Hydroxypropyltrimethyl ammonium chloride chitosan(HACC)and hydroxypropyltrimethyl ammonium chloride fully deacetylated chitosan(De-HACC)were synthesized with various degrees of substitution by altering the ratio of ch...Hydroxypropyltrimethyl ammonium chloride chitosan(HACC)and hydroxypropyltrimethyl ammonium chloride fully deacetylated chitosan(De-HACC)were synthesized with various degrees of substitution by altering the ratio of chitosan to glycidyl trimethyl-ammonium chloride(GTMAC).The effects of the quaternary ammonium degree and the acetyl group of these polymers on immunostimulatory activities were detected in RAW 264.7 cells.The expression levels of nitrogen oxide(NO),interleukin-6(IL-6)and tumor necrosis factor(TNF-α)were compared.Results show that the removal of acetyl groups in chitosan obviously improved the degree of substitution of quaternary ammonium salts.In addition,HACC and De-HACC were capable of promoting immunological activity in a substitution-dependent manner;HACC was positively correlated,and De-HACC was negatively correlated.Among tested ratios,HACC-30%and De-HACC-54%performed better than the others,and De-HACC-54%performed the best.Generally,quaternized chitosan possesses immunostimulatory activity,which is related to the degree of quaternization and the acetyl group.展开更多
A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-...A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, (HNMR)-H-1 and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.展开更多
Zirconium-based materials are efficient adsorbent for aqueous phosphate removal.However,current zirconium-based materials still show unsatisfied performance on adsorption capacity and selectivity.Here,we demonstrate a...Zirconium-based materials are efficient adsorbent for aqueous phosphate removal.However,current zirconium-based materials still show unsatisfied performance on adsorption capacity and selectivity.Here,we demonstrate a zirconium hydroxide encapsulated in quaternized cellulose(QC-Zr) for the selective phosphate removal.Zirconium hydroxide nanoparticles were simultaneously generated in situ with the QC framework and firmly anchored in the three-dimensional(3D) cross-linked cellulose chains.The maximum P adsorption capacity of QC-Zr was 83.6 mg P/g.Furthermore,the QC-Zr shows high P adsorption performance in a wide pH range,generally due to the electrostatic effects of quaternized cellulose.The enhanced adsorption of P was also achieved in the presence of competing anions(including Cl^-,NO3^-,SO4^2-,SO4^4-) and humic acid(HA) even at a molar ratio up to 20 levels.The column adsorption capacity of QC-Zr reached 4000 bed volumes(BV) at EBCT=0.5 min as the P concentration decreased from 2.5 to 0.5 mg/L.Mechanism study revealed that both-N^+(CH3)3 groups and zirconium hydroxide were involved in phosphate adsorption via electrostatic interactions between -N^+(CH3)3 and phosphate,and the formation of zirconium hydrogen phosphate(Zr(HPO4)x).The 31 P nuclear magnetic resonance(NMR) study implied that P surface-precipitated and inner-sphere complexed with zirconium hydroxide at a ratio of 3:1.展开更多
Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chlorometh...Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.展开更多
Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan （hyd...Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan （hydroxypropyltrimethyl ammonium chloride chitosan, HACC）, could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes （NT-H）. The titanium implant （Ti）, nanotubes without polymer loading （NT）, and nanotubes loaded with chitosan （NT-C） were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro. The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methiciUin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.展开更多
Amphiphilic graft copolymers consisting of poly（vinyl chloride）（PVC） main chains and poly（4-vinyl pyridine）（P4VP） side chains were synthesized via atom transfer radical polymerization（ATRP） using direct init...Amphiphilic graft copolymers consisting of poly（vinyl chloride）（PVC） main chains and poly（4-vinyl pyridine）（P4VP） side chains were synthesized via atom transfer radical polymerization（ATRP） using direct initiation of chlorine atoms. The successful synthesis of PVC-g-P4 VP graft copolymers was confirmed by Fourier transform infrared spectroscopy（FTIR） and proton nuclear magnetic resonance（1H-NMR）. Transmission electron microscope（TEM） and small angle X-ray scattering（SAXS） analysis showed that PVC-g-P4 VP exhibited microphase-separated, ordered structure with 37.6 nm of domain spacing, which was not observed in neat PVC. For antibacterial applications, the tertiary nitrogen atoms of PVC-gP4 VP was quaternized using 1-bromohexane, as confirmed by FTIR measurements. Bacteria including Escherichia coli（E. coli）, Staphylococcus aureus（S. aureus）, Bacillus cereus（B. cereus）, and Pseudomonas aeruginosa（P. aeruginosa） were completely killed in 24 h on the quaternized PVC-g-P4VP（46% grafting） surface, indicating its excellent antibacterial behavior while it showed to be cytotoxic to mammalian cell.展开更多
This article is a preliminary study on antibacterial blends of polycaprolactone,chitosan and quaternized chitosan by melt processing.Blends were characterized,mechanical test and antibacterial evaluation against Esche...This article is a preliminary study on antibacterial blends of polycaprolactone,chitosan and quaternized chitosan by melt processing.Blends were characterized,mechanical test and antibacterial evaluation against Escherichia coli and Staphylococcus aureus,were conducted.Results showed that the antibacterial potential of chitosan was limited in blends and polycaprolactone/chitosan did not show significant antibacterial effect compared with neat polycaprolactone(PCL).Inhibition rates of polycaprolactone/quaternized chitosan were 39.2%99.9%against Escherichia coli,while inhibition rate was 40.9%99.9%against Staphylococcus aureus.When quaternized chitosan(QCTS)content was up to 20%,blends exhibited 99.9%inhibition rates against both two types of bacteria.展开更多
