Microbial Community Dynamics During Biogas Slurry and Cow Manure Compost

This study evaluated the microbial community dynamics and maturation time of two compost systems： biogas slurry compost and cow manure compost, with the aim of evaluating the potential utility of a biogas slurry compost system. Denaturing gradient gel electrophoresis （DGGE）, gene clone library, temperature, C/N ratio, and the germination index were employed for the investigation, cow manure compost was used as the control. Results showed that the basic strip and dominant strips of the DGGE bands for biogas slurry compost were similar to those of cow manure compost, but the brightness of the respective strips for each system were different. Shannon-Weaver indices of the two compost systems differed, possessing only 22% similarity in the primary and maturity stages of the compost process. Using bacterial 16S rRNA gene clone library analysis, 88 bacterial clones were detected. Further, 18 and 13 operational taxonomic units （OTUs） were present in biogas slurry and cow manure compost, respectively. The 18 OTUs of the biogas slurry compost belonged to nine bacterial genera, of which the dominant strains were Bacillus sp. and Carnobacterium sp.; the 13 OTUs of the cow manure compost belonged to eight bacterial genera, of which the dominant strains were Psychrobacter sp., Pseudomonas sp., and Clostridium sp. Results demonstrated that the duration of the thermophilic phase （more than 50°C） for biogas slurry compost was 8 d less than the according duration for cow manure compost, and the maturation times for biogas slurry and cow manure compost were 45 and 60 d, respectively. It is an effective biogas slurry assimilate technology by application of biogas slurry as nitrogen additives in the manufacture of organic fertilizer.

Electronic modulation and interface engineering of electrospun nanomaterials‐based electrocatalysts toward water splitting

Nowdays,electrocatalytic water splitting has been regarded as one of the most efficient means to approach the urgent energy crisis and environmental issues.However,to speed up the electrocatalytic conversion efficiency of their half reactions including hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),electrocatalysts are usually essential to reduce their kinetic energy barriers.Electrospun nanomaterials possess a unique one‐dimensional structure for outstanding electron and mass transportation,large specific surface area,and the possibilities of flexibility with the porous feature,which are good candidates as efficient electrocatalysts for water splitting.In this review,we focus on the recent research progress on the electrospun nanomaterials‐based electrocatalysts for HER,OER,and overall water splitting reaction.Specifically,the insights of the influence of the electronic modulation and interface engineering of these electrocatalysts on their electrocatalytic activities will be deeply discussed and highlighted.Furthermore,the challenges and development opportunities of the electrospun nanomaterials‐based electrocatalysts for water splitting are featured.Based on the achievements of the significantly enhanced performance from the electronic modulation and interface engineering of these electrocatalysts,full utilization of these materials for practical energy conversion is anticipated.

Decoration of Electrospun Nanofibers with Magnetic Nanoparticles via Electrospinning and Sol-gel Process

Polyacrylonitrile（PAN）/Fe3O4 composite nanofibers were successfully obtained through electrospinning and sol-gel technology. The resulting magnetic Fe3O4 nanoparticles were homogeneously distributed on the surface of PAN nanofibers and the diameters of polyacrylonitrile nanofibers and nanoparticles were easily controlled, respectively. The distribution of Fe3O4 nanoparticles inside the nanofibrous composite was investigated by field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction reveals the presence of Fe3O4 nanoparticles in the composite nanofiber. The resulting sample shows a super paramagnetic behavior.

Preparation and characterization of porous TiO_2/ZnO composite nanofibers via electrospinning

Porous TiO2/ZnO composite nanofibers have been successfully prepared by electrospinning technique for the first time.It was generated by calcining TiO2/ZnCl2/PVP[PVP：polyvinyl pyrrolidone）]nanofibers,which were electrospun from a mixture solution of TiO2,ZnCl2 and PVP.Transmission electron microscopy（TEM） and X-ray diffraction（XRD） analyses were used to identify the morphology of the TiO2/ZnO nanofibers and a formation of inorganic TiO2/ZnO fibers.The porous structure of the TiO2/ZnO fibers was characterized by N2 adsoption/desorption isotherm.Surface photovoltage spectroscopy（SPS） and photocatalytic activity measurements revealed advance properties of the porous TiO2/ZnO composite nanofibers and the results were compared with pure TiO2 nanofibers,pure ZnO nanofibers and TiO2/ZnO nanoparticles.

