Abstract:The semiconductor photocatalytic technology with low energy consumption and no pollution is a new green chemical process. It is of great significance to research and develop the photocatalytic materials with high efficiency and corresponding visible light. As a typical MOFs material, NH₂-MIL-125(Ti) has an important application prospect in the field of photocatalysis, but it has the disadvantages of fast recombination of photo-generated electrons and holes, etc. The effects of titanium ester type, reactant concentration, solvent ratio and crystallization time on the morphology of NH₂-MIL-125(Ti) are introduced. Next, the methods to improve the photocatalytic activity of NH₂-MIL-125(Ti) were summarized. Subsequently, the research fields of NH₂-MIL-125(Ti) photocatalyst at home and abroad were reviewed. Finally, the development direction of NH₂-MIL-125(Ti)-based visible light catalysts was proposed.

Abstract:Epoxy resin coating is widely used in the field of metal anti-corrosion because of its excellent corrosion resistance and good adhesion to metal surface. However, defects and holes will be formed during the curing process of the coating film, and the corrosive medium can directly contact the metal surface. In order to develop excellent and durable anti-corrosion coatings, the researchers prepared a variety of epoxy resin anti-corrosion coatings using different methods and materials. This review introduces the preparation and properties of nanoparticle-modified epoxy anti-corrosion coatings, superhydrophobic epoxy anti-corrosion coatings, self-healing epoxy anti-corrosion coatings, conductive polymer-modified epoxy anti-corrosion coatings and bio-based material modified epoxy anti-corrosion coatings. However, these kinds of anti-corrosion coatings have their own limitations, and new epoxy anti-corrosion coatings should be explored in the future, which can improve the anti-corrosion performance of the coating while taking into account other properties, so that epoxy-based anti-corrosion coatings will develop in the direction of functional intelligence.

Abstract:Compared with lithium-ion batteries, magnesium-ion batteries have been widely concerned due to their good merits of high energy density, low price, highly safe usage and operation, and environmentally-friendly type. Rechargeable magnesium batteries are believed to be very promising in the application of large load energy storage. However, the compatibility between electrolyte and electrode material of magnesium-ion battery has not reached a relatively ideal state. Therefore, the development of high stable cathode materials, wide voltage window and non-passivating electrolytes are the keys to promoting the industrial application of magnesium-ion batteries. In this paper, the research status at home and abroad about rechargeable magnesium-ion batteries are reviewed systematically through the review-analysis of the published peer articles. The research progress on the battery system’s main components including cathode materials and electrolytes are elaborated in detail. This review paper also discusses the existing problems of rechargeable magnesium-ion batteries, and provides summary and prospective for their development direction.

Abstract:In recent years, indoor air pollution has gradually aroused people's wide concern, and volatile organic compounds (VOCs) are the main source of this problem. Photocatalytic coating, as a novel VOCs purification technique, could degrade VOCs into water and CO2 under sunlight spontaneously, which is efficient and energy-saving, and will not produce secondary pollution. So it has attracted extensive attention and in-depth research by researchers so far. Based on the present status quo, this paper introduces systematically the preparation methods of photocatalytic coating and influence factors on the photocatalytic capacity and stability of coating for indoor VOCs purification. Then, different photocatalytic coatings are presented and analyzed according to available literatures. In the end, future developments and researches about photocatalytic coating are summarized and proposed.

Abstract:Phthalocyanine (Pc) core with large ring π electron highly conjugated structure has the potential characteristics of self-assembly and has strong absorption in the visible light region. Modified phthalocyanine derivatives have been used in liquid crystal display, solar cells, nonlinear optics and other optoelectronic materials. The behavior of the liquid crystal phase can be changed by modifying the phthalocyanine core. The most representative modification is the central cavity cation coordination of the phthalocyanine core and the addition of a peripheral substituent group. The modified phthalocyanine derivatives have obvious column self-assembly trend, disk mesophase is easy to form, and the electron transmission ability between conjugated layers is enhanced, so they have the basic properties as photoelectric materials. In this paper, the research progress of phthalocyanine derivative discotic liquid crystal materials in the past decade is reviewed, and the structure-activity relationship between the structure modification of phthalocyanine core and its liquid crystal properties is analyzed and summarized. Finally, the defects and research directions of phthalocyanine derivative discoid liquid crystals in the synthesis of high-performance materials are prospected.

