Currently, isocyanate modified asphalt (IMA) has gradually attracted attention in the pavement field due to its good mechanical properties and environmental benefits. However, there also exists some challenges, such as high viscosity and poor low-temperature performance, for its further application. In this study, an environmental-friendly potential solving method is proposed by employing waste engine oil (WEO) as a co-modifier with polyaryl polymethylene isocyanate (PAPI). And the effect and modification mechanism of WEO and PAPI on neat asphalt are studied. Specifically, the optimal compositions of PAPI/WEO modified asphalt (PWMA) were firstly determined by learning the effects of the PAPI and WEO amounts on the viscosity, high- and low- temperature performance of neat asphalt. Then, the traditional physical properties, storage stability and aging resistance of PWMA and SBS modified asphalt (SBSMA) were analyzed and compared. Finally, the performance improvement mechanism of PWMA was detected by microscopic analyses. The result shows that adopting WEO as a kind of co-modifier can prepare excellent performance modified asphalt with PAPI. The prepared PWMA qualifies similar viscosity and high- and low- temperature performance to SBSMA, while has the better storage stability and aging resistance. Microscopic test results reveal that in the PWMA, PAPI reacts chemically with the neat asphalt to generate carbamate or urea macromolecular products, while WEO mainly plays the role of adsorbent and filler. These findings are significant for guiding the performance regulation of IMA by the environmental-friendly method.

The conventional linear prediction has discontinuous estimated speed and position, and the error of flux linkage reduces the estimation accuracy. To solve the above problems, this article proposes a quadrature feature position observer for switched reluctance motor (SRM) at medium and high speeds, which includes harmonic decouple network (HDN), multiple second-order generalized integrator (MSOGI) and quadrature signal generator. This method uses HDN and MSOGI to filter the nonfundamental frequency of the feature position signal. Then a quadrature signal generator to transform the feature position signals into a set of quadrature signals, and the rotor position and speed are estimated by using the phase locked loop. Compared with the linear prediction method, proposed method has higher estimation accuracy, and there are no discontinuous estimated speed and position. In addition, this method does not need to measure the 3-D magnetic characteristics, requires less data storage space, the implementation is simpler, and has a wider application range. Eventually, the effectiveness of this method is verified on the 750 W 12/8 SRM setup, experimental results show that proposed method can improve the steady state and transient performance of sensorless control system.

Silica scaling has become a common problem in membrane systems due to the ubiquity of silica in the natural environment. In this work, a series of N-[3-(dimethylamino)propyl]methacrylamide-grafted hydroxyethyl cellulose (DHEC) with different grafting ratios was designed and used as a silica scaling inhibitor. The performances and mechanisms of DHEC in the inhibition of silica scaling were evaluated in detail by static and reverse osmosis (RO) tests. The maximum inhibition efficiency of DHEC with the grafting ratio of 97% reached as high as 77.20% +/- 0.26% in the static test. The permeate flux in the presence of this DHEC gradually decreased and was eventually maintained at 89.12% after 10 h of RO operation. The efficient mitigation of silica scaling was ascribed to the synergistic effect of the grafted copolymer, specifically, the hydrophilic cellulose backbone of DHEC exerted a dispersion effect and the cationic grafted chains acted as aggregators to inhibit silica scaling in the solution and at the membrane surface. This synergistic effect cannot delay the induction time of silica polymerization but can change the dominant mode of polymerization in the solution from the first-order to the second-order reaction as confirmed by the kinetic study. Thus, DHEC is an efficient and environmentally friendly inhibitor with high application potential for membrane fouling control in RO operations.

