Thermal degradation of rice straw fibers: Global kinetic modeling with isothermal thermogravimetric analysis

Qinglin Wu,Fei Yao,Xinwu Xu,Changtong Mei,Dingguo Zhou 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

Thermal degradation behavior of rice straw fibers under isothermal heating conditions was studied. The data were modeled by considering the fiber as one pseudo-component using the Malek method. The kinetic model with reaction order n > 1 [i.e., RO(n > 1) = (1-a)n] described the degradation process of rice straw fiber fairly well in a temperature range up to about 265 8C. The kinetic parameters used include activation energy of 116±5 kJ/mol, reaction order of 3.0±0.2, and logarithmic value of preexponential factor [ln A] of 18.7 ±0.1 ln s-1. The model obtained can be used to aid the development of straw fiber-engineering plastic composites.

Design of Protein Sequences with High Strength and Toughness Based on Generative Adversarial Networks

Qinglin Wu,Dong Chen 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

Flame retardancy and thermal degradation behavior of red gum wood treated with hydrate magnesium chloride

Yiqiang Wu,Chunhua Yao,Yunchu Hu,Shoulu Yang,Yan Qing,Qinglin Wu 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.5

Flame retardancy and thermal degradation of wood treated with magnesium chloride (MgCl2 6H2O) were investigated. Results showed that MgCl2 6H2O decreased flame intensity and heat release rate, and reduced smoke concentration and gas yield. From ambient temperature to 250 ℃, MgCl2 6H2O reduced wood combustibility by gas dilution mechanism. The chemical started to decompose at 350 8C and produced MgOHCl, in which -Cl and -Mg free radicals were generated and intervened the chain reactions of wood combustion. Hydrogen chloride gas generated promoted wood charring. MgCl2 6H2O gradually converted to MgOHCl and MgO compounds at higher temperatures, and MgO suppressed wood combustion by the wall effect mechanism.

A unique “fishtail-like” four-way shape memory effect of compositionally graded NiTi

Meng, Qinglin,Wu, Zhigang,Bakhtiari, Reza,Shariat, Bashir S.,Yang, Hong,Liu, Yinong,Nam, Tae-hyun Elsevier 2017 Scripta materialia Vol.127 No.-

<P><B>Abstract</B></P> <P>This paper reports a complex four-way shape memory effect of a compositionally graded NiTi thin plate. The composition gradient is created by surface diffusion of Ni into the plate. After a 15% tensile deformation pre-treatment, the compositionally graded plate exhibits a complex four-way shape memory effect in bending mode, by which the metal exhibits a back-and-forth shape change upon a complete thermal cycle. This is analogous to a “fishtail-like” motion, resulting from the sequential transformation through the thickness of the plate as dictated by Ni content gradient. Such “four-way” shape memory effect has not been achieved in NiTi alloys before.</P> <P><B>Graphical abstract</B></P> <P>Complex “4-way” shape memory behaviour of a compositionally graded NiTi thin strip after 15% of tensile deformation. In this figure, the sample bends towards one direction (increase of curvature) initially and then bends backwards (decrease of curvature) upon one cooling (the blue curve). The same process repeats also during heating, thus exhibiting shape change in four directions within one complete thermal cycle.</P> <P>[DISPLAY OMISSION]</P>

Thermal degradation and flammability behavior of fire-retarded wood flour/polypropylene composites

Sun, Lichao,Wu, Qinglin,Xie, Yanjun,Cueto, Rafael,Lee, Sunyoung,Wang, Qingwen Technomic Publising 2016 Journal of Fire Sciences Vol.34 No.3

