Multiscale approach to the morphology,structure, and segmental dynamics of complex degradable aliphatic polyurethanes

A multiscale approach spanning from the segmental (subnanometer) up to micrometer level was applied for detailed study of the self‐assembly of aliphatic block polyurethane (PU) elastomers. To understand the principles of the self‐organization of hard and soft segments in the complex multi‐component systems, several two‐component model PU samples, that is, the products of 1,6‐diisocyanatohexane (HDI) with three diols differing in the length and constitution were also prepared, characterized, and investigated: (i) polycarbonate‐based macrodiol (MD), (ii) biodegradable oligomeric diol (DL‐L; product of butane‐1,4‐diol and D,L‐lactide), and (iii) butane‐1,4‐diol (BD). The study (particularly ¹³C‐¹H PILGRIM NMR spectra) reveals complex internal organization and interesting (application appealing) behavior of multi‐component PUs. Hard segments (HDI+BD products) feature self‐assembled and significantly folded chain conformations with interdomain spacing 15–22 nm (small‐angle X‐ray scattering analysis). The small domains are hierarchically assembled in various structural formations of µm size (spherulites) depending on PU composition, as detected by transmission electron microscopy and atomic force microscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41590.     

Controlled Reversible Anchoring of η6‐Arene/TsDPEN‐ Ruthenium(II) Complex onto Magnetic Nanoparticles: A New Strategy for Catalyst Separation and Recycling

A new catalyst separation and recycling protocol combining magnetic nanoparticles and host‐guest assembly was developed. The catalyst, (η⁶‐arene)[N‐(para‐toluenesulfonyl)‐1,2‐diphenylethylenediamine]ruthenium trifluoromethanesulfonate [Ru(OTf)(TsDPEN)(η⁶‐arene)] bearing a dialkylammonium salt tag, was easily separated from the reaction mixtures by magnet‐assisted decantation, on basis of the formation of a pseudorotaxane complex by using dibenzo[24]crown‐8‐modified Fe₃O₄ nanoparticles. The ruthenium catalyst has been successfully reused at least 5 times with the retention of enantioselectivity but at the expense of relatively low catalytic activities in the asymmetric hydrogenation of 2‐methylquinoline.     

Photoregulated complexation,redox behavior,and photoluminescence of a supramolecular polymer solution

Reported in this paper is a new finding based on a spectroscopic and electrochemical study of a supramolecular polymer in dilute solution. Dissolved in a mixture of dichloromethane and acetonitrile, zinc‐tetraphenylporphyrin (ZnTPP) can complex with a polymethacrylate bearing an azopyridine moiety (AzPy) through the axial coordination between the metal and pyridyl group. The self‐assembled polymer (PAzPy–ZnTPP) displays different photoluminescence and redox behaviors compared with those of noncomplexed ZnTPP. Moreover, the reversible trans–cis‐photoisomerization of azopyridine upon UV and visible light irradiation was found to alter the equilibrium of the axial coordination between azopyridine and ZnTPP in solution, resulting in photoregulable redox potentials and fluorescence emission of the metalloporphyrin. The results suggest that supramolecular polymer solutions could enhance the mechanism of photoinduced change in the degree of complexation, which gives rise to a phenomenon of photoregulation of the electrochemical and optical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 744–750, 2006     

Preparation of multi‐level honeycomb‐structured porous films by control of spraying atomized water droplets

Honeycomb‐structured porous films have been widely applied in various industrial areas such as chemical sensors, tissue engineering, and micro reactors. In this article, one novel self‐assembly approach is proposed to fabricate well‐ordered polyphenylene oxide honeycomb films by a facile control of spraying ultrasonic humidifier atomized water droplets. Proper spraying retention time is necessary for porous films formation with highly uniform pore size. The effect of atomized water droplets flux on the pore size and the regularity of the hexagonal arrays were experimentally investigated. The pore size became larger with increasing the solution concentration. Especially, honeycomb films with two‐level pores were fabricated by spraying atomized water droplets two times and the influence of interval time on the two‐level honeycomb films formation was investigated. Apart from analysis of structural characteristics, self‐assembly mechanism was also discussed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41163.     