Abstract:Polysiloxane has excellent waterproof and antifouling performance and high strength because of its special —Si—O— structure. Moreover, it possesses characteristics of organic polymers and inorganic materials due to its special organic-inorganic structure. Thus, polyssiloxane has outstanding advantages in the field of metal corrosion prevention. Based on the latest research progress on the corrosion resistance of coatings improved by polysiloxane, the anti-corrosion protection properties of polysiloxane coating were summarized from the aspects of molecular structural modification of polysiloxane, decoration by inorganic nanoparticles, hyperbranched polysililoxane and self-repair polysiloxane. And the application of polysiloxane in corrosion prevention was prospected.

Abstract:Poly(3, 4-ethylenedioxythiophene):Polystyrene sulfonate (PEDOT:PSS) has good conductivity and can be easily dispersed in water. Coating the aqueous dispersion onto transparent films can be used to form ion storage layers for electrochromic devices (ECDs). However, the poor water resistance and flexibility of PEDOT:PSS conductive films limit their application in the field of flexible devices. In this paper the flexible hydrophobic molecule isopropylacrylamide (NIPAM) was applied to modify PEDOT:PSS. A series of poly ((styrene sulfonate)-co-isopropylacrylamide) P(SS-co-NIPAM) copolymers with different proportions of NIPAM was prepared, and the conductive polymer PEDOT:P(SS-co-NIPAM) was prepared by oxidative polymerization using P(SS-co-NIPAM) as template. Compared with the unmodified PEDOT:PSS film, when 15% NIPAM (molar fraction, based on the substance content of sodium styrene sulfonate) was added, the transmission rate of the film remained at 81.1%, the water contact angle increased from 18.5° to 39°, the hydrophobicity was improved, and after bending of 1000 times the change of square resistance of the film was 5.71 kΩ/sq , which was much smaller than that of the unmodified PEDOT:PSS film (10.60 kΩ/sq).The optical contrast (ΔT) of the electrochromic devices with PEDOT:P(SS-co-NIPAM) containing 15% NIPAM was 9.83%. After 800 cycles, the ΔT was 9.55%, which was decreased only 0.28%, the attenuation was comparable to that of the devices with unmodified PEDOT:PSS films as ion storage layer. The results indicated that NIPAM improved the flexibility and hydrophobicity of PEDOT:PSS conductive polymer, and the ECD devices using PEDOT:P(SS-co-NIPAM) as ion storage layer could maintain excellent electrochromic performance.

Abstract:The SiO2-coated Fe3O4 composite particles (Fe3O4@SiO2) were prepared, and modified with 3-aminopropyltriethoxysilane (APTES) to prepared aminosilane functionalized magnetic materials (Fe3O4@SiO2-NH2), which were used as carriers for immobilized agarase to produce agarose oligosaccharides. SEM and FTIR characterization results proved that agarase was successfully immobilized on the carrier; VSM characterization results showed that magnetic saturation intensity of Fe3O4@SiO2-NH2 was 48.4 emu/g, and the magnetic saturation intensity of immobilized agarase was 42.8 emu/g, both of them had high magnetic properties. By optimizing the enzyme immobilization conditions, the enzyme activity recovery was 67.74% under the conditions of 7mL enzyme addition,4mL glutaraldehyde addition,2h cross-linking time and 2h immobilization time. Compared with the free agarase, the immobilized agarase had stronger thermal stability and pH stability; moreover, the relative activity of immobilized agarase was 40.41% after 7 applications.

Abstract:In order to improve the service life of the shape-stabilized phase change material (SSPCM), the self-healing temperature-sensitive phase change hydrogels were prepared by free radical polymerization method using water and ionic liquid (IL) as PCM, N-isopropylacrylamide as the monomer, and chitosan (COS) as an additive, and the introduction of 2-ureido-4[1H]-pyrimidinone (UPy) to form a quadruple hydrogen bonds dimer. The chemical structure and micromorphology of the phase change hydrogels were characterized by FTIR, SEM, and TEM, and self-healing, swelling, and thermal properties of the phase change hydrogels were also measured. The results showed that the phase change hydrogel had a porous structure. The internal pore size was 18~38 μm, and the microgel core-shell size was 2~4 μm. The phase change hydrogels showed temperature sensitivity. As the temperature increased, the viscoelasticity of the phase change hydrogel became stronger, which not only maintains the basic shape but also prevents the leakage of the phase change material. The phase change hydrogels had a phase change temperature range from -10 °C to 0 °C. The phase change enthalpy and thermal conductivity of phase change hydrogel could reach up to 252.9 J/g and 0.52 W/(m?K). The rheological experiment indicated that phase change hydrogel (S-EBIL3, the mass ratio of IL to H2O is 3∶10) had a self-healing efficiency of 95.5% within 30 s.

