Amino-functionalized UiO-66-doped mixed matrix membranes with high permeation performance and fouling resistance

For the reduction of bovine serum proteins from wastewater,a novel mixed matrix membrane was prepared by functionalizing the substrate material polyaryletherketone(PAEK),followed by carboxyl groups(C-SPAEKS),and then adding amino-functionalized UiO-66-NH_(2)(Am-UiO-66-NH_(2)).Aminofunctionalization of UiO-66 was accomplished by melamine,followed by an amidation reaction to immobilize Am-UiO-66-NH_(2),which was immobilized on the surface of the membrane as well as in the pore channels,which enhanced the hydrophilicity of the membrane surface while increasing the negative potential of the membrane surface.This nanoparticle-loaded ultrafiltration membrane has good permeation performance,with a pure water flux of up to 482.3 L·m^(-2)·h^(-1) for C-SPAEKS/AmUiO-66-NH_(2) and a retention rate of up to 98.7%for bovine serum albumin(BSA)-contaminated solutions.Meanwhile,after several hydrophilic modifications,the flux recovery of BSA contaminants by this series of membranes increased from 56.2%to 80.55%of pure membranes.The results of ultra-filtration flux time tests performed at room temperature showed that the series of ultrafiltration membranes remained relatively stable over a test time of 300 min.Thus,the newly developed mixed matrix membrane showed potential for high efficiency and stability in wastewater treatment containing bovine serum proteins.

Can amino-functionalized carbon nanotubes carry functional nerve growth factor?

Carbon nanotubes can carry protein into cells to induce biological effects. Amino-functionalized carbon nanotubes are soluble and biocompatible, have high reactivity and low toxicity, and can help promote nerve cell growth. In this study, amino-functionalized ethylenediamine-treated multi-walled carbon nanotubes were used to prepare carbon nanotubes-nerve growth factor complexes by non-covalent grafting. The physicochemical properties, cytotoxicity to PC12 and chick embryo dorsal root ganglion, and biological activity of the carbon nanotubes-nerve growth factor complexes were investigated. The results showed that amino functionalization improved carbon nanotubes-nerve growth factor complex dispersibility, reduced their toxicity to PC12 cells, and promoted PC 12 cell differentiation and chick embryo dorsal root ganglion.

Recent Advances in Swine Amino Acid Nutrition

Recent advances in swine protein nutrition are characterized by the development of functional a- mino acids （AA） in regulating fetal and postnatal survival, growth and development. These AA include arginine, glutamine, glutamate, proline, leucine, cyste- ine and tryptophan. Due to limited knowledge on AA nutrition, pork producers have traditionally paid little attention to supplementing the arginine family of AA to swine diets. Results of recent studies indicate that functional AA serve important regulatory functions in nutrient metabolism, protein turnover, and immune function, therefore enhancing efficiency of feed utili- zation by pigs. The underlying mechanisms include activation of nitric oxide, mammalian target of rapam- ycin, gaseous signaling, and AMP-activated protein ki- nase pathways, as well as anti-oxidative function. Di- etary supplementation with arginine, glutamine, pro- line or leucine to weanling piglets enhances theirgrowth performance. Arginine or glutamine is also ef- fective in increasing milk production by lactating sows. Furthermore, supplementing arginine to the diet of pregnant gilts between days 30 and 114 of gestation increases the number of live-born piglets and litter birth-weight. Availability of feed-grade functional AA holds great promise for improving animal health and nutrient utilization in pig production worldwide. Addi- tionally, feedstuffs of animal origin [ e. g. , blood meal （ ring dried ）, feather meal （ hydrolyzed ）, meat and bone meal, porcine protein meal, and poultry by-prod- uct meal （both feed- and petfood-grades） ] are excel- lent and cost-effective sources of both essential and functional AA for formulating balanced swine diets. New knowledge on AA nutrition provides a much needed scientific basis for revising the next edition of swine nutrient requirements.

Highly selective hydrogenation of furfural to tetrahydrofurfuryl alcohol over MIL-101(Cr)-NH_2 supported Pd catalyst at low temperature

An efficient heterogeneous catalyst,Pd@MIL‐101(Cr)‐NH2,is prepared through a direct pathway of anionic exchange followed by hydrogen reduction with amino‐containing MIL‐101as the host matrix.The composite is thermally stable up to350°C and the Pd nanoparticles uniformly disperse on the matal organic framework(MOF)support,which are attributed to the presence of the amino groups in the frameworks of MIL‐101(Cr)‐NH2.The selective hydrogenation of biomass‐based furfural to tetrahydrofurfuryl alcohol is investigated by using this multifunctional catalyst Pd@MIL‐101(Cr)‐NH2in water media.A complete hydrogenation of furfural is achieved at a low temperature of40°C with the selectivity of tetrahydrofurfuryl alcohol close to100%.The amine‐functionalized MOF improves the hydrogen bonding interactions between the intermediate furfuryl alcohol and the support,which is conducive for the further hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol in good coordination with the metal sites.

