Hyperbranched Kaustamin as an antibacterial for surface treatment

Hyperbranched Kaustamin as a commercially available cationic flocculant adsorbs on a glass surface with formation of the polymer film. Kaustamin has antimicrobial effect on Gram-negative and Gram-positive bacteria, its film on glass keeps integrity and shape after absorption of water from air, which make the polymer appropriate as an antibacterial cover.     

Composite Likelihood Inference in a Discrete Latent Variable Model for Two-Way “Clustering-by-Segmentation” Problems

We consider a discrete latent variable model for two-way data arrays, which allows one to simultaneously produce clusters along one of the data dimensions (e.g., exchangeable observational units or features) and contiguous groups, or segments, along the other (e.g., consecutively ordered times or locations). The model relies on a hidden Markov structure but, given its complexity, cannot be estimated by full maximum likelihood. Therefore, we introduce a composite likelihood methodology based on considering different subsets of the data. The proposed approach is illustrated by simulation, and with an application to genomic data.     

Controlled evaporative self-assembly of polymer nanoribbons using oscillating capillary bridges

Evaporative self-assembly (ESA), based on the “coffee-ring” effect, is a versatile technique for assembling particle solutions into mesoscale patterns and structures on different substrates. ESA works with a wide variety of organic and inorganic materials, where the solution is a combination of volatile solvent and nonvolatile solute. Modified ESA methods, such as “stop-and-go flow coating,” use a programmed meniscus “stick–slip” motion to create mesoscale assemblies with controlled shape, size, and architecture. However, current methods are not scalable for increased production volumes or patterning large surface areas. We demonstrate a new ESA method, where an oscillating blade controls the meniscus depinning and drives the evaporative assembly of solutes at the pinned meniscus. Results show that oscillation frequency and substrate speed control time/distance intervals between successive meniscus depinning, and the assembly dimensions depend on solution concentration, oscillation frequency, substrate speed, and meniscus height. We report the mechanism of the meniscus depinning and the control over assembly cross-sectional dimensions. This advance provides a scalable ESA method with faster processing times and maintained advantages. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 1545–1551     

Effects of silica nanoparticle addition on polymer semiconductor wettability and carrier mobility in solution‐processable organic transistors on hydrophobic substrates

The effects of the addition of silica nanoparticles (SNPs) on wettability of regioregular poly(3‐hexylthiophene) (P3HT) organic semiconductor solutions on hydrophobic substrates and the carrier mobility in organic field‐effect transistors (OFETs) made of these films are investigated. The dewetting of films made from P3HT solutions on hydrophobic substrates modified with octadecyltrichlorosilane (ODTS) is markedly suppressed after the addition of SNPs with phenyl surfactants. This enables us to fabricate continuous P3HT/SNPs films with high crystallinity by the conventional spin‐coating technique, leading to higher mobility compared with P3HT FETs fabricated on non‐modified substrates. Moreover, the addition of SNPs with larger diameters compensates for the degradation of mobility associated with the increase in the concentration of SNPs. Solution‐processed P3HT/SNPs FETs on ODTS‐modified substrates exhibit a field‐effect mobility of 1.3 × 10^?2 cm² V^?1 s^?1, which is almost comparable to that of P3HT FETs without SNPs (2.1 × 10^?2 cm² V^?1 s^?1). © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 509–516     

A novel method for serum lipoprotein profiling using high performance capillary isotachophoresis

A new capillary isotachophoresis (cITP) method for lipoprotein profiling with superior lipoprotein coverage compared to previous methods has been developed, resolving twice as many lipoprotein species (18 peaks/fractions) in serum or plasma in less than 9.5 min. For this, a novel mixture of 24 spacers, including amino acids, dipeptides and sulfonic acids, was developed and fine-tuned, using predictive software (PeakMaster) and testing of spiked serum samples. Lipoprotein peaks were identified by serum-spiking with reference lipoproteins. Compatibility with common lipophilic stains for selective lipoprotein detection with either UV/Vis or laser-induced fluorescence was demonstrated. A special new capillary with a neutral coating (combining water-compatible OV1701-OH deactivation and methylation) was used for the first time for electrodriven separations, allowing very stable separations in a pH 8.8–9.4 gradient system, being functional for more than 100 injections. Excellent reproducibility was achieved, with coefficients of variation lower than 2.6% for absolute migration times. Comparison was performed with human plasma samples analyzed by NMR, leading to similar results with cITP after multivariate statistics, regarding group-clustering and lipoprotein species correlation. The new cITP method was applied to the analysis of serum samples from a LDL receptor knock-out mice model fed either a normal diet or a western-type diet. Differences in the lipoprotein levels and in the sublipoprotein types were detected, showing a shift to more atherogenic particles due to the high cholesterol diet. In summary, this novel method will allow more detailed and informative profiling of lipoprotein particle subtypes for cardiovascular disease research.     