The instinct brittleness of epoxy resin is one of the challenges to the durability of epoxy asphalt pavements, which may cause various failures, such as cracking, potholes and delamination. To improve the toughness of epoxy asphalts, polymer tougheners have been commonly introduced. On the other hand, the rapid accumulation of unrecycled end-of-life polyethylene terephthalate (PET) waste brings a serious environmental problem. Addressing this, the research aims to explore the use of recycled PET (rPET) as a value-added toughener for epoxy asphalt binders. To obtain this goal, waste PET bottles were cut into flakes and integrated into asphalt binders to prepare rPET modified epoxy asphalt binders. The effect of the rPET content on the phase-separated morphology, rotational viscosity and mechanical and thermal properties of epoxy asphalt binder was studied. Notably, rPET dissolved in the asphalt binder, preventing the occurrence of phase separation in the discontinuous phase of rPET modified epoxy asphalt binders. The addition of rPET increased the viscosity, dynamic modulus and the glass transition temperature (Tg) of epoxy of epoxy asphalt binder. Furthermore, the mechanical properties and low-temperature performance of epoxy asphalt binder were also augmented. Remarkably, with the addition of 3 wt% rPET, the toughness of epoxy asphalt binder increased by 48%.

Waterborne polyurethane asphalt emulsion (WPUA) is an environmentally friendly bituminous material, whose performance is highly dependent on the phase structure of the continuous phase. In this paper, WPUAs in the vicinity of phase inversion were prepared using waterborne polyurethane (WPU) and asphalt emulsion. The chemical structures, thermal stability, dynamic mechanical properties, phase-separated morphology and mechanical performance of WPUAs were studied. Fourier-transform infrared (FTIR) spectra revealed that there are no –NCO bonds in either the pure WPU or WPUAs. Moreover, the preparation of WPUA is a physical process. The addition of WPU weakens the thermal stability of asphalt emulsion. WPU improves the storage modulus of asphalt emulsion at lower and higher temperatures. The glass transition temperatures of the WPUA films are higher than that of the pure WPU film. When the WPU concentration increases from 30 wt% to 40 wt%, phase inversion occurs; that is, the continuous phase shifts from asphalt to WPU. The WPUA films have lower tensile strength and toughness than the pure WPU film. However, the elongations at break of the WPUA films are higher than that of the pure WPU film. Both the tensile strength and toughness of the WPUA films increase with the WPU concentration. Due to the occurrence of phase inversion, the elongation at break, tensile strength and toughness of the WPUA film containing 30 wt% WPU are increased by 29%, 250% and 369%, respectively, compared to the film with 40 wt% WPU.

The performance and phase-separated microstructures of epoxy asphalt binders greatly depend on the concentration of epoxy resin or bitumen. In this paper, the effect of the epoxy resin (ER) concentration (10–90%) on the viscosity, thermo-mechanical properties, and phase-separated morphology of warm-mix epoxy asphalt binders (WEABs) was investigated using the Brookfield rotational viscometer, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and laser scanning confocal microscopy (LSCM). Due to the high reactivity of epoxy resin, the viscosity of WEABs increases with time. Furthermore, the initial viscosity of WEABs decreases with the ER concentration. Depending on the ER concentration, the viscosity–time behavior of WEABs is divided into three stages: slow (10–40%), fast (50–80%), and extremely slow (90%). In the slow stage, the viscosity slightly increases with the ER concentration, while the fast stage shows an opposite trend. DSC and DMA results reveal that WEABs with 10–80% ER exhibit two glass transition temperatures (Tgs) for cured epoxy resin and bitumen. Moreover, the Tgs of epoxy resin and bitumen increase with the ER concentration. However, WEAB with 90 % ER has only one Tg. LSCM observation shows that phase separation occurs in all WEABs. For WEABs containing 10–40% ER, spherical epoxy particles act as the discontinuous phase and disperse in the continuous bitumen phase. However, in WEABs with 50–90% ER, phase inversion takes place. Contrarily, bitumen particles disperse in the continuous epoxy phase. The damping properties of WEABs with the continuous epoxy phases increase with the ER concentration, while the crosslinking density shows an opposite trend. The occurrence of phase inversion results in a sharp increase in the tensile strength of WEABs. For WEABs with the continuous epoxy phases, the elongation at break increases with the ER concentration. The toughness first increases and then decreases with the ER concentration. A maximum toughness value shows at 70% ER.