For the purpose of alleviating the adverse effect of paste aging on the properties of corn starch film, a series of electroneutrally quaternized/sulfosuccinylated starches（EQSS） with different degrees of substitutio...For the purpose of alleviating the adverse effect of paste aging on the properties of corn starch film, a series of electroneutrally quaternized/sulfosuccinylated starches（EQSS） with different degrees of substitution（DS） were synthesized via the quaternization/sulfosuccination of acid-thinned corn starch（ATS） by varying the amounts of N-（3-chloro-2-hydroxypropl） trimethylammonium chloride, maleic anhydride, and sodium hydrogen sulfite. The influence of paste aging on the properties of starch film cast from heat-induced starch paste was investigated and the properties were explored in terms of tensile strength, elongation, work at break, degree of crystallinity, and flex-fatigue resistance. The experimental results showed that the paste ageing generated adverse influence on the elongation, work at break, and flex-fatigue resistance of starch film. Further experiments showed that electroneutral quaternization/sulfosuccination of starch were able to alleviate the negative effect of paste ageing on the elongation, work at break, and flex-fatigue resistance, thereby obviously enhancing the elongation, work at break and flex-fatigue resistance, and thus reducing the drawback of brittleness. The enhancement depended on the amounts of the substituents introduced. With the increase in DS value, the elongation and work at break as well as flex-fatigue resistance continuously rose, whereas the tensile strength gradually reduced.展开更多
Trauma and neurosurgery often result in dural defects and are followed by serious complications or even death, finding suitable dural replacement materials to repair the defective dura has important clinical significa...Trauma and neurosurgery often result in dural defects and are followed by serious complications or even death, finding suitable dural replacement materials to repair the defective dura has important clinical significance. Porcine peritoneal acellular matrix(PPAM) is a promising alternative material, but its poor stability makes it difficult to meet the various needs of dural reconstruction. In this work, we developed a novel antibacterial cross-linking agent oxidized quaternized guar gum(OQGG) and used it for the first time to stabilize PPAM to construct a dural mater substitute(OQGG-PPAM). The results showed that 1.5%OQGG-PPAM presented suitable mechanical property as well as good thermal stability and resistance to enzymatic degradation. It also exhibited good antibacterial activity and good anti-leakage ability. Furthermore, 1.5% OQGG-PPAM not only exhibited excellent cell compatibility but also significantly stimulated the secretion of b FGF and VEGF from seeded cells which was convenient for dural remodeling. In vivo experiment, it also exhibited the excellent histocompatibility and good anti-adhesion property. This study showed that OQGG can be used as a novel antibacterial cross-linking reagent for crosslinking natural tissues and 1.5% OQGG-PPAM was a potential candidate material for dura mater substitute.展开更多
Quaternized cellulose( QC) derivatives were synthesized by reacting cellulose with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHPTAC) in an aqueous solution of Na OH-urea. The chemical structures and physic...Quaternized cellulose( QC) derivatives were synthesized by reacting cellulose with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHPTAC) in an aqueous solution of Na OH-urea. The chemical structures and physical properties of the obtained QC derivatives were characterized using nitrogen content analysis,Fourier transform infrared spectroscopy( FT-IR),~1H-nuclear magnetic resonance(1H-NMR),X-ray diffraction( XRD),and thermal gravity analysis( TGA). The FT-IR and ~1H-NMR results confirmed the successful introduction of cationic quaternary ammonium groups into the main chain of cellulose. A series of QC derivatives with the degree of substitution( DS) values ranging from 0. 33 to 0. 80 were derived by adjusting the molar ratio of CHPTAC to anhydroglucose unit( AGU) of cellulose,concentration of cellulose in the Na OH-urea solution,as well as reaction temperature and time. According to the DS values of the QC derivatives,the optimized synthetic conditions were as follows: 25℃ reaction temperature,3% cellulose in Na OH-urea solution,the molar ratio of etherification agent to glycosidic cellulose of 15∶ 1,and 12 h reaction time. The TGA and XRD results revealed that the crystalline structure was destroyed during etherification,and the thermal stability of the QC derivatives was lower than that of cellulose.展开更多
Lithium–sulfur (Li–S) batteries are great candidates for energy storage systems, but need to overcome theissues of low sulfur utilization and polysulfide shuttling for use in large-scale commercial applications.Rece...Lithium–sulfur (Li–S) batteries are great candidates for energy storage systems, but need to overcome theissues of low sulfur utilization and polysulfide shuttling for use in large-scale commercial applications.Recently, quaternized polymers have received much attention for their polysulfide trapping propertiesdue to electrostatic interaction. In this work, we report a series of polyarylether sulfone (PSF) binderswith different cation structures including imidazolium (Im), triethylammonium (Tr), and morpholinium(Mo). The ability of the these quaternized binders and the conventional poly(vinylidene fluoride) or PVDFbinder to capture polysulfide increases in the order of PVDF << PSF-Mo < PSF-Tr< PSF-Im. The delocalizedcharge on the imidazolium cation may promote the interaction between PSF-Im and polysulfide asindicated by an X-ray photoelectron spectroscopic study. The PSF-Im based cathodes showed the highestcapacity retention (77% at 0.2 C after 100 cycles and 84% at 0.5 C after 120 cycles), and the bestrate capability. This work demonstrates the importance of the cation structure in the design of efficientquaternized binders for high performance Li–S batteries.展开更多