Pervaporation separation of sodium alginate/chitosan polyelectrolyte complex composite membranes for the separation of water/alcohol mixtures: Characterization of the permeation behavior with molecular modeling techniques

Polyelectrolyte complex (PEC) membranes were prepared by the complexation of protonated chitosan with sodium alginate doped on a porous, polysulfone‐supporting membrane. The pervaporation characteristics of the membranes were investigated with various alcohol/water mixtures. The physicochemical properties of the permeant molecules and polyion complex membranes were determined with molecular modeling methods, and the data from these methods were used to explain the permeation of water and alcohol molecules through the PEC membranes. The experimental results showed that the prepared PEC membranes had an excellent pervaporation performance in most aqueous alcohol solutions and that the selectivity and permeability of the membranes depended on the molecular size, polarity, and hydrophilicity of the permeant alcohols. However, the aqueous methanol solutions showed a permeation behavior different from that of the other alcohol solutions. Methanol permeated the prepared PEC membranes more easily than water even though water molecules have stronger polarity and are smaller than methanol molecules. The experimental results are discussed from the point of view of the physical properties of the permeant molecules and the membranes in the permeation state. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2634–2641, 2007     

Synthesis of a hypercrosslinked,ionic, mesoporous polymer monolith and its application in deep oxidative desulfurization

In this study, we used a facile and scalable strategy to produce a hypercrosslinked, ionic, mesoporous polymer monolith (HCIMPM). On the basis of structure‐directing polymeric crosslinking, the interconnected nanonetwork was formed through the in situ crosslinking of the homopolymer poly(vinyl imidazole) via a quaternization reaction, and its textural properties could be effectively adjusted by the block copolymer poly(ethylene oxide)‐block‐poly(propylene oxide)‐block‐poly(ethylene oxide)(PEO₂₀PPO₇₀PEO₂₀). The maximum specific surface area and pore volume were 212 m²/g and 1.08 cm³/g, respectively. Furthermore, the synthetic framework could be functionalized via the loading of PW₁₂ through ion exchange. The obtained HCIMPM with PW₁₂O₄₀^3? (PW‐HCIMPM) was applied in the oxidative desulfurization, and approximately 100% sulfur removal could be achieved in the model oil with hydrogen peroxide (30 wt %) as an oxidant. Moreover, the solid catalyst could be recovered readily and recycled at least six times without a significant decrease in the desulfurization efficiency. As for real diesel, we also observed that almost all of the original sulfur compounds could be converted in 120 min. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46280.     

Hierarchically porous graphitic carbon monoliths containing nickel nanoparticles as magnetically separable adsorbents for dyes

The hierarchically porous graphitic carbon monoliths containing nickel nanoparticles (HPGCM‐Ni) were fabricated via multi‐component co‐assembly in polyurethane (PU) foam scaffold associated with a direct carbonization process from triblock copolymer F127, diblock copolymer PDMS‐PEO, phenolic resol, and nickel nitrate and subsequent silicates removal with NaOH solution. The decomposable PU foam scaffold played important role in the process of multi‐component co‐assembly and macrostructure formation. The nickel salts were reduced to metallic Ni nanoparticles during the carbonization process. The obtained HPGCM‐Ni materials exhibited macropores of 100–450 μm, mesopore size of 7.2 nm, BET surface area of 725 m² g^?1, pore volume of 0.74 cm³ g^?1, and saturation magnetization of 2.3 emu g^?1. Using methyl orange as model dye pollutant in water, HPGCM‐Ni samples showed good adsorption capacity of 440 mg g^?1, exhibiting excellent adsorption characteristics desirable for the application in adsorption of dyes and separation under an external magnetic field. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41322.     