Film Morphology,Emulsification of Dodecyl/Carboxyl Modified Polysiloxane and Its Application Performance on Cotton Fabrics

The film morphology of dodecyl/carboxyl modified polysiloxane(RCAS) on cotton fabric or the silicon wafer was investigated and characterized by field emission scanning electron microscopy(FESEM),atomic force microscope(AFM),and Fourier transform infrared spectrometer(FTIR).Experimental results indicate that RCAS is a good film forming material on different substrates.Relatively smooth film was formed on cotton fabric surface,on which the grooves disappeared.In addition,RCAS formed a micromorphology inhomogeneous and unsmooth film on the silicon wafer.Many high or low bright peaks distributed randomly on the film surface,especially as the field was 2μm×2 μm and the date scale was 5 nm in AFM observation.Then RCAS was emulsified with nonionic surfactant alkyl polyoxyethylene ether in order to achieve a transparent organosilicon emulsion-RCAS emulsion(RCSE),which possessed good stability.The properties of RCSE and its application performance on cotton fabrics were investigated and characterized by transmission electron microscope(TEM),particle size analysis,and voltage test instrument.The results show that the average particle size of RCAS emulsion is 28.32 nm,while the ζ voltage is-37.88 mV.Compared with untreatd cotton fabric,the softness of treated fabric can be improved with RCSE to a certain extent.At the same time,the fabric treated with RCSE acquires unique fluffy and soft handle.

Absorption and Fluorescence Properties of Oxidized and N-doped Graphene Quantum Dots:A Time-dependent DFT Study

Absorption and emission properties of oxidized graphene quantum dots （GQDs） and amino functionalized GQDs （NG） were explored by B3LYP method combined with 6-31G （d） basis set. The oxygen- and nitrogen-containing groups can tune the intensity as well as the wavelength of absorption and emission. The groups such as hydroxyl, carboxyl, amino, amide, and pyridine-like N can appropriately lengthen the absorption and emission wavelength of GQDs. However, the carbonyl group, graphitic-like N, and pyrrolic-like N obviously decrease the oscillator strength and lengthen the emission wavelength of GQDs out of the visible region. The lowest excited state S_1 of NG has the strongest emission in investigated complexes, which indicates that it is an excellent luminous material. The theoretical investigations verify that the oxygen- and nitrogen-related groups can tune the luminescence of GQDs. The fluorescence quenching of GQDs reduced by ammonia mainly depends on the graphitic-like and pyrrolic-like N.

Synthesis of unnatural amino acids through palladium-catalyzed C(sp^3)-H functionalization

Unnatural a-amino acids have been extensively used in the modern drug discovery and protein engineering studies. They have also found applications in the development of chiral molecular catalysts and the total synthesis of diverse natural products. Accordingly the development of cost-effective approaches for the preparation of unnatural a-amino acids has received increasing attentions. Among all the available methods for this purpose, direct C–H functionalization of simple amino acids represents one of the most attractive approaches because it exhibits good atom-economy and step-efficiency. In particular, selective functionalization of either the primary or secondary C（sp^3）–H bonds in the amino acids has been explored to make versatile C–C, C–N, C–O, C–B and C–F bonds to modify the side chain of amino acids and even peptides. The present review surveys the recent advances of synthesis of chiral unnatural a-amino acids and peptides through palladium-catalyzed functionalization of un-activated C（sp^3）–H bonds.

Silage Feeding with Water Hyacinth in the Tropics: A Research Note

Water hyacinth has ecological significance in addition to its agricultural and energy uses. Lower quality silage is defined in this paper as requiring nitrogen supplementation and treatment to improve nutritive value (NV). Ensilage of water hyacinth as a test case centers largely around the process to optimize protein nitrogen retention in silage-based regimens. A previous hypothesis proposed earlier by the author of that of functional amino acid ratios [tyrosine (TYR): large neutral amino acids (LNAA), tyrosine (TYR): phenylalanine (PHE)] were subsequently found to be counter to what the given schemata predicts. And subsequently with another study there was no corroborative evidence for it to support the espoused hypothesis using the same schemata. The role of N status is still the most viable option among factors from studies continuing how amino acids like histidine (HIS) and arginine (ARG) and their growth-related endocrine functions play a role. There are other schemas illustrating non-homeostatic type regulation with protein intake. To focus on molecular-level mechanisms to ruminal protein digestion it is becoming clear what factors in feed and microbial cell fermentation contribute to optimizing microbial cell protein (MCP) synthesis from ATP with organic matter (OM) digestibility and preformed amino acids (PFAA) from peptides and free amino acids in addition to non-protein nitrogen (NPN), the former more efficiently assimilated in MCP than NPN in the rumen. Accordingly, it has been recommended that soluble proteins fed to dairy cows not exceed microbial requirements along with high dietary escape protein fed with a sufficient amino acid profile to meet dairy production.