Abstract:Abstract: Superhydrophobic coating is a kind of coating with special wettability on the surface. it has received extensive attention and research because of its excellent performance in the fields of self-cleaning, oil-water separation, antibacterial, anti-corrosion, etc. In this paper, sodium stearate (NaSt) and sodium oleate (NaOL) were used to modify the surface of aragonite and calcite CaCO3 powders, and then the modified CaCO3 powders were blended with polydimethylsiloxane (PDMS) to obtain CaCO3/PDMS based superhydrophobic coatings. The results showed that when the content of NaSt and NaOL was 5% of the substance participating in the reaction, the modification effect of CaCO3 powder was the best, and the hydrophobicity of the prepared CaCO3/PDMS coating was the best. At the same time, the influence of the amount of CaCO3 with different crystal forms on the hydrophobicity of the coating was investigated. The results showed that when the mass ratio of CaCO3 to PDMS was 1.5:1, the contact angle of the CaCO3/PDMS coating was>150°, and the coating was super hydrophobic. The test results of its self-cleaning ability and stability showed that the methylene blue pollutants on the surface of the glass plate coating could be completely washed away with the liquid droplets without residue, and the contact angle was still more than 140°under the impact of 500 mL water with a speed of 5 m/s, which showed the durability and stability of the coating working age.

Abstract:In order to impart leather with multi-functionality and improve its commercial value, composite coating with flame retardant and antibacterial properties was constructed on leather surface by layer-by-layer (LBL) method using biomass materials〔casein (CA), chitosan (CS) , phytic acid (PA)〕and inorganic component magnesium hydroxide (MH) as raw materials. The antibacterial and flame retardant properties of the coated leather were tested. The results showed that the introduction of CS significantly improved the antibacterial performance of as-prepared coatings. When the weight percent of CS was 1.0 %, the coating had excellent antibacterial effect on S. aureus. When the ratio of MH and PA were 1.5 %-0.4 %, impregnated in three layers, the HRR and THR of the coating were reduced by 42.31 % and 40.97 % respectively compared with those of the leather samples without coating, indicating that antibacterial and flame retardant biomass-based coatings was successfully fabricated.

Abstract:In this study, a hydrogel with self-healing properties of hydroxypropyl chitosan/oxidized methyl cellulose (HPC/DAMC) was synthesized by chemical cross-linking Schiff base reaction. Firstly, methyl cellulose was used as raw material to prepare oxidized methyl cellulose by sodium periodate. Then, the amino group of hydroxypropyl chitosan reacted with aldehyde group of oxidized methyl cellulose by Schiff base reaction. The micromorphology, swelling properties, mechanical properties, self-healing properties, in vitro degradation properties and sustained-release properties of hydrogels were studied by adjusting the ratio of HPC and DAMC. With the increase of the ratio of HPC to DAMC, the cross-linking density of HPC/DAMC hydrogel increased, the pores became smaller, and the swelling rate decreased. HPC/DAMC self-healing hydrogels had interconnected pores with pore sizes in the range of 80~375 nm. Under the condition of room temperature without stimulation, HPC/DAMC hydrogels could realize self-healing and have good tensile property within 20 min. HPC/DAMC hydrogel has good water retention, and its swelling ratio is 13~17.Under the action of lysozyme, the biodegradation rate of HPC/DAMC self-healing hydrogel can reach 84.2~99.6% after 60 h.. HPC/DAMC hydrogel had a sustained release effect on anticancer drug gemcitabine, and its sustained release effect was up to 96 h, with a drug release rate of 83.2~92.7%.