An approach for preparation of a novel composite anion exchanger composed of polystyrene/divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by t...An approach for preparation of a novel composite anion exchanger composed of polystyrene/divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by the condensation polymerization between methylamine (MA) and 1,4-butanediol diglycidyl ether (BDDE), which were characterized by Fourier transform infrared (FTIR) spectra, X-ray phtoelectron spectroscopy (XPS), thermogravimetric analysis (TGA). QND with layers of cationic polyelectrolyte was attached onto the surface of sulfonated PS/DVB beads electrostatically. Subsequently, hyperbranched reaction of QND agglomerated on the PS/DVB bead surface was performed by the alternate reaction between MA and BDDE to increase the exchange capacity. The composite anion exchanger showed good stability in organic solvent and a wide pH range.The surface of these microspheres was characterized by scanning electron microscopy. In addition, ion exchange selectivity and separation efficiency of the anion exchangers were assessed using the mixtures of anions (F,Cl,NO_2,Br,NO_3,HPO_4~2 and SO_4~2) with carbonate/bicarbonate as eluent, and the anion exchanger with high exchange capacity could be used to analyze chloride in aqueous solution with high concentration of fluoride. This work explores the potential of nanodiamods as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions.展开更多
Three quatemized chitosan derivatives were synthesized and their adsorption performance of bile acid from aqueous solution was studied. The adsorption capacities and rates of bile acid onto quatemized chitosan derivat...Three quatemized chitosan derivatives were synthesized and their adsorption performance of bile acid from aqueous solution was studied. The adsorption capacities and rates of bile acid onto quatemized chitosan derivatives were evaluated. The kinetic experimental data properly correlated with the second-order kinetic model, which indicated that the chemical sorption is the rate-limiting step. The results showed that the quatemized chitosan derivatives are favorable adsorbents for bile acid.展开更多
The paper describes some properties of new quaternized polysulfones obtained by quaternization of chloromethylated polysulfone with different tertiary amines - N,N-dimethylethylamine and N,N-dimethyloctylamine. Hydrop...The paper describes some properties of new quaternized polysulfones obtained by quaternization of chloromethylated polysulfone with different tertiary amines - N,N-dimethylethylamine and N,N-dimethyloctylamine. Hydrophilic/hydrophobic properties, morphological aspects and compatibility with red blood cells and platelets are affected by the alkyl radicals and by history of the formed films. The results obtained are useful in biomedical applications, including evaluation of bacterial adhesion to the surfaces, or utilization of modified polysulfones as semipermeable membranes.展开更多
Ion-molecular reactions of nucleogenic phenyl cations with the nucleophilic centers of 1,4-diazines have been investigated for the first time. Previously unknown tritium labeled N-phenyl quaternary derivatives of pyra...Ion-molecular reactions of nucleogenic phenyl cations with the nucleophilic centers of 1,4-diazines have been investigated for the first time. Previously unknown tritium labeled N-phenyl quaternary derivatives of pyrazine and quinoxaline, which are potential radioactive biomarkers, have been obtained by nuclear-chemical method.展开更多
The efficient separation of fission products,such as TcO_(4)^(-)and I^(-),holds strategic significance for the management of radioactive wastes and environmental protection.In this study,we propose an ultrafast strate...The efficient separation of fission products,such as TcO_(4)^(-)and I^(-),holds strategic significance for the management of radioactive wastes and environmental protection.In this study,we propose an ultrafast strategy for scalable preparation of a highly quaternized organic network to facilitate efficient and synchronous separation of iodide and pertechnetate.The network can be prepared within a few minutes at room temperature,using polyethylenimine and 1,2,4,5-tetrakis(bromomethyl)benzene as building blocks.After chlorine replacement,the network,abundantly decorated with quaternary ammonium groups(Cl@QPN),exhibits an ultrahigh positive charge density of 7.6 mmol/g.This enables the rapid and efficient enrichment of target anions through strong electrostatic Coulomb interactions.As a result,Cl@QPN exhibits significantly higher adsorption rate constants of 0.830 g/(mg min)for ReO_(4)^(-)(a nonradioactive surrogate of TcO_(4)^(-))and 0.677 g/(mg min)for I-compared to other materials.Furthermore,it possesses high adsorption capacities,reaching 1,681 mg/g for ReO_(4)^(-)and 917.4 mg/g for I-.Cl@QPN also demonstrates good selectivity towards target ions and shows efficient adsorption for^(99)TcO_(4)^(-).Additionally,Cl@QPN exhibits high dynamic processing capacities,handling up to 3,100 and 7,400 kg of simulated streams per kilogram of material for I-and ReO_(4)^(-),respectively.展开更多
背景:季铵化壳聚糖具有良好的凝血机制、水溶性及抗菌性,在止血领域具有广阔的应用前景。目的:综述季铵化壳聚糖的合成方法、止血机制与应用研究进展。方法:采用计算机检索万方、Pub Med、Web of science数据库中的相关文献,中文检索词...背景:季铵化壳聚糖具有良好的凝血机制、水溶性及抗菌性,在止血领域具有广阔的应用前景。目的:综述季铵化壳聚糖的合成方法、止血机制与应用研究进展。方法:采用计算机检索万方、Pub Med、Web of science数据库中的相关文献,中文检索词为“壳聚糖,季铵化,止血,止血材料,水凝胶,纳米材料”;英文检索词为“Chitosan,Quaternized chitosan,Hemostasis,Hemostasis material,Hydrogel,Nanostructures”。通过阅读文题和摘要进行初步筛选,排除与文章主题不相关的文献,最终纳入62篇文献进行综述。结果与结论:季铵化壳聚糖的阳离子特性、黏附能力和生物活性共同驱动多维度止血机制在紧急止血领域展现出独特的材料优势,其效能不仅依赖于物理性吸附血液水分、浓缩凝血因子以加速血块形成(吸附作用),还通过电荷诱导红细胞聚集、激活血小板黏附与活化通路协同增强凝血级联反应。季铵基团赋予壳聚糖的抗菌性能可进一步降低感染风险,为创伤愈合提供双重保障。采用物理化学方法制备季铵化壳聚糖壳聚糖粉末、海绵、水凝胶和纳米复合材料,可进一步提升材料的止血效能。季铵化壳聚糖止血材料在体外实验和动物模型中表现出良好的止血效果和生物相容性,但目前缺乏足够的临床试验数据来验证其在人体中的安全性和有效性。展开更多