Adhesive and repulsive properties of water droplet impact on honeycomb surfaces through breath figure method

The honeycomb porous films of tadpole‐shaped polyhedral oligomeric silsesquioxane fluorinated acrylates copolymers were fabricated through breath figure method. The static hydrophobic properties were studied through water contact angles (CAs) and the rim width/pore size (W/D) values. It was found that the low W/D value and high fluorine content generally indicated a high water CA. The properties such as morphology variations, energy conversion, contact diameter, adhesive, and repulsive forces were investigated on the porous and pincushion films. Furthermore, the kinetic energy of the droplet was converted into surface energy and internal energy dissipation after it impacted the surface. The residual energy made the droplet to recoil and influenced the bouncing height. The contact diameter and bouncing height characterized the energy level of the surface, and determined the surface energies of the copolymer/water/air system as well as the wettability. Finally, the adhesion and repulsion of water droplet on different surface at the times of establish contact, maximum contact diameter, and maximum bouncing height were compared. This work was helpful for us to further understand and control the adhesive force and the repulsive force on the porous and pincushion structure films. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45476.     

A highly efficient dispersant from black liquor for carbendazim suspension concentrate: Preparation,self‐assembly behavior and investigation of dispersion mechanism

Compared with traditional approaches using synthetic amphiphilic block copolymers, alkyl chain cross‐linked lignosulfonate (ASL) with high molecular weight (Mw) from black liquor was synthesized and characterized by GPC, functional group content, FTIR, and ¹H‐NMR measurement, and then used as water soluble amphiphilic biopolymer to prepare polymersomes via solution self‐assembly. DLS illustrated the solution assembly behavior. The hollow nature of nanospheres was revealed by TEM. Moreover, the element analysis and XPS results revealed the hollow sphere structure with a hydrophilic core and a hydrophobic shell. It facilitated the efficient encapsulation of pesticide carbendazim into the hollow sphere via electrostatic interaction, which was investigated by SEM, TEM, elemental analysis and XPS. In our study, ASLs with different Mw from 20 kDa to 200 kDa all could exhibit the similar self‐assembly behavior, which suggests that the hollow spheres and the encapsulation experiment were easily duplicated from ASL polymers without structure dependence. Furthermore, the dispersion properties of ASL in the carbendazim suspension concentrate (SC) system were also investigated, which showed that SC with ASL exhibited better dispersion property and rheological performance than that of NSF and commercial LS. Preparation and application of polymersomes via self‐assembly from modified‐lignin from black liquor provide a promising and effective scaffold which can be conveniently obtained from cheap and renewable bioresource. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43067.     

Preparation and characterization of supported ordered nanoporous carbon membranes for gas separation

Supported ordered nanoporous carbon membranes (ONCM) were prepared by coating a membrane‐forming solution of resorcinol‐formaldehyde (RF) resin on plate support through solvent evaporation and pyrolysis. The membrane solution was formed by the organic‐organic assembly of RF resin with Pluronic F127 in the presence of triethyl orthoacetate and catalyst hydrochloric acid. The thermal stability of precursor, the microstructure, functional groups, and morphology and porous structure of resultant support and ONCM were investigated by the techniques of thermogravimetry, X‐ray diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy/transmission electron microscopy and nitrogen adsorption‐desorption, respectively. Results have shown that the as‐obtained ONCM has well‐developed porous regularity with bi‐modal narrow pore size distribution. ONCM is tightly adhered to the adopted phenolic resin‐based carbon support. Gases permeating through the ONCM are dominated by molecular sieving mechanism. The ideal gas separation factor of the supported ONCM can be reached to 46.4, 4.7 and 3.3 for H₂/N₂, CO₂/N₂ and O₂/N₂, respectively. The supported ONCM obtained in this work exhibits most promising application for permanent gas separation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39925.     

