chloride (CTAC) and cetyltrimethylammonium bromide (CTAB), which showed significant localized surface plasmon resonances in the NIR-II window, and exhibited an excellent tissue penetration capability and high photothermal conversion efficiency (PCE, 47.68%). Even, the PCE could be further increased to 66.17% by mPDA coating. Furthermore, the sequential modification of AuNO@mPDA using RNP and PEG-FA can down-regulate HSP90α expression at tumor sites, enhance apoptosis and reduce the heat resistance of cancer cells. The synergistic effect of enhanced photothermal capacity and reduced thermoresistance addressed the multiple limitations of PTT, and presented excellent in vitro and in vivo antitumor efficacy, having great potential for the clinical application of PTT.

Mechanically robust, nanofibers-anchored small molecule hybrid plant protein materials with improved antibacterial activity

Soy protein isolate (SPI)-based nanocomposites are highly susceptible to degradation by microorganisms. To overcome this, this study explored the effects of incorporating curcumin into SPI-based nanocomposite films on the antimicrobial properties of the films. Cellulose nanofibril (CNF) was brushed with cetyltrimethylammonium chloride (CTAC) to prepare the modified drug-carrier system to better enable the binding of the lipophilic curcumin. Manifested by the strong hydrophobic interactions between curcumin and the CTAC molecules, curcumin was successfully loaded onto the modified CNF with encapsulation efficiency and loading amount of 97.79% and 9.78 mg/g, respectively. The curcumin hybrid film exhibited satisfactory antibacterial properties against E. coli and S. aureus due to the sustained release of curcumin, and they exhibited high antioxidant activities based on DPPH assays. The curcumin release rates were dependent on the solvent polarity; the release was faster in the 80% (v/v) and 50% (v/v) ethanol solutions than in the 20% (v/v) ethanol solution, and was diffusion-controlled. The oxidation of the CNF by sodium periodate before modification and loading resulted in the formation of dialdehyde groups that enabled Maillard reactions to occur with lysine residues of SPI peptides, which endowed films with desirable mechanical properties, including a maximum tensile strength of 11.86 MPa. This work broadened the research on the exploration of nanofiber-carrier systems for drug-loading/releasing to develop green composite films with strong antibacterial and mechanical properties.

Nanomaterial-Embedded DNA Films on 2D Frames.

Recently, 3D printing has provided opportunities for designing complex structures with ease. These printed structures can serve as molds for complex materials such as DNA and cetyltrimethylammonium chloride (CTMA)-modified DNA that have easily tunable functionalities via the embedding of various nanomaterials such as ions, nanoparticles, fluorophores, and proteins. Herein, we develop a simple and efficient method for constructing DNA flat and curved films containing water-soluble/thermochromatic dyes and di/trivalent ions and CTMA-modified DNA films embedded with organic light-emitting molecules (OLEM) with the aid of 2D/3D frames made by a 3D printer. We study the Raman spectra, current, and resistance of Cu2+-doped and Tb3+-doped DNA films and the photoluminescence of OLEM-embedded CTMA-modified DNA films to better understand the optoelectric characteristics of the samples. Compared to pristine DNA, ion-doped DNA films show noticeable variation of Raman peak intensities, which might be due to the interaction between the ion and phosphate backbone of DNA and the intercalation of ions in DNA base pairs. As expected, ion-doped DNA films show an increase of current with an increase in bias voltage. Because of the presence of metallic ions, DNA films with embedded ions showed relatively larger current than pristine DNA. The photoluminescent emission peaks of CTMA-modified DNA films with OLEMRed, OLEMGreen, and OLEMBlue were obtained at the wavelengths of 610, 515, and 469 nm, respectively. Finally, CIE color coordinates produced from CTMA-modified DNA films with different OLEM color types were plotted in color space. It may be feasible to produce multilayered DNA films as well. If so, multilayered DNA films embedded with different color dyes, ions, fluorescent materials, nanoparticles, proteins, and drug molecules could be used to realize multifunctional physical devices such as energy harvesting and chemo-bio sensors in the near future.

Design of silane-based UV-absorbing thin coatings on polyethylene films

UV-absorbing surfaces have received much attention and focus due to their relevance in a variety of research applications and industrial fields. However, these surfaces currently suffer from drawbacks such as instability due to leakage of the entrapped UV-absorbing compounds, complicated non-green synthetic processes, and/or lack of good optical properties. We propose a modified Stöber method where UV absorbing silane monomers containing the group2-hydroxy-4-(3-triethoxysilylpropoxy) diphenylketone (SiUV) in presence of the mesoporous producing surfactant cetyltrimethyl ammonium chloride (CTAC) was polymerized in an ethanol/water continuous phase under basic conditions. UV absorbing thin coatings onto polyethylene (PE) films were then spread with the former dispersion on corona-treated PE, followed by a thermal drying process. These films were highly UV absorbent and durable with excellent optical properties. Multiple applications of the UV absorbing coating were also tested and found to increase UV absorbance to approximately 100%, but on the other hand the optical properties were negatively affected. The coated samples underwent thermal shrinkage by 30% to simulate industrial applications. No significant change in UV absorbance and optical properties were discerned after their shrinkage. These results and synthetic simplicity indicate to the potential of the SiUV coated polymeric films to be used for industrial applications.