In order to develop a new epoxy resin (EP) possessing good thermal and mechanical properties as well as flame retardancy performance, the compound POSS-bisDOPO consisting of one polyhedral oligomeric silsesquioxane (POSS) and two unit of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) was synthesized and used as co-additive with tetrabutyl titanate to construct a phosphorous–silicon–titanium synergy system. Compared to pure EP, the char yields of the EP composites were increased. The LOI value and UL-94 ratings of the EP composite with a loading of 5% POSS-bisDOPO reached 31.0% and V-0 grade, respectively. The PHRR and THR reduced to 28.4 W g−1 and 1.7 kJ g−1. SEM results indicated that the char of the EP composites had an alveolate inner layer and continual compact outer layer, which was conducive to form effectively physical barrier to hinder the penetrating of oxygen and heat. DMA and three-point bending test results showed the mechanical property of the EP composites had no decline.

In this work, novel thin-film nanocomposite (TFN) nanofiltration (NF) membranes were developed through modification with maleic anhydride functionalized graphene oxide (MAH-GO) via interfacial polymerization (IP). First, MAH-GO was synthesized by linking MAH molecules to the electrophilic groups (C–OH) of GO nanosheets. The resulting materials were characterized in depth by FT-IR, TEM, SEM, AFM, XPS and Raman spectroscopy. Subsequently, the MAH-GO and GO nanosheets were individually introduced into the polypiperazine-amide (PPA) active layer of TFN NF membranes via IP between piperazine (PIP) and trimesoyl chloride (TMC). The influence of the MAH-GO or GO concentrations on the morphology and performance of TFN NF membranes was systematically investigated. Compared with TFC-blank, the TFN-MG-60 and TFN-GO-80 membranes demonstrated significantly enhanced separation performance without reduction of the salt rejection. Particularly, the water flux of TFN-MG-60 and TFN-GO-80 was found to be 49.3 L m−2 h−1 and 42.0 L m−2 h−1, respectively, corresponding to 176.7% and 150.5% of TFC-blank. Moreover, TFN-MG-60 demonstrated superior water permeability, antifouling capability and chlorine resistance to TFN-GO-80, which was attributed to the incorporation of MAH-GO nanosheets having more hydrophilic carboxyl groups. Meanwhile, TFN-MG-60 retained a high salt rejection rate of 97.6% to Na2SO4, comparable to that of TFC-blank. The MAH-GO nanosheets show great potential in developing high-performance TFN NF membranes to overcome the trade-off effect of conventional thin-film composite membranes.

The binding of chloroamphenicol (CPC) to bovine serum albumin (BSA) at 296 K, 303 K, and 310 K by fluorescence and UV–visible absorption spectroscopy were investigated under imitated physiological conditions. The experimental results showed that the fluorescence quenching mechanism between CPC and BSA was combined quenching (dynamic and static quenching) procedure at low CPC concentration, or a dynamic quenching procedure at high concentrations. The binding constants, binding sites and the corresponding thermodynamic parameters of the interaction system were calculated. According to Förster non-radiation energy transfer theory, the binding distance between CPC and BSA was calculated to be 3.02 nm. Both synchronous fluorescence and FT-IR spectra confirmed the interaction, and indicated the conformational changes of BSA. The effects of some common metal ions Ca2+, Ni2+, Mg2+, Fe2+, and Cu2+ on the binding constant between CPC and BSA were examined. Furthermore, we investigated the possible sub-domains on BSA that bind CPC by displacement experiments.Graphical abstractThe interaction between chloroamphenicol (CPC) and bovine serum albumin (BSA) was studied by fluorescence and UV–visible spectroscopy. The quenching mechanism, binding constants and binding distance were obtained. The effects of some common metal ions on the binding constant between CPC and BSA were examined. What’s more, we investigated the possible sub-domains on BSA that bind CPC by displacement experiments.Highlights► We explored the interaction of BSA and CPC by spectroscopic methods. ► The fluorescence quenching mechanism is combined quenching. ► The binding constants and binding sites were calculated. ► The synchronous fluorescence spectra indicated that the conformation of BSA has been changed. ► The displacement experiment indicated that CPC does bind at the region of site I.

A thin nanofiltration composite polyamidoamine/polyacrylonitrile (PAMAM/PAN) membrane was fabricated over a modified polyacrylonitrile (PAN) ultrafiltration membrane by in situ interfacial polymerization of poly(amidoamine) (PAMAM) dendrimer and trimesoyl chloride (TMC). The chemical structures and morphologies of the thus prepared composite PAMAM/PAN membrane were characterized by FTIR-ATR spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscope. The results showed that an ultrathin and dense layer linked by amine groups was formed on the surface of the supporting PAN membrane. The test for salt rejection of the composite PAMAM/PAN membrane exhibited the order: Na2SO4 ≈ MgSO4 > MgCl2 ≈ NaCl. In addition, under the operational pressure of 0.6–0.8 MPa, the rejection percentage of the membrane for Na2SO4 and PEG600 was higher than 90%, while for NaCl it was lower than 50%. The effects of interfacial polymerization processing conditions, such as reaction time, concentration of reactants, heat treatment temperature, salt concentration, operating pressure, and pH value of feed solution, on the performance of the composite PAMAM/PAN membrane were also investigated.Highlights► A novel thin nanofiltration membrane is consisting of the composite of PAMAM/PAN. ► PAMAM/PAN was fabricated by interfacial polymerization using PAMAM and TMC. ► An ultrathin and dense layer linked by amine groups was formed on the surface of PAN. ► The rejection percentage of the membrane for Na2SO4 and PEG600 were higher than 90%.

The interaction between pyrrolizine derivatives (PD) and bovine serum albumin (BSA) under imitated physiological conditions was analyzed by fluorescence and ultraviolet spectra. The experiments were conducted at three different temperatures (302, 306 and 310 K) and the results showed that PD caused the fluorescence quenching of BSA through a combined quenching procedure. The binding constant (Ka), binding-site number (n) between PD and BSA at different temperatures were obtained. According to Förster non-radiation energy transfer theory, the binding distance (r) between BSA and PD was calculated. The corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) were also obtained. The comparison of binding potency of PD and BSA suggested that the substituent on the benzene ring could enhance the binding affinity of PD and BSA. Finally, we investigated the possible sub-domain on BSA where bind PD by displacement experiments.Graphical abstractThe interaction between pyrrolizine derivatives (PD) and bovine serum albumin (BSA) was studied by fluorescence and UV–Vis spectroscopy. The quenching mechanism, binding constants, and binding distance were obtained. The comparison of binding potency of PD and BSA suggested that the substituents on the benzene ring influence the binding affinity of PD and BSA. We investigated the possible subdomain on BSA where bind PD by displacement experiments.Highlights► We explored the interaction between PD and BSA by fluorescence spectroscopy. ► The fluorescence quenching mechanism was combined quenching. ► The binding constants and binding sites were calculated. ► The substituent on the benzene ring enhanced the binding affinity of PD and BSA. ► The possible sub-domain on BSA where bind PD was investigated.