Based on our previous report on N-alkylpyridinium isotope quaternization （NAPIQ） for the analysis of alcoholic and α,β-unsaturated ketone compounds, we have further applied NAPIQ method in the screening of hair li...Based on our previous report on N-alkylpyridinium isotope quaternization （NAPIQ） for the analysis of alcoholic and α,β-unsaturated ketone compounds, we have further applied NAPIQ method in the screening of hair lipids in drug abusers. Relative isotopic quantification was used for comparison of fatty alcohols between normal and drug abuse group, The NAPIQ strategy was proven to be a high-throughput method in the metabolic comparison studies of different group samples. The attached N-cationic pyridinium significantly improved the detection sensitivity for these fatty alcohols in matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometric （MALDI-FTMS） analysis. The experimental results showed that the levels of fatty alcohols in the hair of heroin abuse group decreased significantly compared with the normal groups, which may be the results of the inducing of peroxidation enzyme. NAPIQ was proven to be an effective and alternative method in the research of fatty alcoholic metabolism for drug abuse monitoring.展开更多
Cellulose nanofibers(CNF)are considered to be a potential substrate of energy material for energy storage devices due to the foldable,lightweight,recyclable and environmentally friendly feature.However,the energy mate...Cellulose nanofibers(CNF)are considered to be a potential substrate of energy material for energy storage devices due to the foldable,lightweight,recyclable and environmentally friendly feature.However,the energy materials tend to distribute unevenly or fall off from CNF easily,resulting in the decrease of the devices’overall performance.Here,for the first time,we used quaternized chitosan(QCS)as stabilizer and adhesive to in situ synthesize and deposite copper sulfide nanocrystals(CuS-NCs)on CNF and further obtained the conductive paper for flexible supercapacitors.In the presence of QCS,CuS-NCs deposited in situ on CNF can be capped and stabilized by the QCS molecular chains for uniform distribution,which is conducive to the capacitive behavior and electrochemical stability of composite paper.The result shows that the specific capacitance of the composite paper was as high as 314.3 F/g at a current density of 1 A/g,a high rate capacitance of 252.6 F/g was achieved even at a high current density of 10 A/g.It reveals that the composite paper exhibited better electrochemical performance than many other CuS-based electrode materials for supercapacitor.More importantly,the composite paper performed well in various folding state without changing much electrochemical performance.Therefore,this work provides a novel strategy to in situ fabricate paper-based electrode for nextgeneration flexible energy-storage system.展开更多
Innovative biomedical applications have high requirements for biomedical materials.Herein,a series of biocompatible,antibacterial and hemostatic sponges were successfully fabricated for the treatment of acute upper ga...Innovative biomedical applications have high requirements for biomedical materials.Herein,a series of biocompatible,antibacterial and hemostatic sponges were successfully fabricated for the treatment of acute upper gastrointestinal bleeding(AUGB).Quaternized chitosan(QC)and soy protein isolate(SPI)were chemically cross-linked to obtain porous SPI/QC sponges(named SQS-n,with n¼30,40,50 or 60 corresponding to the weight percentage of the QC content).The chemical composition,physical properties and biological activity of SQS-n were investigated.SQS-n could support the adhesion and proliferation of L929 cells while triggering no obvious blood toxicity.Meanwhile,SQS-n exhibited good broad-spectrum antibacterial activity against both grampositive bacteria(Staphylococcus aureus)and gram-negative bacteria(Escherichia coli).The in vivo hemostatic effect of SQS-n was evaluated using three different bleeding models.The results revealed that SQS-50 performed best in reducing blood loss and hemostatic time.The overall hemostatic effect of SQS-50 was comparable to that of a commercial gelatin sponge.The enhanced antibacterial and hemostatic activities of SQS-n were mainly attributed to the QC component.In conclusion,this work developed a QC-functionalized hemostatic sponge that is highly desirable for innovative biomedical applications,such as AUGB.展开更多
基金*Supported by Key Deployment Projects of the Marine Science Research Center of Chinese Academy of Sciences(No.COMS2020J04)。
文摘Hydroxypropyltrimethyl ammonium chloride chitosan(HACC)and hydroxypropyltrimethyl ammonium chloride fully deacetylated chitosan(De-HACC)were synthesized with various degrees of substitution by altering the ratio of chitosan to glycidyl trimethyl-ammonium chloride(GTMAC).The effects of the quaternary ammonium degree and the acetyl group of these polymers on immunostimulatory activities were detected in RAW 264.7 cells.The expression levels of nitrogen oxide(NO),interleukin-6(IL-6)and tumor necrosis factor(TNF-α)were compared.Results show that the removal of acetyl groups in chitosan obviously improved the degree of substitution of quaternary ammonium salts.In addition,HACC and De-HACC were capable of promoting immunological activity in a substitution-dependent manner;HACC was positively correlated,and De-HACC was negatively correlated.Among tested ratios,HACC-30%and De-HACC-54%performed better than the others,and De-HACC-54%performed the best.Generally,quaternized chitosan possesses immunostimulatory activity,which is related to the degree of quaternization and the acetyl group.