<P>Magnesium hydroxide, expandable graphite, and ammonium polyphosphate were used to enhance the thermal stability and fire retardant properties on wood flour/polypropylene composites. The thermal decompositions and flammability properties were investigated using modulated thermogravimetric analysis and cone calorimeter, and the activation energy of each decomposition process was also determined by modulated thermogravimetric analysis. The results showed that both expandable graphite and ammonium polyphosphate promoted thermal degradation of wood flour and char formulation, and magnesium hydroxide did not influence on the wood flour decomposition. Unlike in nitrogen atmosphere, magnesium hydroxide and ammonium polyphosphate increased the peak temperature of wood flour thermal degradation and diminished the decomposition peaks of polypropylene in air atmosphere. Cone calorimeter results showed that expandable graphite greatly reduced the heat and smoke release. A general activation energy range of 187-226kJmol(-1) (in nitrogen), 165-206kJmol(-1) (in air) at wood flour degradation stage, 237-262kJmol(-1) (in nitrogen), and 185-269kJmol(-1) (in air) at polypropylene degradation stage were proposed for wood flour/polypropylene composite with and without fire retardants.</P>

Rheology, curing temperature and mechanical performance of oil well cement: Combined effect of cellulose nanofibers and graphene nano-platelets

Sun, Xiuxuan,Wu, Qinglin,Zhang, Jinlong,Qing, Yan,Wu, Yiqiang,Lee, Sunyoung Elsevier 2017 Materials & Design Vol.114 No.-

<P><B>Abstract</B></P> <P>Cellulose nanofibers (CNFs) were prepared through acid hydrolysis and used in combination with graphene nano-platelets (GNPs) as modifiers for oil well cement (OWC). The rheology behavior of CNF/GNP-OWC slurries at three temperatures (i.e., 20, 40, and 60°C) was measured and modeled using four different rheological models. Thermal properties, surface functional groups, morphology, and mechanical performance of the composites were characterized. CNF/GNP-OWC slurry exhibited a typical shear-thinning behavior with reduced shear viscosity at higher shear rates. The use of CNFs and GNPs led to increased yield stresses of fresh CNF/GNP-OWC slurry and temperature significantly influenced the yield stress values. Among these rheology models, the Vom Berg model exhibits the best fitting result of the slurry rheology data (R<SUP>2</SUP> =0.999). The addition of CNFs and GNPs increased degree of hydration (DOH) value of CNF/GNP-OWC composites. Both flexural and compressive strengths of the CNF/GNP-OWC composites were enhanced with added CNFs and GNPs. The reinforcing mechanism was attributed to the increased DOH, reduced pores, and bridging effect of CNFs and GNPs in the composites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cellulose nanofibers (CNFs) and graphene nanoplatelets (GNPs) reinforced oil well cement (OWC) composites were prepared and characterized. </LI> <LI> Vom Berg model provided the best fitting to measured rheology data of OWC slurry. </LI> <LI> CNFs and GNPs enhanced flexural and compressive strengths of OWC. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Design, Simulation and Rapid Manufacturing of Plate Micro Reactor

Shikai Zhang,Qinglin Wu,Dong Chen 한국고분자학회 2022 한국고분자학회 학술대회 연구논문 초록집 Vol.47 No.1

Functionally graded shape memory alloys: Design, fabrication and experimental evaluation

Shariat, Bashir S.,Meng, Qinglin,Mahmud, Abdus S.,Wu, Zhigang,Bakhtiari, Reza,Zhang, Junsong,Motazedian, Fakhrodin,Yang, Hong,Rio, Gerard,Nam, Tae-hyun,Liu, Yinong Elsevier 2017 Materials & Design Vol.124 No.-