Amino-functionalized Ti_(3)C_(2)T_(x) with anti-corrosive/wear function for waterborne epoxy coating

Two-dimensional Ti_(3)C_(2)T_(x) flakes have great application potential in various areas due to their optical,electronic,electrochemical and mechanical properties,but their anti-corrosion and wear-resistance performance were not well understood.The difficulties in achieving good dispersity and interface interaction of inorganic additives in organic coatings hinder the incorporation of Ti_(3)C_(2)T_(x) into the epoxy coating.Here,few-layered Ti_(3)C_(2)T_(x) sheets with amino-functionalization were prepared,and as reinforced-additives were added into the waterborne epoxy coating.Anti-corrosion and tribological properties of as-prepared composite coatings were investigated in detail.The results reveal that the composite coating with 0.5 wt.%amino-functionalized Ti_(3)C_(2)T_(x) sheets shows excellent corrosion protection(the lowest frequency impedance was 3.12×10^(9) cm^(2))and wear resistance(wear rate was reduced by 72.74%).The greatly improving performance of composite coatings mainly depends on:(a)good dispersity and compatibility of amino-functionalized Ti_(3)C_(2)T_(x) in organic matrix,(b)high adhesion strength between coating and metal substrate and(c)the intrinsic properties of Ti3C2Tx sheets.The work provides a good path for applications of MXene as multifunctional additives.

A facile and controllable one-pot synthesis approach to amino-functionalized hollow silica nanoparticles with accessible ordered mesoporous shells

The development of a practical synthetic method to functionalize hollow mesoporous silica with organic groups is of current intere st for selective adsorption and ene rgy storage applications.Herein,a facile and controllable one-pot approach for the synthesis of monodisperse amino-functionalized hollow mesoporous silica nanoparticles is presented.A novel solid-to-hollow structural transformation procedure of the silica nanoparticles is presented.The structural transformation is easily designed,as obse rved through transmission electro n microscopy,by tailo ring the HCl and N-lauroylsarcosine sodium molar ratio and the water content in the sol-gel.Ordered and radially oriented in situ aminofunctionalized mesochannels were successfully introduced into the shells of the hollow silica nanoparticles.A formation mechanism for the hollow mesoporous silica materials is discussed.

Magnetic KIT-6 nano-composite and its amino derivatives as convenient adsorbent for U(Ⅵ)sequestration

Although mesoporous silica with magnetically hybridized two-dimensional channel structures has been well studied in recent years,it remains a challenge to fabricate the counterpart with macroporous three-dimensional cubic structures since the highly acidic preparation conditions lead to dissolution of magnetic particles.Herein,we successfully prepared magnetic KIT-6 nano-composite and its amino derivatives by bearing acid-resistant iron oxide.The prepared materials exhibited excellent properties for U(VI)ions removal from aqueous solutions under various conditions.The experimental data show that the U(VI)adsorption features fast adsorption kinetics,high adsorption capacity and ideal selectivity toward U(VI).The adsorption process is of spontaneous and endothermic nature and ionic strength independence,and the adsorbents can be easily regenerated by acid treatment.Compared to pristine KIT-6,the introduction of magnetism does not reduce the efficiency of the material to remove U(VI)while exerting its role as a recovery adsorbent.The findings of this work further demonstrate the potential broad application prospects of magnetic hybrid mesoporous silica in radionuclide chelation.

Molecular modulating of cobalt phthalocyanines on aminofunctionalized carbon nanotubes for enhanced electrocatalytic CO_(2)conversion