文摘A series of N-alkyl or N-aryl chitosan quaternary ammonium salts were prepared via Schiffs base intermediates. Quaternization of N-substituted chitosan derivatives was carried out using methyl iodide to produce water-soluble cationic chitosan quaternary ammonium salt. The products were characterized by IR, (HNMR)-H-1 and elemental analysis. The degree of substitution of chitosan quaternary ammonium salt was calculated by elemental analysis.
基金supported by the National Natural Science Foundation of China (Nos.51738013 and 51438011)the National Science and Technology Major Project of China (No. 2017ZX07202003)the Chinese Postdoctoral Science Foundation (No.043211001).
文摘Zirconium-based materials are efficient adsorbent for aqueous phosphate removal.However,current zirconium-based materials still show unsatisfied performance on adsorption capacity and selectivity.Here,we demonstrate a zirconium hydroxide encapsulated in quaternized cellulose(QC-Zr) for the selective phosphate removal.Zirconium hydroxide nanoparticles were simultaneously generated in situ with the QC framework and firmly anchored in the three-dimensional(3D) cross-linked cellulose chains.The maximum P adsorption capacity of QC-Zr was 83.6 mg P/g.Furthermore,the QC-Zr shows high P adsorption performance in a wide pH range,generally due to the electrostatic effects of quaternized cellulose.The enhanced adsorption of P was also achieved in the presence of competing anions(including Cl^-,NO3^-,SO4^2-,SO4^4-) and humic acid(HA) even at a molar ratio up to 20 levels.The column adsorption capacity of QC-Zr reached 4000 bed volumes(BV) at EBCT=0.5 min as the P concentration decreased from 2.5 to 0.5 mg/L.Mechanism study revealed that both-N^+(CH3)3 groups and zirconium hydroxide were involved in phosphate adsorption via electrostatic interactions between -N^+(CH3)3 and phosphate,and the formation of zirconium hydrogen phosphate(Zr(HPO4)x).The 31 P nuclear magnetic resonance(NMR) study implied that P surface-precipitated and inner-sphere complexed with zirconium hydroxide at a ratio of 3:1.
基金partly financed by the Major State Basic Research Development Program of China(No.2003 CB615700)the National Natural Science Foundation of China(No.20604005).
文摘Chloromethylated poly（phthalazinone ether sulfone ketone） （CMPPESK） was prepared from poly（phthalazinone ether sulfone ketone） （PPESK） using chloromethyl octyl ethers （CMOE） with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone （NMP）, N,N-dimethylacetamide （DMAc） and chloroform. Quaternized poly（phthalazinone ether sulfone ketone） （QAPPESK） was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance, which was only partly soluble in sulfuric acid （98%） and swollen in N,N-dimethylformamide （DMF）. The vanadium redox flow battery （V-RFB） using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.
基金financially supported by the National Natural Science Foundation of China (No.31271015,81501856)National Key R&D Program (2016YFC1102100)+1 种基金Shanghai Science and Technology Development Fund (13JC1403900,13DZ2294000)Medical Engineering Collaborative Project of Shanghai Jiao Tong University (YG2014ZD01)
文摘Infection is one of the major causes of failure of orthopedic implants. Our previous study demonstrated that nanotube modification of the implant surface, together with nanotubes loaded with quaternized chitosan （hydroxypropyltrimethyl ammonium chloride chitosan, HACC）, could effectively inhibit bacterial adherence and biofilm formation in vitro. Therefore, the aim of this study was to further investigate the in vitro cytocompatibility with osteogenic cells and the in vivo anti-infection activity of titanium implants with HACC-loaded nanotubes （NT-H）. The titanium implant （Ti）, nanotubes without polymer loading （NT）, and nanotubes loaded with chitosan （NT-C） were fabricated and served as controls. Firstly, we evaluated the cytocompatibility of these specimens with human bone marrow-derived mesenchymal stem cells in vitro. The observation of cell attachment, proliferation, spreading, and viability in vitro showed that NT-H has improved osteogenic activity compared with Ti and NT-C. A prophylaxis rat model with implantation in the femoral medullary cavity and inoculation with methiciUin-resistant Staphylococcus aureus was established and evaluated by radiographical, microbiological, and histopathological assessments. Our in vivo study demonstrated that NT-H coatings exhibited significant anti-infection capability compared with the Ti and NT-C groups. In conclusion, HACC-loaded nanotubes fabricated on a titanium substrate show good compatibility with osteogenic cells and enhanced anti-infection ability in vivo, providing a good foundation for clinical application to combat orthopedic implant-associated infections.