‘Bricks and mortar’ nanoparticle self‐assembly using polymers

Developments in self‐assembly methods allow access to hierarchical materials featuring a wide range of functionality and applications. Polymer‐based self‐assembly of nanoparticles opens up new avenues for the fabrication of highly structured nanocomposites that can serve as bridges between ‘bottom‐up’ and ‘top‐down’ methods. Of various interactions leading to self‐assembly of nanocomposites, hydrogen bonding and electrostatic interactions are commonly utilized. In this review, we illustrate the design and subsequent property tuning of various self‐assembled nanocomposite materials that were developed based on these interactions. Copyright © 2007 Society of Chemical Industry     

Analysis and modeling of drying behavior of knitted textile materials

Drying properties of textiles in summer and/or after any kind of physical activity resulted in sweating is of great importance for garments with high clothing comfort. This study analyzes the drying behavior of knitted fabrics produced from various fibers at different ambient air conditions. Drying kinetics and modeling of fabrics dried in standard environmental conditions were investigated in the first part. Polyester and lyocell fabrics were found to be the fastest drying samples. A two-stage modeling that is a combination of linear approach and thin-layer equations was used, and the best fitted equation was found to be the logarithmic one. The two-stage model was also proved to predict the drying rate. The second part included the effects of ambient humidity on drying times and rates. Drying time of polyester and polyester blended fabrics was affected by the increase in the humidity to a great extent. Furthermore, a quadratic function was found to be highly correlated with the computed data, so it was proposed to define the drying behavior by ambient air humidity and drying time.     

A perspective on polyoxometalates as versatile synthons for precisely hybridized polymer materials

We summarize the emerging advances of polyoxometalate (POM)–polymer hybrid materials in the last decade and chart the future possibilities in this field. The discussion is mainly focused on two critical roles of POMs: the structural synthon for fabricating well‐defined macromolecular architectures, and the functional synthon for advanced hybrid polymer materials in energy‐ and health‐related applications. The precise structures, modular synthesis and task‐directed functional design to overcome the current societal challenges are proposed to be a developing trend in POM–polymer hybrid materials. © 2019 Society of Chemical Industry     

Polymeric micelles based on hyaluronic acid and phospholipids: Design,characterization, and cytotoxicity

Novel amphiphilic copolymers were synthesized and characterized by ¹H NMR using Hyaluronic acid (HA) as a hydrophilic part and phosphatidylethanolamine (PE) including 1,2‐dimiristoyl‐sn‐glycerol‐3‐phosphatidylethanolamine (DMPE) and 1,2‐distearoyl‐sn‐glycerol‐3‐phosphatidylethanolamine (DSPE) as a hydrophobic segment. The newly developed HA‐PE copolymers form a micelle in an aqueous media. The micellar properties, including critical micelle concentration (CMC) with pyrene as a fluorescence probe and micelle morphology, using transmission electron microscopy were assessed. It was found that the CMC values for HA‐DMPE and HA‐DSPE were 15.5 and 13.4 μg/mL, respectively. Also micelles were spherical in shape and within the size range of 162–214 nm. The solubility of cholesterol, a highly hydrophobic compound, was enhanced to 0.25 mg/mL which is much higher than it is in water (0.0001 mg/mL). In vitro cytotoxicity assay of HA‐PE copolymers showed no toxicity on human breast cancer cell line (MCF‐7). These results suggest that HA‐PE micelles could be considered as a promising carrier for delivery of hydrophobic compounds. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40944.     

Multiscale molecular modeling in nanostructured material design and process system engineering