Abstract:Self-assembly of colloidal microspheres into ordered arrays is an effective way to prepare structural color materials based on photonic crystals. However, the interaction between microspheres is weak and the structure is easily destroyed by external forces, which is the main obstacle in their practical application. In this article, polyvinylidene fluoride is filled in the gaps of three-dimensional photonic crystals of PS@SiO₂ to lock the ordered arrays benefiting from its mechanical stability and tensile resistance, thus constructing a novel structural color system with stable structure and flexibility. After 100 friction tests, the structure and color of the system remains stable. At the same time, the system is easy to pattern, and has excellent tensile resistance and flexibility. The tensile fracture strength of the system reaches 22.28 MPa, and the fracture strain rate is 28.49%. In addition, the microstructure is still stable after 100 bending tests.

Abstract:A copper-based metal-organic framework, MOF-505, was prepared by solvent-thermal synthesis method, and selected to be used in the extraction oxidation desulfurization system. Its structure and stability were characterized by XRD, FTIR, SEM, XPS and nitrogen adsorption-desorption techniques. The catalytic desulfurization of the simulated oil containing sulfides such as dibenzothiophene (DBT) was investigated, and the sulfur content of was monitored by HPLC. As a result, the optimal conditions were as follows: the volume of DBT simulated oil was 5 mL, the volume of acetonitrile extractant was 5 mL, the volume of hydrogen peroxide was 200 μL, the amount of MOF-505 catalyst was 25 mg, the reaction time was 60 min at 90℃. And the desulfurization rate was up to 95.50% for DBT, 66.88% for benzothiophene (BT) and 78.93% for 4,6-dimethyldibenzothiophene (4,6-DMDBT). After 6 catalytic desulfurization cycles, the catalytic desulfurization rate of MOF-505 for DBT simulated oil remained above 91%, indicating excellent recyclability.

Abstract:Three Cu(II) coordination polymers (CPs), [Cu3(L1)4(OH)2(H2O)2]n (1), [Cu(L2)(OH)]n (2) and [Cu(L2)(CH3O)]n (3), are synthesized by solvothermal method using nicotinate N-oxide (HL1) or isonicotinate N-oxide (HL2) as organic ligands and Cu(OAc)2·H2O as metal salt. Their structures and properties are characterized by single crystal X-ray diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis, thermogravimetric analysis and ultraviolet spectroscopy. CP 1 shows one-dimensional (1D) wavy double chain, CP 2 shows two-dimensional (2D) wavy double layer, CP 3 shows three-dimensional (3D) microporous structure with 1D wavy channels. CPs 1-3 are synthesized under similar solvothermal conditions, but show a multi-dimensional configurations, indicating that the relative position of functional groups in ligand, the coordination mode of ligand and the solvent system all play important roles in the structural diversity of CPs. Thermogravimetric analysis shows that CPs 1-3 have good thermal stability, and the stability is 1 < 2 < 3, indicating that the higher the dimension of CPs 1-3, the better the thermal stability. Nitrotetrazolium blue chloride (NBT) photoreduction test shows that CPs 1-3 have certain superoxide dismutase (SOD) activity, and the activity is 1 > 2 > 3, indicating that the lower the dimension of CPs 1-3, the better the SOD activity. The lower IC50 values of CPs 1 and 2 indicate that they can be used as potential SOD mimetics.

Abstract:Using vermiculite (VMT) as filler and biodegradable polyterephthalate-butanediol ester (PBAT) as matrix, vermiculite/polyterephthalate-butanediol ester (VMT/PBAT) composite films were prepared by melt-blow molding method. VMT/PBAT/SMA composite films were prepared by adding polystyrene maleic anhydride copolymer (SMA) as compatibilizer. The thermal properties, rheological properties, water vapor barrier properties, micro-structure and mechanical properties of pure PBAT films, VMT/PBAT and VMT/PBAT/SMA composite films were tested. The results show that, compared with pure PBAT films, vermiculite filling reduces the thermal stability of VMT/PBAT composite films, and the addition of SMA compatibilizing agent enhances the thermal stability of VMT/PBAT/SMA composite films. The addition of vermiculite reduces the crystallinity of the composite film by about 2%. The water vapor permeability test shows that the water vapor barrier performance of the two composite films conforms to the national standard. The addition of VMT reduced the tensile strength and elongation at break of VMT/PBAT composite film, while the addition of compatibilizer SMA increased the tensile strength and elongation at break of VMT/PBAT composite film by about 10% compared with that of VMT/PBAT composite film.