基金financially supported by a National Research Foundation(NRF)grant funded by the Korean government(MEST)through the Core Research Program(2012R1A2A2A02011268)Agriculture Research Center program of Ministry for Food,Agriculture,Forestry,and Fisheries(IPET 112051-3)the Korea CCS R&D Center and the Energy Efficiency&Resources of the Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Ministry of Knowledge Economy(20122010100040)
文摘Amphiphilic graft copolymers consisting of poly（vinyl chloride）（PVC） main chains and poly（4-vinyl pyridine）（P4VP） side chains were synthesized via atom transfer radical polymerization（ATRP） using direct initiation of chlorine atoms. The successful synthesis of PVC-g-P4 VP graft copolymers was confirmed by Fourier transform infrared spectroscopy（FTIR） and proton nuclear magnetic resonance（1H-NMR）. Transmission electron microscope（TEM） and small angle X-ray scattering（SAXS） analysis showed that PVC-g-P4 VP exhibited microphase-separated, ordered structure with 37.6 nm of domain spacing, which was not observed in neat PVC. For antibacterial applications, the tertiary nitrogen atoms of PVC-gP4 VP was quaternized using 1-bromohexane, as confirmed by FTIR measurements. Bacteria including Escherichia coli（E. coli）, Staphylococcus aureus（S. aureus）, Bacillus cereus（B. cereus）, and Pseudomonas aeruginosa（P. aeruginosa） were completely killed in 24 h on the quaternized PVC-g-P4VP（46% grafting） surface, indicating its excellent antibacterial behavior while it showed to be cytotoxic to mammalian cell.
基金the Science Foundations from Department of Education,Fujian Province,China(JZ180899).
文摘This article is a preliminary study on antibacterial blends of polycaprolactone,chitosan and quaternized chitosan by melt processing.Blends were characterized,mechanical test and antibacterial evaluation against Escherichia coli and Staphylococcus aureus,were conducted.Results showed that the antibacterial potential of chitosan was limited in blends and polycaprolactone/chitosan did not show significant antibacterial effect compared with neat polycaprolactone(PCL).Inhibition rates of polycaprolactone/quaternized chitosan were 39.2%99.9%against Escherichia coli,while inhibition rate was 40.9%99.9%against Staphylococcus aureus.When quaternized chitosan(QCTS)content was up to 20%,blends exhibited 99.9%inhibition rates against both two types of bacteria.
基金Funded by the Open Project Program of Key Laboratory of Eco-Textiles,Ministry of Education,China(No.KLET0617)the Scientific Research Fund of Talent Introduction of Anhui Polytechnic University(No.2016YQQ004)
文摘For the purpose of alleviating the adverse effect of paste aging on the properties of corn starch film, a series of electroneutrally quaternized/sulfosuccinylated starches（EQSS） with different degrees of substitution（DS） were synthesized via the quaternization/sulfosuccination of acid-thinned corn starch（ATS） by varying the amounts of N-（3-chloro-2-hydroxypropl） trimethylammonium chloride, maleic anhydride, and sodium hydrogen sulfite. The influence of paste aging on the properties of starch film cast from heat-induced starch paste was investigated and the properties were explored in terms of tensile strength, elongation, work at break, degree of crystallinity, and flex-fatigue resistance. The experimental results showed that the paste ageing generated adverse influence on the elongation, work at break, and flex-fatigue resistance of starch film. Further experiments showed that electroneutral quaternization/sulfosuccination of starch were able to alleviate the negative effect of paste ageing on the elongation, work at break, and flex-fatigue resistance, thereby obviously enhancing the elongation, work at break and flex-fatigue resistance, and thus reducing the drawback of brittleness. The enhancement depended on the amounts of the substituents introduced. With the increase in DS value, the elongation and work at break as well as flex-fatigue resistance continuously rose, whereas the tensile strength gradually reduced.
基金financially supported by the National Key Research and Development Program of China(Nos.2016YFC1100900,2016YFC1100901,2016YFC1100903 and 2016YFC1100904)the Key Research and Development Program of Sichuan Province(No.2019YFS0121)。
文摘Trauma and neurosurgery often result in dural defects and are followed by serious complications or even death, finding suitable dural replacement materials to repair the defective dura has important clinical significance. Porcine peritoneal acellular matrix(PPAM) is a promising alternative material, but its poor stability makes it difficult to meet the various needs of dural reconstruction. In this work, we developed a novel antibacterial cross-linking agent oxidized quaternized guar gum(OQGG) and used it for the first time to stabilize PPAM to construct a dural mater substitute(OQGG-PPAM). The results showed that 1.5%OQGG-PPAM presented suitable mechanical property as well as good thermal stability and resistance to enzymatic degradation. It also exhibited good antibacterial activity and good anti-leakage ability. Furthermore, 1.5% OQGG-PPAM not only exhibited excellent cell compatibility but also significantly stimulated the secretion of b FGF and VEGF from seeded cells which was convenient for dural remodeling. In vivo experiment, it also exhibited the excellent histocompatibility and good anti-adhesion property. This study showed that OQGG can be used as a novel antibacterial cross-linking reagent for crosslinking natural tissues and 1.5% OQGG-PPAM was a potential candidate material for dura mater substitute.