Thermal contact resistance of thin film materials is an important issue in the heat management of highly integrated microelectronic systems. We proposed a strategy of Flash DSC measurement to characterize simultaneously thermal contact resistance and cross-plane thermal conductivity of Nylon 66 thin films with three thicknesses. We obtained the thermal contact resistance 1.317 x 10-5 m2 K/W at the interface between the sensor and the thin films, which showed as high as 30% in the total thermal resistance of 10 mu m thickness thin films. The cross-plane thermal conductivity 0.32 W/(m K) becomes slightly larger than our previous result 0.25 W/(m K), owing to the elimination of thermal contact resistance. Our steady-state measurement could be complemental to ASTM 5470 for the measurement of thermal contact resistance and thermal conductivity in the micrometer scale.

Cation-π interactions underlie many important processes in biology and materials science. However, experimental investigations of cation-π interactions in aqueous media remain challenging. Here, we studied the cation-π binding strength and mechanism by pulling two hydrophobic polymers with distinct cation binding properties, i.e., poly-pentafluorostyrene and polystyrene, in aqueous media using single-molecule force spectroscopy and nuclear magnetic resonance measurement. We found that the interaction strengths linearly depend on the cation concentrations, following the order of Li^{+}<NH_{4}^{+}<Na^{+}<K^{+}. The binding energies are 0.03-0.23  kJ mol^{-1} M^{-1}. This order is distinct from the strength of cation-π interactions in gas phase and may be caused by the different dehydration ability of the cations. Taken together, our method provides a unique perspective to investigate cation-π interactions under physiologically relevant conditions.

Four starch-based coagulants with similar charge densities but different chain architectures and hydrophilicities were designed and fabricated. These are a linear and hydrophilic coagulant, St-CTA (Starch-3-chloro-2hydroxypropyl triethyl ammonium chloride); a graft and hydrophilic coagulant, CS-AM-DMC (cationic starchgraft-poly[2-methacryloyloxyethyl trimethyl ammonium chloride and acrylamide]); and two graft and partially hydrophobic coagulants, CS-AM-DML (cationic starch-graft-poly[methacrylic acid 2-(benzyldimethylaminio) ethyl chloride and acrylamide]) and CS-AM-DMR (cationic starch-graft-poly[2-(methacryloyloxy)-N,N-dimethylN-alkyl ammonium chloride and acrylamide]) with aromatic and n-octane groups respectively. These starchbased coagulants in conjunction with polysilicic acid were employed in a current major environmental challenge which is to efficiently remove nano-sized plastics (NPs) from water. NPs of polystyrenes, polymethyl methacrylates and polyvinyl chlorides were removed from different water sources under various conditions of pH and salinity. The effects of the chain architectures and hydrophilicities of the starch-based coagulants on the NPs removal have been investigated in detail. According to experimental evidence, three graft starch-based coagulants exhibited higher NPs removal efficiencies and better flocs properties than the linear St-CTA. This was attributed to the superiority of the graft chain architecture in the graft starch-based coagulants causing higher charge neutralization efficiencies in coagulative removal of NPs. In the three graft starch-based coagulants, CSAM-DMR and CS-AM-DML with partially hydrophobic structures were more effectively to remove three NPs than CS-AM-DMC, and produced large, compact, durable and rapidly regrown flocs, due to the synergistic effects of charge neutralization and hydrophobic association. The interaction energies between NPs and the coagulants obtained from the extended Derjaguin-Landau-Verwey-Overbeek theory further confirmed that CS-AM-DMR and CS-AM-DML could achieve faster coagulation and thus higher efficiency in NPs removal. In addition, the NPs removal efficiency increased in acidic and highly saline solutions. These results obtained are of importance in guiding the design and selection of suitable polymeric coagulants for efficiently treating target contaminants in water.

