Hierarchical Reduced Graphene Oxide-MnO_(2)@Polypyrrole Coaxial Nanotube Composite Hydrogel as a Potential Adsorbent for Cr(Ⅵ)Removal

A hierarchical reduced graphene oxide-MnO_(2)@polypyrrole coaxial nanotube composite hydrogel was prepared via oxidative polymerization of pyrrole in the presence of MnO_(2)nanotubes,followed by the hydrothermal treatment of graphene oxide and MnO_(2)@polypyrrole coaxial nanotubes.The stable composite hydrogel with a hierarchical network was composed of one-dimensional MnO_(2)@polypyrrole coaxial nanotube and two-dimensional graphene nanosheet and characterized by scanning electron microscope,Fourier transform infrared spectroscopy,X-ray diffraction,Brunauer-Emmett-Teller surface,and X-ray photoelectron spectroscopy measurements.The composite hydrogel can be used as an efficient adsorbent for Cr(Ⅵ)removal due to the synergistic interaction between graphene and MnO_(2)@polypyrrole and the hierarchical structure of the hydrogel.Moreover,the composite hydrogel is easily separated because of its stable monolith,and it is reusable(76.8%of removal ability remaining after five adsorption-desorption cycles).The simple fabrication and cost-effective separation process together with the excellent absorption performance endow the composite hydrogel with great potential for practical wastewater treatment.

Application of Silica Aerogel Carrier via Supercritical Drying for Fragrance Controlled-release

Silica aerogel with different hydrophilicities were prepared from tetramethoxysilane,Methymethoxysilane,tetramethoxysilane-propyltrimethoxysilane,or tetramethoxysilane-phenyltrimethoxysilane mixtures via supercritical drying process(labelled as TMOS-AG Me-TMOS-AG,Pr-TMOS-AG,or Ph-TMOS-AG,respectively).Three fragrances,including geraniol,ethyl vanillin,and menthol,were loaded to TMOS-AG.The thermal analysis confirmed all loading fragrances are stable until over 200℃.And among all fragrances,geraniol presented the maximum loading contents(L_(m)).Concentration dependences indicated the geraniol was mono layer absorbed.Py-GC/MS of geraniol in TMOS-AG under both N_(2)and mimic air atmosphere(90%N_(2)and 10%O_(2))confirmed that loaded geraniol could be thermally controlled-released beginning at 200℃.As N_(2)absorption confirmed,even absorption/desorption equilibrium constant(k)was determined mainly by hydrophilicity of silica aerogels,and the maximum loading contents(L_(m))were influenced more by the pore size.Due to mono layered absorption,bigger pores usually give less specific areas and less absorbing sites for geraniol,and then present lower L_(m).

Silicone Chain Extender for Recycled Polyethylene-terephthalate with Higher Flexibility

To decrease the modulus and increase the mechanical properties of recycled PET by introducing the flexible segments, the recycled polyethylene-terephthalate(PET) was modified by the chain extender produced with 2, 4, 6, 8-tetramethyl-2, 4, 6, 8-tetra(2, 3-epoxypropoxy) propylcyclotetrasiloxane by the hydrosilylation reaction. Different percentages of chain extender were used in order to investigate the effect of chain extender content on the modulus of PET. The dynamic mechanical analysis was performed on PET samples, which showed that Tg of PET was firstly raised by the addition of chain extender and then decreased. Small amplitude shearing test performed on PET samples confirmed that the addition of the flexible segments could remarkably decrease the modulus of PET, which would be helpful for the extrusion process. The entanglements from branches were also influenced by the addition of extender.

Silicone Modified Polyesters Vulcanizable at Room Temperature for Anti-corrosion Coatings on Tinplate

Trimethoxysilyl Polyester(TMOS-PET)was prepared via hydrosilylation of trimethylsilane with acryl-terminated polyester.Copolymerization of TMOS-PET with trimethylmethoxysilane,tetramethoxysilane,and/or dimethyldimethoxysilane give silicone modified polyesters(Si-PET)containing=(SiO_(2))=,-(CH_(3)SiO_(3/2))=,and/or-((CH_(3))_(2)SiO)-units.Coatings from Si-PET were formed on tinplate surface via room temperature vulcanization with applicable curing time(the quickest tact free time and completely drying time are 2 h and 15 h,respectively).Mechanical properties,thermal stability,chemical resistance,and anti-corrosion of coatings were detected.Although the flexibility of the coatings were lowered by=(SiO_(2))=and-(CH_(3)SiO_(3/2))=units,adhesion and thermal stability of coatings were both improved.On the contrary,(CH_(3))_(2)SiOunits seem to improve the flexibility,while decrease the adhesive force for less crosslink points.Generally,the silicone modified polyesters act as an effective shielding for tinplate.According to electrochemical impedance spectroscopy(EIS),the electric resistance of coatings(Rc)were improved about 25 times and open circuit potential(OCP)increased about 0.10 V compared to the control.The chemical resistance and anti-corrosion of the coatings were decreased slightly after=(SiO_(2))=and-(CH_(3)SiO_(3/2))=units were added,but they could be greatly improved by-(CH_(3)SiO_(3/2))=units.Specially,after adding-(CH_(3)SiO_(3/2))=units,coatings give doubled Rc,and its OCP is about 0.20 V higher than the control.

