A novel type of hydrophobic association hydrogels (HA-gels) was prepared through micellar copolymerization of acrylic acid (AA), acrylamide (AAm) as basic monomers and a small amount of octylphenol polyoxyethylene ether acrylate with seven ethoxyl units (OP7-AC) as hydrophobic association monomer. The HA-gels exhibited desirable mechanical property and stably reversible phase transition between opaque and transparency. The influences of adding urea and varying AA:AAm molar ratio on the phase transition behavior were discussed, which indicated that the phase transition was introduced by forming or dissociating of hydrogen bonding between amide and carboxyl groups. The introduction of hydrophobic units (OP7-AC) to poly(acrylic acid-co-acrylamide) (P(AA-AAm)) copolymer would result in the adulterating and cross-linking effects on the transition temperature. The former sharply reduced the transition temperature while the later gradually raised it. The transition temperature became linearly dropping with the increasing sodium dodecyl sulfate (SDS) content in the HA-gels. Therefore, the phase transition temperature can be finely adjusted by means of changing AA:AAm ratio, concentration, OP7-AC and/or SDS dosages in the synthesis of HA-gels.

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Pickering polymerization of styrene stabilized by starch-based nanospheres to synthesize composite particles with different morphologies is reported.

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Polymerization at the liquid–liquid interface has attracted much attention for synthesizing ultrathin polymer films for molecular sieving. However, it remains a major challenge to conduct this process outside the alkane–water interface since it not only suffers water‐caused side reactions but also is limited to water‐soluble monomers. Here, we report the interfacial polymerization at the alkane/ionic liquid interface (IP@AILI) where the ionic liquid acts as the universal solvent for diversified amines to synthesize task‐specific polyamide nanofilms. We propose that IP@AILI occurs when acyl chloride diffuses from the alkane into the ionic liquid instead of being triggered by the diffusion of amines as in the conventional alkane–water system, which is demonstrated by thermodynamic partitioning and kinetic monitoring. The prepared polyamide nanofilms with precisely adjustable pore sizes display unprecedented permeability and selectivity in various separation processes.

BackgroundEthylenediaminetetraacetic acid (EDTA) pretreatment has been shown to overcome complement interference in the single-antigen bead (SAB) assay. However, a quantitative evaluation of its impact on the assay for preemptive application to diverse clinical samples is still lacking.MethodsSerum samples from 95 renal transplant candidates were tested with and without EDTA-pretreatment in parallel. Changes in mean fluorescence intensity (MFI) values were analyzed to determine the impact of EDTA-pretreatment and the characteristics of complement interference.ResultsMFI values from EDTA-treated and untreated sera showed good correlations (r = 0.99) and were linear after excluding outliers (slopes, 1; intercepts, −63.7 and −24.2 for class I and II, respectively). Using an assay cutoff of 2000 MFI, positive/negative assignments were concordant for 99% of the 9215 class I beads and 9025 class II beads tested. As defined by an MFI increment above 4000 after EDTA pretreatment, complement interference affected 172 class I beads in 12 samples (12.6%) and 60 class II beads in 7 samples (7.4%), and the findings were supported in 83% and 86% of these samples by dilution studies. In a case study, EDTA pretreatment prevented falsely low MFI values and facilitated the interpretation of titration curves. Finally, EDTA pretreatment reduced the coefficient of variance (CV) by 2.1% and 2.4% for class I and II beads respectively (P < 0.0001).ConclusionsIt is safe to preemptively treat all clinical samples with EDTA before SAB assay to prevent false negative results or falsely low MFI values. EDTA pretreatment has the added benefit of improved assay precision.

A scale-up model for photoreactors based on a comparative study of the photocatalytic efficiency of suspended and immobilized systems was developed. The model is independent of reactor size and configurations, and it assumes that photocatalytic efficiency is the same when normalized per unit of illuminated catalyst area in both systems. In all cases, phenol/TiO2 (Degussa P25) was selected as the photodegradation system. First, a kinetic model was built in an immobilized system based on the corresponding experimental data, and then predicted rates of phenol degradation in the suspended system were calculated using the above kinetic model combined with a simplified radiation model, which was expressed as an apparent form of the Lambert law. Second, to obtain experimental rates, experiments conducted in the suspended system were carried out under the same conditions used in the immobilized system. Ratios between experimental rates and predicted rates were obtained, revealing the differences in efficiency between the suspended and immobilized systems. The typical value of the ratio was 2.5−9.2, suggesting that the efficiency of the suspended system was 2.5−9.2 times higher than that of the immobilized system. The ratio decreased with increasing concentrations of both phenol and catalyst. When the catalyst concentration and initial concentration of phenol were set, the ratio became constant within the range of the light intensity of 1.71−3.60 mW cm−2. Finally, for photoreactor scale-up, the proposed model was validated in a larger photoreactor operated in the suspended system, and good agreements were obtained with errors less than 5%. This methodology provides an alternative to the scale-up of photoreactors, which allows for easier engineering applications.

Hydrophobically modified polyacrylamide (HMPAM) is synthesized by a free radical micellar polymerization method with low amounts of anionic long-chain alkyl, sodium 9-(and 10)-acrylamidostearate (NaAAS), which is derived from a renewable resource material, oleic acid. In this progress, the molar ratio of Sodium dodecyl sulfate (SDS) to NaAAS is adjusted, so polymers with different lengths of the hydrophobic blocks (NH 5 3 and NH 5 6) are obtained. The copolymers are characterized by 1 H NMR, and the polymer weight and polydispersity are determined by gel permeation chromatography. The solution behaviors of the copolymers are studied as functions of concentrations, pH, and added electrolytes by steady-flow and oscillatory experiments. The viscosities of these HMPAMs increase enormously above the critical concentration (c*). The sample with longer hydrophobic blocks exhibits better thickening effect. The rheological behaviors of aqueous solutions of HMPAMs are also investigated at different pH and brine environments. Low pH or the presence of brine promotes the intramolecular associating of hydrophobes for the both copolymers in semidilute solutions. The introduction of ionizable carboxylic group on the long hydrophobic side chain significantly influences the aggregation behaviors of the copolymers, leading to unique solution behaviors of the poly(AAm/NaAAS)