Crystallization behaviors of alkane side-chains in densely grafted comb-like vinyl or acrylate polymers are influenced by their long-chain backbones as observed in experiments. By means of dynamic Monte Carlo simulations of the lattice polymer model, we compared cooling and isothermal crystallization behaviors of side chains in bulk alternatingly grafted polymers separately holding crystallizable and non-crystallizable long-chain backbones. The results of a series of side-chain lengths showed that both non-crystallizable backbones and very short side chains suppress side-chain crystallization in agreement with experiments, demonstrating the constraint effects of the backbone on side-chain crystallization. However, both crystallizable and non-crystallizable long-chain backbones maintain their nearly random-coil conformation over side-chain crystallization, not adopting the expected bottle-brush shapes. We discussed the related experimental observations on crystal morphologies that derived the bottle-brush assumption. Our observations facilitate a better understanding of structure-property relationships for side-chain crystallization in densely grafted comb-like polymers holding relatively long backbones.

Microplastic (MP) pollution has increasingly become an enormous global challenge due to the ubiquity and uncertain environmental performance, especially for nano- and micro- sized MPs. In this work, the performance and mechanisms in coagulation of 100 nm-5.0 μm sized polystyrene particles using an etherified starch-based coagulant (St-CTA) assisted by polysilicic acid (PSA) were systematically studied on the basis of the changes in MPs removal rates under various pH levels and in the presence of different coexisting inorganic and organic substances, zeta potentials of supernatants, and floc properties. St-CTA in conjunction with PSA had a high performance in coagulation of nano- and micro- sized MPs from water with a lower optimal dose and larger and compacter flocs. Besides, the MPs removal rate can be improved in acidic and coexisting salt conditions. The efficient performance in removal of MPs by this enhanced coagulation was owing to the synergic effect, that is, the effective aggregation of MPs through the charge neutralization of St-CTA followed by the efficient netting-bridging effect of PSA. The effectiveness of this enhanced coagulation was further confirmed by removal of two other typical nano-sized MPs, such as poly(methyl methacrylate) and poly(vinyl chloride), from different water sources including tap water, river water, and sludge supernatant from a sewage treatment plant. This work provided a novel enhanced coagulation technique that can effectively remove nano- and micro- sized MPs from water.

Epoxy asphalt mixtures have been extensively used in the construction of steel deck bridges. The fatigue cracking formed during long-term service has become the main failure of epoxy asphalt mixtures due to the inherent brittleness of epoxy resin. To improve the toughness of the mixture to resist fatigue cracking, graphene nanoplatelets (GNPs) were used to modify the warm-mix epoxy asphalt binder (WEAB). The thermal stability, viscosity-curing time behavior, phase separation, dynamic mechanical properties and mechanical performance of GNP modified WEABs were investigated by various techniques. The presence of GNPs enhanced the thermal stability of the neat WEAB. The addition of GNPs increased the viscosity of the neat WEAB at the later stage of cure reaction and thus shortened the allowable construction time of epoxy asphalt mixtures. However, the viscosities of all modified WEABs containing less than 1.0 wt% GNPs meet the general specifications of epoxy asphalt materials for paving roads and bridges. Confocal microscopy observation revealed that GNPs dispersed in the discontinuous asphalt phase of epoxy asphalt binder. Meanwhile, the existence of GNPs altered the phase-separated morphology of the neat WEAB. GNPs slightly lowered the glass transition temperatures of both epoxy and asphalt and the damping ability of the neat WEAB. GNPs significantly improved the mechanical properties of the neat WEAB, especially for their tensile strength and toughness, increased by 46% and 41%, respectively, with the addition of 0.2 wt% GNPs.