Effect of Thermal Conductivity of Tube-Wall on Blow-Off Limit of a Micro-Jet Methane Diffusion Flame

The operating range of the flow rate or flow velocity for the micro-jet flame is quite wide,which can be used as the heat source.In order to optimize the micro-jet tube combustor in terms of the solid material,the present paper numerically investigates the impact of thermal conductivity(λs)on the operating limit of micro-jet flame.Unexpectedly,the non-monotonic blow-off limits with the increase ofλs is found,and the corresponding generation mechanisms are analyzed in terms of the thermal coupling effect,flow field,and strain effect.At first,the lower preheating temperature of the fuel and larger heat loss amount to the environment lead to a larger blow-off limit at a largerλs.After that,the smaller local flow velocity in the vicinity of flame root and smaller strain effect slightly increase the blow-off limit with the continuously increasingλs.Therefore,it is deduced that the applied performance of micro-jet combustor with a smaller thermal conductivity is better in terms of the blow-off limit.

Controllable Synthesis of Carboxymethyl Cellulose and Its Application in Tobacco Sheets

Carboxymethyl cellulose(CMC)with different degree of substitution(DS)was prepared by controlling feed ratio and times of alkalization and etherification.CMC with different molecular weight was prepared by degradation of hydrochloric acid solution.Orthogonal experiments were designed to study the effects of addition amount,molecular weight and DS of CMC on the tensile strength of tobacco sheets.The effects of CMC on the thermal properties and aerosol release of tobacco sheets were also studied.The results showed that the addition amount and the molecular weight of CMC had obvious effect on the tensile strength of tobacco sheets.The DS of CMC had no significant effect on the tensile strength of tobacco sheets.The addition of CMC improved the thermal stability of tobacco sheets to a certain extent,and had certain influence on the content of nicotine in aerosol.

Preparation and Evaluation of MPEG-PCL Polymeric Nanoparticles Against Gastric Cancer

This paper provides a new treatment for gastric cancer with a new OMT delivery system.We synthesized MPEG-PCL,an amphiphilic polymer,to construct a nanoparticle encapsulated OMT by pH gradient method,and then examined the nanodrug’s therapeutic efficacy.An integral analytical method was used to characterize the structure of MPEG-PCL.The single factor method and orthogonal test were utilized to investigate the optimum preparation process.The morphology and average size of the OMT-NPs were analyzed by transmission electron microscopy and Zetasizer.CCK-8 assay and confocal fluorescent microscope were used to study the inhibitory effect on SGC-7901 gastric cancer cells.The average size of nanoparticles was 95.86±1.54 nm.The maximum encapsulation efficiency of OMT was 46.84±4.37%,while the drug loading content was 8.89±1.09%.The cumulative release of nanoparticles was 73.07±1.5%,inspected through dynamic dialysis in vitro.Compared with free OMT,OMT-NPs showed enhanced cytotoxic effects in SGC-7901 cells.The nanoparticles could efficiently deliver the OMT into the cancer cells and release it.The OMT delivery system prepared in this paper provides a potential platform for the treatment of gastric cancer..

A non-monotonic blow-off limit of micro-jet methane diffusion flame at different tube-wall thicknesses

In order to provide guideline for choosing a suitable tube-wall thickness(d)for the micro-jet methane diffusion flame,the effect of tube-wall thickness on the blow-off limit is investigated via numerical simulation in the present work.The results show that the blow-off limit of micro-jet methane diffusion flame firstly increases and then decreases with the increase of tube-wall thickness.Subsequently,the underlying mechanisms responsible for the above non-monotonic blow-off limit are discussed in terms of the flow filed,strain effect and conjugate heat exchange.The analysis indicates that the flow field is insignificant for the non-monotonic blow-off limit.A smaller strain effect can induce the increase of the blow-off limit fromd=0.1 to 0.2 mm,and a worse heat recirculation effect can induce the decrease of the blow-off limit fromd=0.2 to 0.4 mm.The non-monotonic blow-off limit is mainly determined by the heat loss of flame to the tube-wall and the performance of tube-wall on preheating unburned fuel.The smallest heat loss of flame to the tube-wall and the best performance of tube-wall on preheating unburned fuel result in the largest blow-off limit atd=0.2 mm.Therefore,a moderate tube-wall thickness is more suitable to manufacture the micro-jet burner.

Deposition of IrO_(2) on Nb-doped SnO_(2) as Electrocatalysts for Oxygen Evolution Reactions

We reported sol-gel-derived Nb-doped SnO_(2) which is an effective catalyst carrier for deposition of IrO_(2),and the electrocatalytic activity of the synthesized catalysts for OER was investigated.It is found that the doping of Nb can refine the SnO_(2) crystal grains and improve the electrical conductivity of SnO_(2).When the doping amount of Nb is 7%,the electrical conductivity of Nb-SnO_(2) reaches a maximum value of 3.54 S/cm.With the increase in the loading amount of IrO_(2),the electrocatalytic activity towards OER of the thus-synthesized catalysts is improved,reaching a comparable OER activity with pristine IrO_(2) with the loading content of about 44wt%.

Surface active functional groups enhanced PET non-woven fabric for the filtering of harmful substances in smoke

Harmful components in cigarette smoke,such as nicotine,tar,and organic particulate matter,are the primary culprits behind lung diseases.While conventional filter materials based on cellulose,carbon,and molecular sieves exhibit commendable filtration capabilities,their high cost restricts their widespread applications.Based on this,the authors aim to prepare PET-based filter materials with good adsorption properties through a simple surface functionalisation strategy.The adsorption performance of the PET-based non-woven fabric was enhanced by the introduction of sodium alginate(SA).The gas adsorption experiments results reveal that SA-modified PET(SA-PET)exhibits significantly improved filtration efficiency for nicotine,tar,and total particulate matter—increasing by 27.1%,26.2%,and 21.3%,respectively.Moreover,SA-PET exhibits more odour control ability than traditional activated carbon-based filter materials.These results prove that surface-functionalised SA-PET has better filtration performance for harmful substances in smoke and provides a new strategy for the design of high-performance filtration materials.