Allyl-containing Poly(aryl ether sulfone): Synthesis and Crosslinking

A novel type of crosslinkable poly（aryl ether sulfone）（PAES） bearing an allyl pendant（PES-OAllyl） was synthesized by a grafting reaction of hydrophenyl-containing PAES（PES-OH） and allyl bromide. PES-OH was prepared by a demethylation reaction of a methoxyphenylated PAES（PES-OCH3） in the presence of pyridine/hydrochlo- ride. The PES-OCH3 was synthesized by an aromatic nucleophilic substitution of bis（4-chlorophenyl）sulfone and （p-methoxy）phenylhydroquinone. Both DSC and solubility investigation were used to study the crosslinking behavior of PES-OAllyl. After heat treatment, the glass transition temperature（Tg） value of PES-OAllyl sharply increased from 165 ℃ to 227 ℃. Meanwhile, PES-OAllyl changed from a soluble polymer to an insoluble thermoset. In addition, TGA（thermogravimetric analysis） result suggests that the thermal stability of the crosslinked product was improved. All the data prove that the crosslinked PES-OAllyl could be a potential solvent-resistance high-performance material.

Influence of Mixing Conditions on Morphologies and Properties of MMT/Epoxy Resin Composite Materials

Montmorillonite（MMT） was directly modified with hexadecyl trimethyl ammonium bromide. The interlayer spacing of the organophilic montmorillonite（organo-MMT） corresponding to the d（001） plane peak was 2.21 nm The influences of the content of organo-MMT and mixing conditions including mixing temperature and mixing time on the intercalation and exfoliation structures of MMT/epoxy resin composites were investigated by wide X-ray diffraction（WXRD）. The X-ray patterns reveal that organo-MMT was intercalated by the epoxy resin during mixing process. Only under certain mixing conditions, could the exfoliation nanocomposites be formed. The mechanical and thermal properties of the composites were measured. The results indicate that the composites have better mechanical properties and higher Tg than those of the pristine epoxy resin.

Evolution of Morphology and Properties of Sulfonated Poly(ether ether ketone ketone) Membranes Fabricated via Electrospinning

Sulfonated poly（ether ether ketone kctone）（SPEEKK） membranes with different degrees of sulfonation（DS） were successfully prepared via electrospinning method. The morphology of the resulted membranes varies from nanospheres to nanofibers with increasing the concentration of SPEEKK. The conductivities of the membranes prepared under the same condition increase with the DS increasing. The spherical morphological membranes with a DS of 1.2 show the highest proton conductivity, 0.55 S/cm, which is much higher than those of the membranes prepared via normal solution evaporation method. The results show that electrospinning is an efficient method to prepare high performance SPEEKK membranes with different morphologies.

Synthesis and Properties of Poly(aryl ether ketone) Copolymers Containing 2,7-Naphthalene Moieties

Poly（ aryl ether ketone） copolymers containing 2,7-naphthylene and hydroquinone（HQ） moieties with various compositions were prepared by the reaction of 4,4＇-difluorobenzophenone（DFB） 2,7-naphthylene and hydroquinone in the presence of sodium carbonate and potassium carbonate （ 19： 1, mass ratio） in diphenyl sulfone （DPS）. The thermal analysis results of the copolymers show that the glass transition temperatures（Tgs） increase, while the melting temperatures（Tra） and tile 5.0% weight loss temperatures （ Td ） decrease with the increase of the 2,7-naphthalene moieties. For the copolymers synthesized at a molar fraction of 2,7-naphthalene in the difluoro monomers being over 0.30, no peaks corresponding to the cold crystallization temperature and the melting temperature could be detected, indicating that these copolymers are almost amorphous. The crystal structures of the copolymers with a molar fraction of 2,7-naphthalene being less than 0. 30 are rhombic.

Preparation of 5-Fluorouracil Loaded Polylactide-co-glycolide-co-methoxy Poly(ethylene glycol) (PLGA-mPEG) Nanoparticles via High Speed Shearing

5-Fluorouracil（5-FU） loaded nanoparticles（NPs） were prepared by a high speed shearing double emulsion method with polylactide-co-glycolide-co-methoxy poly（ethylene glycol）（PLGA-mPEG） as loading material. The prepared NPs possess a negative zeta potential and their loading efficiency is about 15%（mass fraction）. The result of in vitro release shows that the release behavior of 5-FU from NPs is coincident with Zero-level release from the second day.