Abstract:The Z-Scheme heterojunction is extremely attractive in the field of photocatalysis to solve the electron-hole separation transport path because of its unique bi-photon system that can efficiently improve the photocatalytic rate. In this study, the hydrothermal method was used to in situ synthesize two-dimensional/two-dimensional (2D/2D) WO₃/Ag:ZnIn₂S₄ Z-Scheme heterojunction composites. Meanwhile, the microstructure, phase structure, chemical environment and optoelectronic properties of 2D/2D WO₃/Ag:ZnIn₂S₄ Z-Scheme heterojunction composites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflection spectroscopy (UV-Vis DRS), photoelectrochemical (PEC), and photoluminescence (PL) spectra, respectively. Furthermore, under visible light irradiation (using a filter with λ>420 nm), the performance of 2D/2D WO₃/Ag:ZnIn₂S₄ Z-Scheme heterojunction composites for hydrogen production and photodegradation of methyl orange (MO) was assessed. The results show that the photocatalytic performance is also significantly enhanced with the addition of Ag:ZnIn₂S₄ content, in the 2D/2D WO₃/Ag:ZnIn₂S₄ Z-Scheme heterojunction composites. When the mass fraction of Ag:ZnIn₂S₄ was 35.0%, it showed the best hydrogen production rate (158.93 μmol.g_-1^.h_-1^{) and degradation rate (0.18 min_-1}). This work provides new insights into design and construction of Z-scheme heterojunction based on WO₃ nanosheets for visible light catalytic hydrogen production and pollutant degradation.

Abstract:2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one (Acetylformoin) was obtained from furanone via two steps. 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one diacetate (Ⅰ) was synthesized by acetoxylation, and then deacetylated by Novozym435 lipase to synthesize 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one (Ⅱ). The target compound was confirmed by 1H NMR, 13C NMR and HRMS. The thermal pyrolysis behavior of 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one was also investigated using online pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The results indicated that the compound (Ⅱ) synthesized was the target product, and under these optimal conditions, the yield of 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one was above 70%. 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one after pyrolysis could migrates directly into cigarettes, and could also release release aroma substances with scorching sweet aroma, such as DDMP, furanone, maltol and other aromatic components. Adding 0.002% of the target product to cigarettes can significantly improve the flavor. The synthesized product had the functions of enhancing the caramel aroma quality of cigarette smoke and improving aftertaste. There is no significant difference in the hazard index of mainstream cigarette smoke between the cigarettes added with 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one and control, which indicates 2,4-Dihydroxy-2,5-dimethyl-3(2H)-furan-3-one is safe in cigarettes.

Abstract:In order to explore the taste components of sweetening type of yeast extract (YE-S) and their effects on the sweetness of 10 sweeteners, high-performance liquid chromatography and amino acid automatic analyzer was applied to the measurement of free amino acids, 5'- nucleotides and organic acids in yeast extract. To evaluate the contribution of taste components in yeast extract on sweeteners, taste activity value (TAV) was calculated. The results showed that eleven taste components (TAV≥1) were the main components contributing to the taste. The sensory evaluation results showed that 0.1 g/L YE-S significantly improved the sweet taste perception of stevioside, mogroside and sucralose. For stevioside, 0.1 g/L YE-S could shorten the perception time of its maximum sweetness by 2.98 s according to Time-intensity (TI) sensory test. The addition test showed that glutamic acid and alanine can significantly enhance the sweet taste perception of stevioside, mogroside and sucralose, and citric acid can significantly enhance the sweet taste perception of sucralose. Molecular docking results showed that the hydrophobic interactions between stevioside and T1R2 increased in the presence of glutamic acid or alanine. The experiment of enhancing YE-S on the sweetness of 3 sweeteners, which be important theoretical support for the application of yeast extract and the development of sweet food.