基金financially supported by grants from the National Natural Science Foundation of China(No.31500493)the Liaoning Educational Common Scientific Research Project(No.L2015044)+1 种基金the Liaoning Natural Science Foundation(No.2015020576)the Open Foundation of the Key Lab of Pulp and Paper Science & Technology,and Ministry of Education(Shandong Province),Qilu University of Technology(No.08031338)
文摘Quaternized cellulose( QC) derivatives were synthesized by reacting cellulose with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHPTAC) in an aqueous solution of Na OH-urea. The chemical structures and physical properties of the obtained QC derivatives were characterized using nitrogen content analysis,Fourier transform infrared spectroscopy( FT-IR),~1H-nuclear magnetic resonance(1H-NMR),X-ray diffraction( XRD),and thermal gravity analysis( TGA). The FT-IR and ~1H-NMR results confirmed the successful introduction of cationic quaternary ammonium groups into the main chain of cellulose. A series of QC derivatives with the degree of substitution( DS) values ranging from 0. 33 to 0. 80 were derived by adjusting the molar ratio of CHPTAC to anhydroglucose unit( AGU) of cellulose,concentration of cellulose in the Na OH-urea solution,as well as reaction temperature and time. According to the DS values of the QC derivatives,the optimized synthetic conditions were as follows: 25℃ reaction temperature,3% cellulose in Na OH-urea solution,the molar ratio of etherification agent to glycosidic cellulose of 15∶ 1,and 12 h reaction time. The TGA and XRD results revealed that the crystalline structure was destroyed during etherification,and the thermal stability of the QC derivatives was lower than that of cellulose.
基金supported by the Science and Technology Innovation Fund of Dalian(2018J12GX052)the National Natural Science Foundation of China(Grant No.21776042)the Fundamental Research Funds for the Central Universities of China(Grant no.DUT19ZD214)。
文摘Lithium–sulfur (Li–S) batteries are great candidates for energy storage systems, but need to overcome theissues of low sulfur utilization and polysulfide shuttling for use in large-scale commercial applications.Recently, quaternized polymers have received much attention for their polysulfide trapping propertiesdue to electrostatic interaction. In this work, we report a series of polyarylether sulfone (PSF) binderswith different cation structures including imidazolium (Im), triethylammonium (Tr), and morpholinium(Mo). The ability of the these quaternized binders and the conventional poly(vinylidene fluoride) or PVDFbinder to capture polysulfide increases in the order of PVDF << PSF-Mo < PSF-Tr< PSF-Im. The delocalizedcharge on the imidazolium cation may promote the interaction between PSF-Im and polysulfide asindicated by an X-ray photoelectron spectroscopic study. The PSF-Im based cathodes showed the highestcapacity retention (77% at 0.2 C after 100 cycles and 84% at 0.5 C after 120 cycles), and the bestrate capability. This work demonstrates the importance of the cation structure in the design of efficientquaternized binders for high performance Li–S batteries.
基金financially supported by the National Natural Science Foundation of China (No. 51503182)Analysis and Measurement Foundation of Zhejiang Province(No. 2017C37064)+1 种基金Zhejiang Provincial Natural Science Foundation (No. LQ15C200006)Zhejiang University of Technology Natural Science Foundation (No. 2014XY002)
文摘An approach for preparation of a novel composite anion exchanger composed of polystyrene/divinylbenzene (PS/DVB) beads and quaternized nanodiamods (QND) were proposed. Oxidized nanodiamonds (OND) were quaternized by the condensation polymerization between methylamine (MA) and 1,4-butanediol diglycidyl ether (BDDE), which were characterized by Fourier transform infrared (FTIR) spectra, X-ray phtoelectron spectroscopy (XPS), thermogravimetric analysis (TGA). QND with layers of cationic polyelectrolyte was attached onto the surface of sulfonated PS/DVB beads electrostatically. Subsequently, hyperbranched reaction of QND agglomerated on the PS/DVB bead surface was performed by the alternate reaction between MA and BDDE to increase the exchange capacity. The composite anion exchanger showed good stability in organic solvent and a wide pH range.The surface of these microspheres was characterized by scanning electron microscopy. In addition, ion exchange selectivity and separation efficiency of the anion exchangers were assessed using the mixtures of anions (F,Cl,NO_2,Br,NO_3,HPO_4~2 and SO_4~2) with carbonate/bicarbonate as eluent, and the anion exchanger with high exchange capacity could be used to analyze chloride in aqueous solution with high concentration of fluoride. This work explores the potential of nanodiamods as an agglomerated material for ion chromatography stationary phases for the separation of inorganic anions.
基金This project is supported by the Natural Science Foundation of Tianjin （No. 043610611）
文摘Three quatemized chitosan derivatives were synthesized and their adsorption performance of bile acid from aqueous solution was studied. The adsorption capacities and rates of bile acid onto quatemized chitosan derivatives were evaluated. The kinetic experimental data properly correlated with the second-order kinetic model, which indicated that the chemical sorption is the rate-limiting step. The results showed that the quatemized chitosan derivatives are favorable adsorbents for bile acid.
文摘The paper describes some properties of new quaternized polysulfones obtained by quaternization of chloromethylated polysulfone with different tertiary amines - N,N-dimethylethylamine and N,N-dimethyloctylamine. Hydrophilic/hydrophobic properties, morphological aspects and compatibility with red blood cells and platelets are affected by the alkyl radicals and by history of the formed films. The results obtained are useful in biomedical applications, including evaluation of bacterial adhesion to the surfaces, or utilization of modified polysulfones as semipermeable membranes.
文摘Ion-molecular reactions of nucleogenic phenyl cations with the nucleophilic centers of 1,4-diazines have been investigated for the first time. Previously unknown tritium labeled N-phenyl quaternary derivatives of pyrazine and quinoxaline, which are potential radioactive biomarkers, have been obtained by nuclear-chemical method.