Synthesis and characterization functionalized poly(ether ether ketone)s with carboxylic groups

A novel type of aromatic poly（ ether ether ketone） s with carboxyl groups were prepared by polycondensation of 4,4-bis（4-hydroxyphenyl）pentanoic acid with difluoro-monomers. Their mo- lecular structures were determined by ^1H-NMR and IR, respectively. Their molecular weights were measured by gel permeation chromatography （ GPC ）, which showed that all the polymers had high molecule weights （ 〉 42 000）. Due to the long side chains of polymers, all the polymers had good solubility （soluble in NMP, DMAc, THF, etc. ）. The differential scanning calorimeter （DSC） detected their excellent glass transition temperatures （ Tg ） up to 195 ℃. The Tg increased with the content of carboxylic units in the polymer chains, because the interactions of H bonds increased with increasing content of carboxylic. The polymers could form transparent and flexible films, which make them a candidate for membrane materials.

Study on New Pretreatment Combining Dilute Acid Treatment and Organic Solvent Water / Ethanol for Biorefinery： Application to Switch Grass

Switch grass was developed as a pioneer energy crop in USA with great industrial prospect. It contains about 60% sugars and 18% lignin. The purpose of this research is to find pretreatment process to fractionate cellulose, hemicellulose and lignin from switch grass to obtain much more useful chemicals and enhance the residue solid to be hydrolyzed by enzymes. The six different pretreatment methods were studied, such as hot water pretreatment （HWP） alone, dilute acid pretreatment （DAP）, ammonia pretreatment （AP）, lime pretreatment （LP）, organosolv water / ehanol pretreatment （OWEP）, and organosolv water / acetone pretreatment （OWAP）. It was the best method combining DAP with OWEP because the hemicellulose sugars were recovered in the first residual liquid while a varied amount of cellulose was retained in the residual solid and the lignin fraction was obtained by simply adjusting the pH from the second liquid. The result shows the optimal two-stage process consisted of the first stage DAP at 428 K for 7 min with 0.8% sulfuric acid, resulting in 79.82% glucose recovery yield and 98.74% xylose removal and the second stage OWEP at 468K for 20 min in 45% （v / v） ethanol with 0.4% NaOH, resulting in 62% total glucose yield 99% xylose and 80% lignin removal. After enzymatic hydrolysis, the glucose yield was up to 92.6%, compared with 16% yield from untreated switch grass. Scanning electron microscopy （SEM） highlighted the differences in switch grass structure from the various pretreatment methods during biomass fractionation.

Determination of hydroxyl radical in Fenton system

Under visible light illumination, 2,3-diaminophenazine （DAPN） was generated from the oxidation of o-phenylenediamine （OPDA） in Fe^3＋/H2O2 solution. Hydroxyl radical （＊OH） produced in this system was determined by directly measuring the concentration of DAPN. In comparison with the traditional methods, the determination is more accurate and simple.

Influence of Backbone Structure on Properties of Directly Polymerized Phenoxy Resins from Epichlorohydrin and Various Aromatic Dihydric Phenols Monomers

A series of phenoxy resins was directly prepared through the polymerization of each of the various aromatic dihydric phenols and epichlorohydrin.FTIR and 1H NMR spectra were recorded to characterize the structures of the re-sins.The GPC curves were used to determine the molecular weight distribution.In addition,the thermal properties of the resins were studied with differential scanning calorimetry（DSC）and thermal gravimetric analysis（TGA）.The thermal stabilities of the polymers increased with the content of the benzene ring,pendant group increasing or biphenyl groups emerging.The adhesive properties of the polymers were evaluated in terms of the lap shear strength with Fe-Fe adherends.The fracture mechanisms were determined by SEM observation and it was found that there was an important participation of cohesive fracture mechanisms.Also,it has been demonstrated that the extension of these micro-cohesive mechanisms is directly correlated with the adhesive strength.According to these results,the phenoxy resin containing biphenyl groups presented a higher adhesive strength and could improve the adhesive property of the epoxy/phenoxy system to a certain extent.