Atomistic-based simulations such as molecular mechanics, molecular dynamics, and Monte Carlo-based methods have come into wide use for material design. Using these atomistic simulation tools, we can analyze molecular structure on the scale of 0.1–10 nm. However, difficulty arises concerning limitations of the time and length scale involved in the simulation. Although a possible molecular structure can be simulated by the atom-based simulations, it is less realistic to predict the mesoscopic structure defined on the scale of 100–1000 nm, for example the morphology of polymer blends and composites, which often dominates actual material properties. For the morphology on these scales, mesoscopic simulations such as the dynamic mean field density functional theory and dissipative particle dynamics are available as alternatives to atomistic simulations. It is therefore inevitable to adopt a mesoscopic simulation technique and bridge the gap between atomistic and mesoscopic simulations for an effective material design. Furthermore, it is possible to transfer the simulated mesoscopic structure to finite elements modeling tools for calculating macroscopic properties for the systems of interest.In this contribution, a hierarchical procedure for bridging the gap between atomistic and macroscopic modeling passing through mesoscopic simulations will be presented and discussed. The concept of multiscale (or many scale) modeling will be outlined, and examples of applications of single scale and multiscale procedures for nanostructured systems of industrial interest will be presented. In particular the following industrial applications will be considered: (i) polymer-organoclay nanocomposites of a montmorillonite–polymer–surface modifier system; (ii) mesoscale simulation for diblock copolymers with dispersion of nanoparticels; (iii) polymer–carbon nanotubes system and (iv) applications of multiscale modeling for process systems engineering.     

Poly(amidoamine) dendritic structures,bearing different end groups,as adhesion promoters for urea–formaldehyde wood adhesive system

A series of core‐shell poly(amidoamine) (PAMAM) dendritic compounds bearing different end groups such as  OH, NH₂, and NH₃⁺⁻Cl up to the third generation were prepared via successive Michael addition of a nucleophilic core (ethylenediamine) to methylacrylate followed by amination steps using ethylenediamine for the amine‐terminated while ethanolamine for the hydroxyl‐terminated compounds, also the protonated ammonium salt terminated form was obtained by cationization of the amine‐terminated form using hydrochloric acid solution. The Surface activity and aggregation behavior of the corresponding aqueous solutions of the prepared generations with their different end groups were studied and confirmed by surface tension measurements using ring method technique. The prepared dendrimers showed high surface activity and the measurements revealed their ability to self aggregate in water at very low concentrations, critical aggregation concentrations (CACs). The CACs were found to decrease with increasing the generation number, which implies that molecular weight and structure play important rules in controlling the surface activity and CAC. The dendritic compounds proved to be effective as adhesion promoters for urea formaldehyde (UF) resins when applied as wood adhesive systems, which was ascribed in partial to the improved wetting over the substrate, a role that is fundamentally related to the huge number of function groups present at the interface. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Intrinsic viscosity,rheological property,and oil displacement of hydrophobically associating fluorinated polyacrylamide

The surface‐active polymer (FPAM) was synthesized by free‐radical polymerization of acrylamide (AM), 2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid (AMPS) and N ‐dodecyl‐N ‐perfluoro octane sulfonyl acrylamide (AMPD), which was prior prepared by reacting dodecylamine, perfluoro‐1‐octanesulfonyl fluoride, and acryloyl chloride. Parameters affecting the intrinsic viscosity ([η]) and apparent viscosity (η) of FPAM, such as reaction temperature, AMPD concentration, AMPS concentration, monomer concentration, initiator concentration, and pH were examined. Apparent viscosity and interfacial tension (IFT) of FPAM solution were evaluated. Subsequently, temperature tolerance and shear tolerance were investigated by comparing with hydrolyzed polyacrylamide (HPAM), and results indicated that the FPAM displayed better performances than HPAM. FPAM can reduce the IFT between crude oil/water, and the IFT values are around at 2.91 and 3.9 mN m^?1 corresponding to FPAM and HPAM/FC‐118. The sandpack model oil displacement experiment showed that water flooding can further increase the oil recovery to 15.01% (FPAM), compared with 9.26% oil recovery for HPAM, and 10.99% oil recovery for HPAM/FC‐118. The glass micromodel techniques for studying enhanced oil recovery get a good result and provide a useful reference for understanding the displacement behaviors in polymer flood process. It could be concluded that the introduction of fluorinated groups in the polymer chain was helpful in enhancing the oil displacement efficiency. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44672.