<P><B>Abstract</B></P> <P>Functionally graded shape memory alloys have the advantage of combining the functionalities of the shape memory effect and those of functionally graded structures. By proper design, they can exhibit new and complex deformation behaviour that is unmatched in uniform shape memory alloys. One obvious advantage of functionally graded shape memory alloys is their widened transformation stress and temperature windows that provide improved controllability in actuating applications. This paper reports on the concept, fabrication, experimentation and thermomechanical behaviour of several designs of functionally graded NiTi alloys, including compositionally graded, microstructurally graded and geometrically graded NiTi alloys, and the various techniques that may be used to create these functionally graded materials. It is found that the property gradients created along the loading direction or perpendicular to the loading direction produce distinct thermomechanical behaviours. The property gradient along the loading direction provides stress gradient over stress-induced transformation, which can be adjusted by the property gradient profile. The property gradient through the thickness direction of plate specimens and perpendicular to the loading direction provides four-way shape memory behaviour during stress-free thermal cycling after tensile deformation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Functionally graded shape memory alloys provide widened transformation stress and temperature windows in actuation application. </LI> <LI> The property gradient was achieved in three ways: microstructural gradient, compositional gradient and geometrical gradient. </LI> <LI> Property gradients created along the loading direction or perpendicular to that direction produce distinct thermomechanical behaviours. </LI> <LI> A variety of techniques has been proposed for fabricating functionally graded shape memory alloy structures. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Soy Protein Isolate As Fluid Loss Additive in Bentonite–Water-Based Drilling Fluids

Li, Mei-Chun,Wu, Qinglin,Song, Kunlin,Lee, Sunyoung,Jin, Chunde,Ren, Suxia,Lei, Tingzhou American Chemical Society 2015 ACS APPLIED MATERIALS & INTERFACES Vol.7 No.44

<P>Wellbore instability and formation collapse caused by lost circulation are vital issues during well excavation in the oil industry. This study reports the novel utilization of soy protein isolate (SPI) as fluid loss additive in bentonite–water based drilling fluids (BT-WDFs) and describes how its particle size and concentration influence on the filtration property of SPI/BT-WDFs. It was found that high pressure homogenization (HPH)-treated SPI had superior filtration property over that of native SPI due to the improved ability for the plugging pore throat. HPH treatment also caused a significant change in the surface characteristic of SPI, leading to a considerable surface interaction with BT in aqueous solution. The concentration of SPI had a significant impact on the dispersion state of SPI/BT mixtures in aquesous solution. At low SPI concentrations, strong aggregations were created, resulting in the formation of thick, loose, high-porosity and high-permeability filter cakes and high fluid loss. At high SPI concentrations, intercatlated/exfoliated structures were generated, resulting in the formation of thin, compact, low-porosity and low-permeability filter cakes and low fluid loss. The SPI/BT-WDFs exhibited superior filtration property than pure BT-WDFs at the same solid concentraion, demonstrating the potential utilization of SPI as an effective, renewable, and biodegradable fluid loss reducer in well excavation applications.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2015/aamick.2015.7.issue-44/acsami.5b07883/production/images/medium/am-2015-07883j_0012.gif'></P>

Cellulose Nanocrystals and Polyanionic Cellulose as Additives in Bentonite Water-Based Drilling Fluids: Rheological Modeling and Filtration Mechanisms

Li, Mei-Chun,Wu, Qinglin,Song, Kunlin,De Hoop, Corneils F.,Lee, Sunyoung,Qing, Yan,Wu, Yiqiang American Chemical Society 2016 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.55 No.1

<P>This research aims to develop low cost, sustainable, environmentally friendly, and high performance water-based drilling fluids (WDFs) using bentonite (BT), polyanionic cellulose (PAC), and cellulose nanocrystals (CNCs). The effect of concentration of BT, PAC, and CNCs on the rheological and filtration properties of PAC/CNC/BT-WDFs was investigated. Eight empirical rheological models were applied to fit quantitatively the fluid properties. Results showed that the presence of PAC, CNCs, and BT improved the rheological and filtration properties of the WDFs. Among the eight empirical rheological models, the Sisko model performed the best in simulating the rheological behavior of the fluids. At the same concentration level of PAC and CNCs, CNCs had more impact on the rheological properties, whereas PAC had more influence on the filtration property. The incorporation of PAC resulted in very low permeable filter cakes, leading to the excellent filtration property. The combined use of PAC and CNCs yielded better rheological and filtration properties.</P>