Characterization of the effective cellulose degrading strain CTL-6

An efficient cellulose degrading bacteria exists in the thermophilic wheat straw-degrading community, WDC2. However, this strain cannot be isolated and cultured using conventional separation techniques under strict anaerobic conditions. We successfully isolated a strain of effective cellulose degrading bacteria CTL-6 using a wash, heat shock, and solid-liquid alternating process. Analysis of its properties revealed that, although the community containing the strain CTL-6 grew under aerobic conditions, the purified strain CTL-6 only grew under anaerobic culture conditions. The strain CTL-6 had a striking capability of degrading cellulose （80.9% weight loss after 9 days of culture）. The highest efficiency value of the endocellulase （CMCase activity） was 0.404 μmol/（min·mL）, cellulose degradation efficiency by CTL-6 was remarkably high at 50–65°C with the highest degradation efficiency observed at 60°C. The 16S rRNA gene sequence analysis indicated that the closest relative to strain CTL-6 belonged to the genus Clostridium thermocellum. Strain CTL-6 was capable of utilizing cellulose, cellobiose, and glucose. Strain CTL-6 also grew with Sorbitol as the sole carbon source, whereas C. thermocellum is unable to do so.

Synthesis of hyperbranched copolymers by combining enzymatic ring-opening polymerization and ATRP from a novel bifunctional initiator

亢奋的分叉的脂肪族的聚酯 P (epsilon -CL) 借助于 BHB 的催化 Novozyme435 的戒指洞聚合(ROP ) 被综合(2， 2 二度(hydroxymethyl ) 奶油的酸) 。以 P ( epsilon-CL )的氢氧根结束的链被 esteriflcation ofa-bromopropionyl 溴化物修改获得亢奋的分叉的 difunctional 宏开始者，它在圣库克尔姆泰塔的 theATRP 被使用在 ATRP 的反应被用作催化剂系统 polystyrene-block-poly 获得 thehyperbranched 共聚物(2,2二度( hydroxymethyl )奶油的酸)。共聚物被 NMR 和 GPC 证实。

Gallic Acid/2-Hydroxypropyl-β-cyclodextrin Inclusion Complexes Electrospun Nanofibrous Webs:Fast Dissolution,Improved Aqueous Solubility and Antioxidant Property of Gallic Acid

Gallic acid(GA)is a kind of natural polyphenolic compound,but its low aqueous solubility restricts its application in the fields of food and medicine.Cyclodextrin can form inclusion complexes with guest molecules(e.g.,essential oils,food supplements)through cavities with special properties to improve aqueous solubility,thermal stability,and bioavailability of guest molecules.In this research,gallic acid/2-hydroxypropyl-β-cyclodextrin inclusion complexes(GA/2-HP-β-CD/ICs)were formed in a highly concentrated solution of 2-HP-β-CD.Bead-free and uniform nanofibrous webs(GA/2-HP-β-CD/IC-NWs)were produced successfully by electrospun GA/HP-β-CD/IC aqueous solution.The initial molar ratio(GA:2-HP-β-CD=1:1)of GA/2-HP-β-CD/IC in the solutions was largely maintained in GA/2-HP-β-CD/IC-NW.The aqueous solubility of GA was enhanced and GA/2-HP-β-CD/IC-NW has displayed fast dissolution property.Furthermore,in comparison with GA powder,GA/2-HP-β-CD/IC-NW demonstrated improved antioxidant capacity.The results suggested that GA/2-HP-β-CD/IC-NW have broad application prospects as orally fast dissolution systems for food supplements.

Synthesis of thermoresponsive polystyrene-based comb-type grafted poly(N-isopropylacrylamide)

Narrowly distributed polystyrene-g-p(N-isopropylacrylamide) (PSt-g-PNIPAM) was prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide using the brominated polystyrene as macroinitiator and CuCl combined with hexamethyltriethylenetetramine as catalyst. Fourier transform infrared (FT-IR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy confirmed the structure of PSt-g-PNIPAM. The gel permeation chromatography (GPC) showed that the graft copoly- mer had a single distribution peak with molecular weight, Mn (g/mol) of 19815 g/mol (using polystyrene as the standard). Differential scanning calorimetry (DSC) revealed that due to both effects of hydro- phobic isopropyl groups and hydrogen bonds in the amide group, the glass transition temperature (Tg) of PSt-g-PNIPAM enhanced 16.0 ℃ compared to the Tg of the polystyrene.