基金supported by the National Natural Science Foundation of China(22176138,22276129)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘The efficient separation of fission products,such as TcO_(4)^(-)and I^(-),holds strategic significance for the management of radioactive wastes and environmental protection.In this study,we propose an ultrafast strategy for scalable preparation of a highly quaternized organic network to facilitate efficient and synchronous separation of iodide and pertechnetate.The network can be prepared within a few minutes at room temperature,using polyethylenimine and 1,2,4,5-tetrakis(bromomethyl)benzene as building blocks.After chlorine replacement,the network,abundantly decorated with quaternary ammonium groups(Cl@QPN),exhibits an ultrahigh positive charge density of 7.6 mmol/g.This enables the rapid and efficient enrichment of target anions through strong electrostatic Coulomb interactions.As a result,Cl@QPN exhibits significantly higher adsorption rate constants of 0.830 g/(mg min)for ReO_(4)^(-)(a nonradioactive surrogate of TcO_(4)^(-))and 0.677 g/(mg min)for I-compared to other materials.Furthermore,it possesses high adsorption capacities,reaching 1,681 mg/g for ReO_(4)^(-)and 917.4 mg/g for I-.Cl@QPN also demonstrates good selectivity towards target ions and shows efficient adsorption for^(99)TcO_(4)^(-).Additionally,Cl@QPN exhibits high dynamic processing capacities,handling up to 3,100 and 7,400 kg of simulated streams per kilogram of material for I-and ReO_(4)^(-),respectively.
基金This work was supported by the National Natural Science Foundation of China （Nos. 20902104, 21072215 and 21172250）, Innovation Method Fund of China （No. 2010IM030900） and CAS （Nos. YZ200938, YG2010056）.
文摘Based on our previous report on N-alkylpyridinium isotope quaternization （NAPIQ） for the analysis of alcoholic and α,β-unsaturated ketone compounds, we have further applied NAPIQ method in the screening of hair lipids in drug abusers. Relative isotopic quantification was used for comparison of fatty alcohols between normal and drug abuse group, The NAPIQ strategy was proven to be a high-throughput method in the metabolic comparison studies of different group samples. The attached N-cationic pyridinium significantly improved the detection sensitivity for these fatty alcohols in matrix-assisted laser desorption/ionization Fourier transform ion cyclotron resonance mass spectrometric （MALDI-FTMS） analysis. The experimental results showed that the levels of fatty alcohols in the hair of heroin abuse group decreased significantly compared with the normal groups, which may be the results of the inducing of peroxidation enzyme. NAPIQ was proven to be an effective and alternative method in the research of fatty alcoholic metabolism for drug abuse monitoring.
基金This work was financially supported by this work was supported by State Key Laboratory of Pulp and Paper Engineering(No.2020ZR05)the National Natural Science Foundation of China(No.31622044)the project from and the Fundamental Research Funds for the Central Universities(No.2020ZYGXZR066).
文摘Cellulose nanofibers(CNF)are considered to be a potential substrate of energy material for energy storage devices due to the foldable,lightweight,recyclable and environmentally friendly feature.However,the energy materials tend to distribute unevenly or fall off from CNF easily,resulting in the decrease of the devices’overall performance.Here,for the first time,we used quaternized chitosan(QCS)as stabilizer and adhesive to in situ synthesize and deposite copper sulfide nanocrystals(CuS-NCs)on CNF and further obtained the conductive paper for flexible supercapacitors.In the presence of QCS,CuS-NCs deposited in situ on CNF can be capped and stabilized by the QCS molecular chains for uniform distribution,which is conducive to the capacitive behavior and electrochemical stability of composite paper.The result shows that the specific capacitance of the composite paper was as high as 314.3 F/g at a current density of 1 A/g,a high rate capacitance of 252.6 F/g was achieved even at a high current density of 10 A/g.It reveals that the composite paper exhibited better electrochemical performance than many other CuS-based electrode materials for supercapacitor.More importantly,the composite paper performed well in various folding state without changing much electrochemical performance.Therefore,this work provides a novel strategy to in situ fabricate paper-based electrode for nextgeneration flexible energy-storage system.
基金This work was supported by the Medical Science Advancement Program(Clinical Medicine)of Wuhan University(TFLC2018003)the Horizontal Research Program of Zhengzhou University(24110005)+1 种基金the Science and Technology Department of Hubei Province Key Project(2018ACA159)the Chinese Central Special Fund for Local Science and Technology Development of Hubei Province(2018ZYYD023).
文摘Innovative biomedical applications have high requirements for biomedical materials.Herein,a series of biocompatible,antibacterial and hemostatic sponges were successfully fabricated for the treatment of acute upper gastrointestinal bleeding(AUGB).Quaternized chitosan(QC)and soy protein isolate(SPI)were chemically cross-linked to obtain porous SPI/QC sponges(named SQS-n,with n¼30,40,50 or 60 corresponding to the weight percentage of the QC content).The chemical composition,physical properties and biological activity of SQS-n were investigated.SQS-n could support the adhesion and proliferation of L929 cells while triggering no obvious blood toxicity.Meanwhile,SQS-n exhibited good broad-spectrum antibacterial activity against both grampositive bacteria(Staphylococcus aureus)and gram-negative bacteria(Escherichia coli).The in vivo hemostatic effect of SQS-n was evaluated using three different bleeding models.The results revealed that SQS-50 performed best in reducing blood loss and hemostatic time.The overall hemostatic effect of SQS-50 was comparable to that of a commercial gelatin sponge.The enhanced antibacterial and hemostatic activities of SQS-n were mainly attributed to the QC component.In conclusion,this work developed a QC-functionalized hemostatic sponge that is highly desirable for innovative biomedical applications,such as AUGB.