Metal porphyrins and metal phthalocyanines(Pc)constitute a promising class of metal molecular catalysts(MMCs)for efficient CO_(2)-to-CO electrocatalytic conversion due to their well-defined molecular structures.How to adjust the local coordination and electronic environment of the metal center and enhance the molecular-level dispersion of the active components remains as great challenges for further improving the performance.Herein,a cobalt(II)Pc(CoPc)-COOH/carbon nanotube(CNT)-NH_(2)hybrid catalyst was rationally designed by clicking the CoPc-COOH molecules onto the surface of CNT-NH_(2)through amidation reaction.This novel hybrid catalyst exhibited the enhanced current density of 22.4 mA/cm2 and CO selectivity of 91%at−0.88 V vs.reversible hydrogen electrode(RHE)in the CO_(2)electroreduction,as compared with CoPc-COOH/CNT and CoPc/CNT samples.The superior activity was ascribed to the charge transfer induced by introduction of-COOH and-NH_(2)functional groups to CoPc and CNT,respectively,facilitating the active centers of CoI being generated at lower potentials,and leading to the highest turnover frequency(TOF)being obtained over the CoPc-COOH/CNT-NH_(2)hybrid catalyst.The inherent directivity and saturability of covalent bonds formed via the amidation reaction ensure not only a higher density of Co active centers,but also an improved stability for CO_(2)reduction reaction(CO_(2)RR).The present study represents an effective strategy for improving MMCs performance by molecular modulating of metal phthalocyanines on functionalized carbon substrates directed by click confinement chemistry.

SYNTHESIS AND CHARACTERIZATION OF AMINO FUNCTIONALIZED LADDER-LIKE POLYSILSESQUIOXANES AND THEIR HYBRID FILMS WITH POLYIMIDE

Ladder-like polysilsesquioxanes （LPSQs） with different amino contents have been synthesized by controlling of the dosage of Pd/C catalyst. The concentration and activity of amino groups were investigated by Fourier transform infrared spectroscopy. Polyimide （PI）/LPSQ hybrid films have been prepared by incorporating of the obtained LPSQs with different amino contents into PI matrix, respectively. The interfacial interactions between PI matrix and LPSQ were studied with scanning electron microscopy and X-ray photoelectron spectroscopy, meanwhile the thermal and mechanical properties of the hybrid films were studied using dynamic mechanical analysis and tensile tests. The results indicate that the functionality of LPSQ has great effects on the interfacial interactions and the properties of hybrid films. With the increase of amino content, both the interracial interactions and the cross-linking density of hybrids enhanced, which results in the decline of surface silicon concentration, increase of Young＇s modulus and drop of elongation at break. Excessive amino content makes the hybrid films brittle and leads to incomplete imidization.

Crosslinking acrylamide with EDTA-intercalated layered double hydroxide for enhanced recovery of Cr(Ⅵ)and Congo red:Adsorptive and mechanistic study

We prepared ethylenediaminetetraacetic acid(EDTA)-intercalated MgAl-layered double hydroxide(LDH-EDTA),then grafted acrylamide(AM)to the LDH-EDTA by a cross-linking method to yield a LDH-EDTA-AM composite;we then evaluated its adsorptive ability for Congo red(CR)and hexavalent chromium(Cr(Ⅵ))in single and binaiy adsorption systems.The adsorption process on LDH-EDTA-AM for CR and Cr(Ⅵ)achieved equilibrium quickly,and the removal efficiencies were minimally affected by initial pH.The maximum uptake quantities of CR and Cr(Ⅵ)on LDH-EDTAAM were 632.9 and 48.47 mg/g,respectively.In mixed systems,chromate removal was stimulated by the presence of CR,while the adsorption efficiency of C R was almost not influenced by coexisting Cr(Ⅵ).The mechanisms involved electrostatic attraction,surface complexation,and anion exchange for the adsorption of both hazardous pollutants.In the Cr(Ⅵ)adsorption process,reduction also took place.The removal efficiencies in real contaminated water were all higher than those in the laboratory solutions.

Construction of mesoporous ceria-supported gold catalysts with rich oxygen vacancies for efficient CO oxidation

Bearing unique redox nature and high oxygen storage capacity,ceria(CeO_(2))has always been a promising CO oxidation catalyst support for gold(Au)catalysts and the like.Herein,a series of Au-CeO_(2)-P(P stands for pH value)samples was prepared by a co-precipitation method with the assistance of an alkaline environment and amino groups functionalized ordered mesoporous polymer(OMP-NH_(2)).Afterward,all samples described above were characterized that the Au-CeO_(2)-P catalysts are made of Au-Ce-O solid solution and Au nanoparticles(NPs)supported on CeO_(2).It turns out that OMP-NH_(2) is not just a simple sacrificial template for mesoporous structure,but also plays an important role as an amino source,explaining the presence of rich oxygen vacancies.Due to the concentration of oxygen vacancies in Au-Ce-O solid solution is the key factor for the oxygen mobility of CO oxidation,the catalytic results also demonstrate that the catalytic activity of Au-CeO_(2)-P catalysts is related to the concentration of their oxygen vacancies.Moreover,Au-CeO_(2)-9.6 with a highest concentration of oxygen vacancies(as high as 13.98%)in Au-CeO_(2)-P catalysts exhibits the best catalytic activity(complete conversion at 10℃).