Structural, optical and electromagnetic properties of aluminum-clay nanocomposites

Aluminum pillared and exchanged bentonite particles were synthesized by the ion exchange method. The characteristics of the particles were investigated by Fourier-transform infrared spectra (FTIR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscope (SEM), electron dispersive X-ray spectrometer (EDS), reflectance spectrophotometer (RS) and electromagnetic transition instrument (ETI). FTIR spectra showed a successful incorporation of Al complexes into the clay interlayer. The TGA result demonstrated an improvement in thermal stability of the Al-pillared clay compared with the untreated particles. SEM and EDX results showed the presence of aluminum aggregates on the surface of clay. It was also found that Al ions affect electromagnetic properties of the clay particles.     

A superhydrophobic magnetic elastomer actuator for droplet motion control

For the fast droplet transportation on an open surface, a new magnetic elastomer with a superhydrophobic surface has been developed. Because the surface is superhydrophobic, the water droplet can easily roll off on the surface. The movement of the droplet was controlled by a deliberate local deformation of the surface of the elastomer induced by magnetic actuation. The direction and speed of the droplet motion was easily controlled by changing the surface topography using magnetic force. We also demonstrate the applicability of the devices as a new type of open‐surface digital microfluidics using a simple chemical reaction. Copyright © 2013 John Wiley & Sons, Ltd.     

Novel toughened automotive clearcoats modified by a polyester‐amide hyperbranched polymer: structural and mechanical aspects

The present work attempts to study the mechanical properties and toughness behavior of a typical acrylic melamine clearcoat modified by a polyester‐amide hyperbranched polymer (HBP). Formulations were such that 0, 5, 10, 25 and 50% (molar percent) of total acrylic hydroxyl groups were stoichiometrically substituted by those of HBP. Bulk and surface of the clearcoats were studied by various mechanical techniques including hardness, tensile, dynamic mechanical thermal analysis (DMTA), nano‐indentation and scratch tests. In addition a scanning electron microscope (SEM) was utilized to observe the morphology of the fractured films. The bulk mechanical properties showed that a low loading (5 molar %) of HBP was sufficient to considerably increase the bulk hardness, cross‐linking density and toughness. DMTA and SEM results proved the occurrence of a single‐phase blend and that the shear deformation was the main toughening mechanism of HBP modified clearcoats. In general, it was revealed that the HBP not only could act as an excellent compatible toughening agent, but also maintained the clarity of the clearcoat and increased its scratch resistance. Copyright © 2013 John Wiley & Sons, Ltd.     

Strong covalent bonding modulated graphene oxide/epoxy interfacial enhancement and advanced corrosion resistance

Abstract

Chemically functionalized graphene oxide [multi-amino functionalized graphene oxide (MAGO)] was achieved by building covalent bonds between graphene oxide (GO) and a small molecule containing benzene structure and multi-amino groups. Fourier transform infrared, X-ray diffraction, X-ray photo electron spectroscopy and TEM-EDX results certified that the molecule was successfully grafted onto GO nanosheets. Subsequently, functionalized GO was incorporated into waterborne epoxy (EP) coating through ball-milling method. This molecular design can significantly improve the dispersion of MAGO in EP matrix, as well as the compatibility and interaction between MAGO and EP. Compared with GO/EP, the water absorption of MAGO/EP decreased from 4.38 to 2.59%, the adhesion strength of MAGO/EP increased from 4.72 to 6.32?MPa after immersion of 40?days in 3.5% NaCl solution. Incorporation of 1?wt% of MAGO into EP matrix prominently improved the long-term corrosion resistance. The impedance modulus of GO/EP coating decreased by four orders after 40 days immersion, while that of MAGO/EP coating only decreased by one order. The impedance modulus was still 1.47?×?10⁸ Ω cm², and two-time constant wasn’t detected for MAGO/EP coating. This research developed a novel green anticorrosion coating with enhanced durability for metal protection.