A structural and corrosion study of triethoxysilyl functionalized POSS coatings on AA 2024 alloy

Self-propelled micro/nanobots: A new insight into precisely targeting cancerous cells through intelligent and deep cancer penetration

Cancer overlooks are globally one of the most dangerous and life-threatening tribulations. While significant advances have been made in the targeted delivery of anti-cancer medications over the last few years, several challenges, such as low efficacy and strong toxic effects, remain to be addressed. Micro/nanomotors have been thoroughly studied for both effective cancer detection and treatment, as demonstrated by significant advancements in the architecture of smart and functional micro/nanomotor biomedical systems. Able to self-propelled within fluid media, micro/nanomotors have attractive vehicles to maximize the efficacy of tumor delivery. Here, we present the current developments in the delivery, detection, and imaging-guided treatment of micro/nanomotors in the clinical field, including cancer-related specific targeted drug delivery, and then discuss the barriers and difficulties encountered by micro/nanomotors throughout the medical process. Furthermore, this paper addresses the potential growth of micro/nanomotors for medical applications, and sets out the current drawbacks and future research directions for more advancement.

Evaluation of Tannins as Potential Green Corrosion Inhibitors of Aluminium Alloy Used in Aeronautical Industry

In this work some organic natural products were studied, namely tannic acid, gallic acid, mimosa tannin and chestnut tannin, as potential green corrosion inhibitors of the aluminium alloy AA2024-T3. The anodizing treatment was performed in a solution of the referred organic compounds in diluted sulfuric acid. The electrochemical impedance spectroscopy and the potentiodynamic polarization were performed to assess sealing quality and corrosion protection granted by the anodic films. To understand the green inhibitors; interaction with the metal surface, FTIR spectra of anodizing and anodizing and sealed samples of AA2023-T3 were recorded, and the shifts in the position of the major bands confirmed that the green inhibitor interacts with the metal surface. Images of the morphology of the coatings were provided by Scanning Electron Microscopy. From the results obtained through the various techniques that were used to carry out this study it is possible to conclude that the formed anodic films can be a good contribution for the prevention of corrosion in the aluminium alloy AA2024-T3.

Carbon Dots as Environment-Friendly and Efficient Corrosion Inhibitors for Q235 Steel in 1 M HCl

To reduce the corrosion of Q235 steel, environment-friendly and efficient N-doped carbon dots (N-CDs) were synthesized using 4-amino salicylic acid (4-ASA) and l-histidine (l-His) as precursors. The corrosion inhibition behavior of N-CDs for Q235 steel in 1 M HCl solution was systematically investigated using a weight-loss experiment, an electrochemical test, and corrosion morphology. Results showed that N-CDs could effectively inhibit the corrosion of Q235 steel, and the inhibitory efficiency reached 93% at 50 mg L^-1. Quantum chemistry and molecular dynamics were used to study the inhibition mechanism of N-CDs. The results demonstrated that N-CDs exhibited a strong adsorption force on metal and the adsorption process followed the Langmuir adsorption isotherm, indicating physical/chemical mixed adsorption.

Oxidized Titanium Tungsten Surface Functionalization by Silane-, Phosphonic Acid-, or Ortho-dihydroxyaryl-Based Organolayers

Titanium tungsten (TiW) films (200 nm thick) were cleaned by oxygen plasma, and the resulting oxidized surfaces were functionalized by 3-aminopropylphosphonic acid (APPA), 3-ethoxydimethylsilylpropylamine (APDMES), or dopamine (DA) to form three different organolayers. The three resulting organolayers were characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, and Fourier transform infrared spectroscopy analyses. The stability of each organolayer was investigated. Our results suggested that the Si-O-Ti or Si-O-W bonds formed by the reactions of APDMES with surface-oxidized TiW were rather labile, whereas the catechol layer was less labile. The APPA layer was the most stable of all tested surface modifications.

Close contacts at the interface: Experimental-computational synergies for solving complexity problems

The study of material science has been long devoted to the disentanglement of bulk structures which mainly entails finding the inner structure of materials. That structure is accountable for a major portion of materials’ properties. Yet, as our knowledge of these “backbones” enlarged so did the interest for the materials’ boundaries properties which means the properties at the frontier with the surrounding environment that is called interface. The interface is thus to be understood as the sum of the material’s surface plus the surrounding environment be it in solid, liquid or gas phase. The study of phenomena at this interface requires both the use of experimental and theoretical techniques and, above all, a wise combination of them in order to shed light over the most intimate details at atomic, molecular and mesostructure levels. Here, we report several cases to be used as proof of concept of the results achieved when studying interface phenomena by combining a myriad of experimental and theoretical tools to overcome the usual limitation regardind  atomic detail, size and time scales and systems of complex composition. Real world examples of the combined experimental-theoretical work and new tools, software, is offered to the readers.