采用手持式X射线荧光光谱仪（pXRF）现场无损对照检测了南京大学博物馆收藏的国家一级文物敦煌莫高窟出土唐人写本《大方便佛报恩经残卷》朱书和血书字迹主要重金属元素成分。通过检测字迹中汞元素和铁元素相对含量多少，结合颜色深浅，鉴定血书中的浅色字迹含有较为丰富的铁元素，应为血液成分所带来。我们首先使用pXRF测试了古代常用红色颜料主要成分含汞元素的朱砂粉、含铁元素的三氧化二铁、两者50:50和99:1混合物浸迹以及动物干血迹中汞元素和铁元素的含量，对照X射线能谱仪（EDX）结果证明pXRF对朱砂中汞元素和铁元素都有很好的检测响应，即使血迹中微量的铁元素也能很清晰地检测出来。我们随后使用pXRF对馆藏的朱书和血书中的字迹对照颜色进行元素相对含量分析，结果显示朱书的字迹普遍颜色较深，主要成分为朱砂；血书中大部分颜色较浅的字迹主要成分为血和朱砂的混合物，而血书中少部分颜色较深的字迹则是由朱砂为主要成分的颜料修补所致。本文为现场无损鉴定成书时间较长的文物血经提供了一种较为可靠的原位无损检测化学方法，可以作为大学化学知识跨学科应用的一个课堂讲解例子。

Graphene oxide (GO) with 0.2, 0.5, and 1.0 wt% loading was used to modify warm-mix epoxy asphalt binders (WEABs). The thermal stability, structure of GO, rotational viscosity-curing time performance, dynamic moduli, glass transitions, damping ability, mechanical performance, and phase-separated morphology of GO/epoxy asphalt composites were investigated in the laboratory. GO significantly enhanced the thermal stability of the pure WEAB. X-ray scattering analysis revealed that GO layers were delaminated in the epoxy asphalt binder. GO accelerated the cure reaction of the pure WEAB and thus resulted in higher rotational viscosity of GO/epoxy asphalt composites. Furthermore, the viscosity of the modified WEABs slightly increased in the GO content. GO increased the dynamic moduli and T(g)s of both epoxy and asphalt for the pure WEAB. However, the damping ability of GO/epoxy asphalt composites was similar to that of the pure WEAB. Confocal microscopy observations revealed that GO was dispersed in both asphalt and epoxy phases of the phase-separated WEAB. The asphalt domains in the continuous epoxy phase became more spherical and uniform with the existence of GO. Moreover, the dispersion of epoxy in the discontinuous asphalt phase became more evident. The mechanical properties of the pure WEAB were greatly improved with the addition of GO. The tensile toughness and strength of the pure WEAB increased by 31% and 33%, respectively, with the addition of 0.2 wt% GO.

Asphaltenes tend to aggregate to nanoparticles or clusters in crude oil and solvents over a wide concentration and temperature range. In the present paper, asphaltenes extracted from the base asphalt was used as a filler to introduce into epoxy resin. The microstructure and evolution of asphaltenes aggregation in the epoxy resin were observed using laser scanning confocal microscopy. Furthermore, the effect of asphaltenes on the viscosity, dynamic mechanical behavior, thermostability, mechanical properties of epoxy resin was evaluated by Brookfield rotational viscometer, dynamic mechanical analysis, thermogravimetric analysis and universal testing machine. The presence of asphaltenes increased the viscosity of the neat epoxy during all stages of cure reaction. The viscosity of epoxy/asphaltenes composites increased with the filler concentration. Fractal asphaltenes aggregation formed in the composites with 1 mass% asphaltenes. Network microstructures of asphaltenes aggregation appeared in the epoxy phase with a further increase of asphaltenes content. Moreover, the increase of asphaltenes loading resulted in denser network microstructures in the epoxy matrix. Aggregation evolution revealed that asphaltenes particles redispersed evenly in the epoxy resin in the form of some aggregates at the beginning of curing. During the cure reaction of epoxy, asphaltenes aggregates started to agglomerate and grow to network microstructures. The presence of asphaltenes led to the enhancement of the storage modulus of the neat epoxy at the rubbery stage. The glass transition temperature (T-g) of the epoxy composites slightly increased with the increase of asphaltenes loading. The epoxy composite with 5 mass% asphaltenes had higher T-g than the neat epoxy. The inclusion of asphaltenes had a negligible effect on the damping properties and thermal stability of the neat epoxy. The aggregation and heterogeneous dispersion of asphaltenes resulted in the decrease of the tensile strength and elongation at break of the neat epoxy. However, the inclusion of asphaltenes significantly enhanced Young's modulus of the neat epoxy. Young's modulus of the neat epoxy was increased by more than fourfold with the addition of 5 mass% asphaltenes.