Abstract:In order to find antibacterial candidate compounds, on the basis of previous studies, (E)- 2-hydroxy-3-isopentenyl-4-methoxy cinnamic acid (intermediate I) was synthesized through the hydrolysis of osthole under sodium methoxide/ethanol conditions, Then, seventeen target compounds were designed and synthesized by condensation of intermediate I with different amines. The compounds were confirmed by 1HNMR, 13CNMR and MS. The results of antibacterial activities in vitro showed that the derivatives with simplified structure had better antibacterial activities. Among them, the activities of compounds IIh and IIp were the most prominent. The minimum inhibitory concentration (MIC) of the former to S. aureus and MRSA were 16 mg/L and 32 mg/L, respectively. The MIC of the latter to S. aureus and MRSA of were 8 mg/L and 16 mg/L, respectively. The anti-S. aureus activity of the two compounds were close to that of oxacillin, and the anti-MRSA activity were much better than that of oxacillin. It is worth further structural optimization and in-depth study.

Abstract:In order to obtain a new pesticide formulation with high drug loading and good dispersion property, based on drug delivery theory, a pesticide delivery system (PDS) with a special micro/nano composite structure was constructed by electrospinning technology with avermectin (AVM) as the pesticide model, ethyl cellulose (EC) as the main pesticide carrier, and carbomer (CB) as the modified material. Through the exploration of compound proportion, dissolution parameters and spinning conditions, the results show that: The mixed solvent of N, N-dimethylacetamide and ethanol was used to dissolve the carrier material EC and CB. When the volume complex ratio of EC and CB spinning solution was 1:1, the loading rate of AVM in PDS was up to 35.7%, the encapsulation rate of AVM in PDS was close to 100%, and the photolysis resistance was greatly improved. Besides, this PDS has excellent property of water dispersion, long duration of efficacy.

Abstract:Firstly, (S)-2-[(benzyloxycarbonyl)amino]-3-(benzyloxy)propyl phosphonate (Ⅱ) was synthesized after diphenyl phosphite treatment of easily prepared (S)-benzyloxy-2-((benzyloxycarbonyl)amino)-3-hydroxypropanoate (Ⅰ). Secondly, a new compound (R)-2,3-isopropylidene-sn-glyceryl{(S)-2-[(benzyloxycarbonyl)amino]-3-(benzyloxy)-1-oxopropyl}phosph-onate (Ⅳ) was prepared by a one-pot condensation-oxidation procedure. After the pivaloyl chloride mediated activation of compound Ⅱ, condensation with (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanol (Ⅲ), and obtained by iodine mediated oxidation. Then, the protective group of isopropylidene was removed by trifluoroacetic acid (TFA) to obtain the key intermediate, (R)-2,3-dihydroxypropoxy-sn-glyceryl{(S)-2-[(benzyloxycarbonyl)amino]-3-(benzyloxy)-1-oxopropyl}pho-sphonate (Ⅴ). Next, the compound Ⅴ was acetylated further with stearic acid at the function in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) to give (R)-2,3-bis(Stearoyloxy)popyl{(S)-2-[(benzyloxycarbonyl)amino]-3-(benzyloxy)-1-oxopropyl}phosphonate (Ⅵ) with a great yield. Finally, 1,2-distearoyl-sn-glycero-3-phosphatidylserine (Ⅶ) was synthesized by hydrogenolysis of benzyloxycarbonyl (-Cbz) and benzyloxy (-Bn) protective groups. Finally, the main steps were optimized for reaction conditions, and it was verified and amplified. The synthesis of compound Ⅶ was only 5 steps with a total yield of 57.0%. The structure of final compound Ⅶ was confirmed by FTIR, HRMS and NMR

Abstract:The cassava starch as the research object, thermoplastic cassava starch (TPS)/silica (SiO2) composites were prepared by melt blending and molding methods. The effects of different particle sizes (0.02μm、0.2 μm、23 μm) silicon dioxide on the retrogradation melting enthalpy, retrogradation rate, retrogradation index, spherulite morphology, contact angle and thermal stability of thermoplastic cassava starch under ultrasound were studied. The results indicated that comparing with the non-ultrasonic sample, the differential scanning calorimetry (DSC) demonstrated that after ultrasonic treatment, the enthalpy of retrogradation of TPS/SiO2 composites increased, the retrogradation rate enhanced, and the retrogradation index decreased. The retrogradation rate of the product adding 20 nm SiO2 had the largest increase. Polarization (PLM) and water contact angle tests showed that TPS/SiO2 composite spherulite became obvious, and the contact angle increased. TG showed that the ultrasonic action made the moisture of the composite easy to volatilize, the binding ability of glycerol and starch increased, and the molecular structure stability of starch increased. SEM analysis indicated that the silica particles were less aggregated and better dispersed in the matrix under the action of ultrasound. The degree of retrogradation of the composite increased and the double helix structure decreased by FTIR analysis. XRD displayed that the composite presented A+V type crystal formed, and the V type crystal increased and the A type crystal reduced after ultrasonic treatment.