Rational design of robust iridium-ceria oxide-carbon nanofibers to boost oxygen evolution reaction in both alkaline and acidic media

Anodic oxygen evolution reaction(OER)is essential to participate in diverse renewable energy conversion and storage processes,while most OER electrocatalysts present satisfactory catalytic performance in only alkaline or acidic medium,limiting their practical applications in many aspects.Herein,we have designed and prepared Ir-CeO_(2)-C nanofibers(NFs)via an electrospinning and a relatively low-temperature calcination strategy for OER application in both alkaline and acidic conditions.Density functional theory(DFT)simulations demonstrate the high catalytic active sites of Ir atoms for OER,that the formation of Ir–O bonds at the interface between Ir and CeO_(2)can modulate the electron density of the relevant Ir atoms to promote the OER activity.In addition,the unique nanofibrous heterostructure increases the exposed active sites and promotes the electrical conductivity.Therefore,the prepared Ir-CeO_(2)-C nanofibrous catalyst delivers an excellent OER property in both alkaline and acidic solutions.Impressively,the overpotentials to reach 10 mA·cm^(−2)are only 279 and 283 mV in the alkaline and acidic electrolyte,respectively,with favorable long-term stabilities.In addition,the two-electrode overall water splitting set-ups equipped with Ir-CeO_(2)-C NFs as anode and commercial Pt/C as cathode provide a cell voltage of 1.54 and 1.53 V to drive 10 mA·cm^(−2)in the alkaline and acidic electrolyte,respectively,which are much lower than Pt/C||IrO_(2)and lots of transition metal oxides-based electrolyzers.This research presents an efficient means to design OER catalysts with superior properties in both alkaline and acidic solutions.

One-dimensional metallic, magnetic, and dielectric nanomaterialsbased composites for electromagnetic wave interference shielding

The excrescent electromagnetic(EM)radiation exposure in the air threatens human health and electronic equipment due to the abuse of EM waves in wireless telecommunication technology and electronic applications.Consequently,electromagnetic interference(EMI)shielding materials are provided to solve the EM waves pollution problem.In particular,the appearance of onedimensional(1D)metallic,magnetic,and dielectric nanofillers will extremely reduce the density of EMI composite and enhance EMI protection performance because they can easily assemble to form complete two-dimensional(2D)or three-dimensional(3D)EMI network based on their high aspect ratio,large specific surface area,and additional attenuated sites.This review focuses on the EMI shielding composites with 1D metallic,magnetic,and dielectric nanofillers,which could be constructed in the final form of membrane-or aerogel/sponge-like shielding materials.According to the structural features,1D metallic,magnetic,and dielectric nanofillers are classified into nanowires,nanorods,nanospindles,nanochains,nanofibers,nanotubes,nanorings,nanocoils,and quasi-one-dimensional(1D)van der Waals materials.Accordingly,the fabricated routes,shielding performances,and EM waves attenuation mechanism of the 1D metallic,magnetic,and dielectric nanofiller-based composites are summarized.It is found that the dominant shielding mechanism of most of the 1D metal-based EMI composites is reflection loss,while that of 1D magnetic and dielectric nanomaterials-based EMI composites is absorption loss caused by interfacial polarization,natural resonance,eddy current,and multiple scattering.Finally,the challenges and prospects of 1D nanofiller-based composites with a tunable architecture and composition are put forward,aiming to give a guideline for the next generation of high-performance EMI shielding materials.

Piezoelectric Nanogenerator Based on Electrospun Cellulose Acetate/Nanocellulose Crystal Composite Membranes for Energy Harvesting Application

Nanogenerators,as the typical conversion of mechanical energy to electrical energy devices,have great potential in the application of providing sustainable energy sources for powering miniature devices.In this work,cellulose acetate/cellulose nanocrystal(CA/CNC)composite nanofiber membranes were prepared by electrospinning method and then utilized to manufacture a flexible pressure-driven nanogenerator.The addition of CNC not only increased the content of piezoelectric cellulose I crystallization but also strengthened the mechanical deformation of the nanofiber membranes,which could greatly enhance the piezoelectric performance of CA/CNC composite membranes.The CA/CNC composite nanofiber membrane with 20%(mass fraction)of CNC(CA/CNC-20%)showed optimal piezoelectric conversion performance with the output voltage of 1.2 V under the force of 5 N(frequency of 2 Hz).Furthermore,the output voltage of the CA/CNC-20%nanogenerator device exhibited a linear relationship with applied impact force,indicating the great potential in pressure sensors.