Core-shell rubber (CSR) is a good candidate for toughening epoxy asphalt binders. However, the knowledge of the effect of the core polymer on the performance of CSR modified hot-mix epoxy asphalt binder (HEAB) is not completed and systematic yet. In this paper, CSR modified HEABs were prepared by the incorporation of 2 wt% CSR particles with different core polymers, which were in turn subjected to viscous measurements, confocal microscopy, thermogravimetric analysis, dynamic mechanical analysis and tensile tests. The results revealed that the viscosity of CSR with styrene-butadiene copolymer (SB) core (CSRSB) modified HEAB is higher than that of CSR with polybutadiene (PB) core (CSRPB) modified HEAB during curing. The shell destruction of CSR particles resulted in the swelling of the core polymers and dispersion of swollen core polymer particles in the epoxy phase in the micron scale along with asphalt particles. The phase separation of CSRPB modified HEAB occurred in the spinodal decomposition mode, which was different from the nucleation and growth mechanism of the neat and CSRSB modified HEABs. The area fraction of swollen PB particles in the CSR modified HEAB was greater than that of swollen SB particles. The core polymer had a negligible effect on the thermal stability of CSR modified HEABs. The glass transition temperatures of epoxy and asphalt, damping ability and mechanical properties of the neat HEAB were increased with the addition of CSR particles. Especially, CSRPB modified HEAB had higher tensile strength and toughness than CSRSB modified HEAB. With 2 wt% CSRPB particles being adding, the tensile strength, elongation at break and toughness of the neat HEAB were increased by 53%, 42% and 110%, respectively.

Brittleness is an inherent shortcoming of epoxy resin which results in the longitudinal fatigue cracking of mixtures during the long service time of orthotropic steel deck bridges. In this paper, this problem was addressed by introducing a reactive thermoplastic elastomer, epoxidized styrene–butadiene–styrene copolymer (ESBS) into epoxy asphalt binder (EAB). Epoxy ESBS modified asphalts (EESBAs) with various epoxidation degrees were prepared. Double phase separation occurred in the EESBAs. In the EESBAs with 18% and 31% epoxidation degrees, most of ESBS domains dispersed on the edge of the secondary asphalt phase and in the epoxy phase. Furthermore, the size and number of ESBS domains decreased in the epoxidation degree. However, un-epoxidized SBS domains completely dispersed the asphalt phase and all ESBS domains moved to the epoxy phase when the epoxidation degree increased to 39%. In EESBAs, the average diameters of asphalt domains increased in the epoxidation degree. The inclusion of ESBS increased the viscosity of the pure EAB and the viscosity of EESBAs increased in the epoxidation degree. Nevertheless, all EESBAs had at least a 150-min allowable construction time. By adding 2 wt% ESBS with 39% epoxidation degree, the glass transition temperature (Tg) decreased. The Tg of EESBAs decreased in the epoxidation degree. The inclusion of ESBS greatly enhanced the damping properties of the pure EAB. The elongation at break and toughness of the pure EAB were remarkably increased by 263% and 93%, respectively, with the incorporation of 2 wt% ESBS with 39% epoxidation degree. Furthermore, the toughness of EESBAs increased in the epoxidation degree.