POSS-ProDOT Crosslinking of PEDOT

Alkoxy-functionalized polythiophenes such as poly(3,4-ethylenedioxythiophene) (PEDOT) and poly(3,4-propylenedioxythiophene) (PProDOT) have become promising materials for a variety of applications including bioelectronic devices due to their high conductivity, relatively soft mechanical response, good chemical stability and excellent biocompatibility. However the long-term applications of PEDOT and PProDOT coatings are still limited by their relatively poor electrochemical stability on various inorganic substrates. Here, we report the synthesis of an octa-ProDOT-functionalized polyhedral oligomeric silsesquioxane (POSS) derivative (POSS-ProDOT) and its copolymerization with EDOT to improve the stability of PEDOT coatings. The POSS-ProDOT crosslinker was synthesized via thiol-ene "click" chemistry, and its structure was confirmed by both Nuclear Magnetic Resonance and Fourier Transform Infrared spectroscopies. PEDOT copolymer films were then electrochemically deposited with various concentrations of the crosslinker. The resulting PEDOT-co-POSS-ProDOT copolymer films were characterized by Cyclic Voltammetry, Electrochemical Impedance Spectroscopy, Ultraviolet-Visible spectroscopy and Scanning Electron Microscopy. The optical, morphological and electrochemical properties of the copolymer films could be systematically tuned with the incorporation of POSS-ProDOT. Significantly enhanced electrochemical stability of the copolymers was observed at intermediate levels of POSS-ProDOT content (3.1 wt%). It is expected that these highly stable PEDOT-co-POSS-ProDOT materials will be excellent candidates for use in bioelectronics devices such as neural electrodes.

New Water Vapor Barrier Film Based on Lamellar Aliphatic-Monoamine-Bridged Polysilsesquioxane

Siloxane-based hybrid lamellar materials with ordered nanostructure units paralleling to the substrate have been widely used for water vapor barrier. However, it is very difficult to control the orientation of the lamellar units at molecular level. In this Research Article, a new lamellar bridged polysilsesquioxane (BPSQ) film, whose voids between lamellae were filled by pendant alkyl chains in the organic bridge, was prepared via the stoichiometric reaction between 3-glycidoxypropyltrimethoxysilane and aliphatic monoamine at 60 °C without catalyst. Experimental evidence obtained from FT-IR, MS, NMR, and GIXRD techniques suggested that the as-prepared BPSQ films were constructed by lamellar units with disordered orientation. Nonetheless, they possessed satisfactory water vapor barrier performance for potassium dihydrogen phosphate (KDP) and deuterated potassium dihydrogen phosphate (DKDP) optical crystals, and the water vapor transmission rate through BPSQ film with thickness of 25 μm was as low as 20.3 g·m(-2)·d(-1). Those results proved that filling the voids between molecular lamellae with alkyl chains greatly weakened the effect of lamellar unit orientation on the vapor barrier property of BPSQ film.

Lanthanide complex-functionalized polyhedral oligomeric silsesquioxane with multicolor emission covered from 450 nm to 1700 nm

Six new hybrid materials covalently linking ternary lanthanide complexes to POSS were prepared, and the luminescent properties were investigated in detail.

Surface with antimicrobial activity obtained through silane coating with covalently bound polymyxin B

Surfaces exhibiting antimicrobial activity were prepared for potential medical application. A polycationic lipopeptide polymyxin B was selected as the bioactive agent for covalent immobilization onto the surface. First, by using sol-gel technology the inert glass substrate was functionalized by a silane coating with epoxide rings to which the peptide was coupled by means of a catalyst. Preparation of the coating and presence of the peptide on the surface were followed by FTIR, XPS and AFM analyses. The obtained material showed antimicrobial effect indicating that in spite of immobilization the peptide has retained its bioactivity. The coated surface was able to reduce bacterial cell counts of the Gram-negative bacterium Escherichia coli by more than five orders of magnitude in 24 h of incubation. It can be concluded that bioactive coatings with covalently bound polycationic peptides have potential for application on medical devices where leakage into the surrounding is not allowed in order to prevent bacterial growth and biofilm formation.

Synthesis of polyhedral phenylsilsesquioxanes with KF as the source of the fluoride ion

An alternative method for the preparation of polyhedral phenylsilsesquioxanes is reported. Phenylsilsesquioxane resin and freshly hydrolysed phenyltrimethoxysilane was refluxed with various phase-transfer catalysts and potassium fluoride in toluene yielding octaphenylsilsesquioxane, or in a mixture of THF and ethanol yielding dodecaphenylsilsesquioxane.