Abstract:In order to reduce the harm of waste water treatment membrane to the environment, this work used biodegradable polymer as the base material to develop the application of environmentally friendly materials in water treatment. For improving the separation efficiency and mechanical performance of the membrane, the chitosan (CS) coating layer and the electrospun polylactic acid (PLA) fiber substrate layer were compounded by dip-coating which formed the CS/PLA filter membrane. On the study of the ratio of CS and PLA, it was found that when the volume ratio of CS to PLA was 7 to 5, the surface of CS coating was dense and flat, and the thickness of CS dense layer was 7 μm. At this time, the pure water flux and mechanical tensile properties of CS/PLA composite membrane were the optimum. The permeability of this composite membrane to acid dye was 99.34 L/(m2?h) and the adsorption rate reached to 96%. The adsorption rates of bovine serum albumin and ovalbumin were 86% and 84%, respectively. The adsorption capacities of composite membrane for Cu2+, Pb2+ and were 165.00, 248.54 and 307.83 mg/g, respectively. The above experimental results provide technical methods and ideas for the application of CS/PLA biomembrane in industrial dye recovery, protein separation with different molecular weight and metal ion removal.

Abstract:Isopentenol polyoxyethylene ether modified graphene oxide (GO-IPEG) was prepared by in situ esterification reaction, and then polycarboxylic modified graphene oxide superplasticizer (GO-PCE) was prepared by GO-IPEG and acrylic acid (AA) using the method of in situ free radical copolymerization. The molecular structure and the dispersion stability of GO-IPEG and GO-PCE were characterized by FTIR, Raman spectra, UV-vis and zeta potential. FTIR results indicate that IPEG was successfully grafted onto the surface of GO by the esterification of carboxyl groups and hydroxyl groups, and then GO-IPEG fabricated with acrylic acid by in situ free radical polymerization. The results of UV-vis and zeta potential show that the the better dispersion properties of GO in polycarboxylic matrix depending on the steric resistance effect of IPEG. The results of cement and concrete show that saturated adsorption can be achieved when the solid content of GO-PCE is 0.15% (by mass of cement), and the fluidity of cement paste can reach 280 mm, the 28 d compressive strength of concrete is 57 MPa, and the 28 d shrinkage rate is 190 × 10-6, and the 28 d electric flux is 1950 C.

Abstract:The graphene oxide modified epoxy resin curing agent (TGO-WPEA) is synthesized by situ polymerization method which firstly form a covalent bond between triethylenetetramine (TETA) and graphene oxide (GO) by ball milling, and then epoxy resin E44, trihydroxymethyl propane triglycidyl ether (TPEG), Methyl polyoxyethylene epoxy ether (MEH) and γ-(2, 3-propylene oxide) propyl trimethoxy silane (KH560) are added successively. Graphene oxide modified waterborne epoxy resin anti-corrosion coating (TGO-EP) is prepared by the combination of TGO-WPEA and epoxy resin emulsion (Epikote-6520). The structure of TGO nanomaterials is characterized by FTIR, XPS and XRD. The corrosion resistance of the composite coating is characterized by electrochemical test and salt spray test, and the physical properties of the coating are tested. The results showed that: the curing agent molecules are covalently linked to the GO surface and the layer spacing of GO is improved. The TGO-EP composite coating prepared by intercalation polymerization has higher anti-corrosion performance. Compared with the pure EP coating, the corrosion potential of TGO-EP composite coating is increased from -0.267 mV to -0.125 mV. The corrosion current density decreased from 5.44×10-8 to 1.09×10-8 A/cm2. The EIS test showed that TGO-EP still had the highest impedance radius and no quadratic time constant after 20 days of immersion.