Zero-valent aluminum (ZVAl) is a promising reductant because of its relatively low redox potential, which can efficiently activate molecular oxygen to generate reactive oxygen species. However, its long-term performance is limited by the intrinsic dense oxide layer and the passivation effect of the accumulative Al-(hydr)oxide on its surface during the reaction. In this study, four clay minerals with different compositions were mixed with ZVAl by ball milling to obtain four composites of ZVAl and clay (ZVAl-Clay), which were used to degrade a high concentration of 4-chlorophenol (4-CP) under ambient conditions. The oxidation efficiencies of different ZVAl-Clays were strongly relevant to Fe contained in the clay minerals. The Fe-free ZVAl-Clay presented poor oxidation performance, whereas the reaction efficiencies of those ZVAl composites with Fe-bearing clays exhibited varying degrees of improvement. In comparison with the original ZVAl, the highest oxidation rate increased by 23 times, the maximum increased OH production was approximately 8 times, and the corresponding mineralization efficiency improved by 38.7%. However, the levels of improved oxidation performance of various ZVAl-Clays were not positively correlated with their actual total Fe contents, and their degradation efficiencies might also be affected by other physical and/or chemical properties of different clays. The synergistic mechanism revealed by various characterizations was that electron transfer might occur from ZVAl to the structural Fe(III) of the clay through the basal plane or edge of clays triggered by ball milling. Thus, the partially produced Fe(II) on the clay surface promoted the Fenton-like reaction to decompose H2O2 into OH for efficient oxidation of 4-CP. In short, the ZVAl composites with Fe-bearing clays deserved further exploration as potential materials for efficient degradation of organic matters in wastewater samples.

A series of actinia-shaped lignin-based adsorbents (LNAEs) featuring lignin(LN) as the core and grafted poly(acrylic acid) (PAA) as the tentacle were designed and fabricated. LNAEs were applied to remove ofloxacin and ciprofloxacin from water, and their maximum adsorption capacities were 0.835 and 0.965 mmol/g at pH 6.0, respectively. However, their adsorption capacities were up to about 20 % and 31 % reductions in the present of NaCl and humic acid, respectively. Electrostatic attraction (EA) and hydrogen bonding (HB), including ordinary HB and negative charged auxiliary HB, were mainly involved in adsorption. Experimental and calculation results indicated HB contributes more than EA. The effects of two structural factors of LNAEs, namely, PAA branched-chain length(L) and distribution density(D), on the adsorption performance associated with HB and EA, were quantitatively discussed using a binary nonlinear model based on phenomenological theory. The fitting results were completely consistent with the experimental findings. D was more efficient than L in promoting HB and EA in adsorption due to the cooperative effects of adjacent branched-chains and enhanced activity of terminal groups. This study provides a better understanding of the structure-activity relationship of surface grafting-modified adsorbents and fundamental guidance for the exploitation and design of novel and efficient adsorbents.

In this work, a simple and environmentally-friendly enhanced coagulation, by using a cationic starch-based coagulant (starch-3-chloro-2-hydroxypropyl trimethyl ammonium chloride, St-CTA) coupled with an optimized polysilicic acid (PSA), has been tried to coagulate the kaolin suspensions and humic acid (HA) aqueous solutions, which are used as the simulated sources of inorganic colloidal particles and organic pollutant, respectively, in micro-polluted turbid surface water. Dosing of St-CTA and PSA at the same time is more efficient and more convenient than other two separated feeding methods in this enhanced coagulation process. The synergic coagulation process and mechanism were studied and discussed in detail based on the apparent coagulation performance, floc properties, and zeta potentials of supernatants. St-CTA caused an efficient charge neutralization, i.e. compression of electric double layer of kaolin particles and electrostatic adsorption of HA, followed by an effective netting-bridging effect of PSA, resulting in an improved purification performance. St-CTA with a higher charge density showed better purification performance due to enhanced charge neutralization effect. In addition to simulated water, the validation of this enhanced coagulation process was further confirmed by comparison with a conventional coagulant, polyaluminium chloride, in treating a real surface water. This work thus provides a simple and environmentally-friendly strategy to efficiently purify micro-polluted turbid surface water and further improve the water safety.