Table of contents

Thanks to Prof. Tien-Chien Jen, the Chair Professor at Anhui Agriculture University and the Director of UJ-Nanjing Tech Joint Research Center in China, for assisting Modern International Green Cultural Communication Association (MIGCCA) to successfully hold the 2021 International Conference on Polymeric, Metallic and Composite Materials (PMCM 2021) during May 29-30, 2021 in Wuhan, China

In light of the worldwide outbreak of COVID-19, there were only 20 people present at the meeting. In such a small academic conference, all participants have more opportunities to communicate and build relationships with other scholars. At the meeting, Prof. Abd El-Fatah Abomohra, as the keynote speaker, made a speech to discuss the potential uses of microalgae in human health, wastewater treatment and biofuels. Dr. Kinjal J. Shah, who was not available to attend the conference in China, sent us a prerecorded talk, which made the form of participation more diversified. Meanwhile, we highly encouraged doctorate (PhD) and postgraduate students to present their research proposal and findings in this conference. With the concerted efforts of us all, the conference has been a complete success and contributed significantly to promoting dialogue and exchanges among scholars and researchers to report most recent innovations and developments, summarize state-of-the-art, and exchange ideas and advances in the aspects of polymeric, metallic and composite materials.

List of PMCM 2021 Organizing Committee, List of Committees, International Reviewers are available in this pdf.

All conference organisers/editors are required to declare details about their peer review. Therefore, please provide the following information:

• Type of peer review: Single-blind / Double-blind / Triple-blind / Open / Other (please describe)

Double-blind peer review: All submitted full papers have been peer-reviewed by two reviewers. The acceptance would be granted if the recommendations from the reviewers were positive. The criteria are based on the technical criteria, quality criteria, presentation criteria and format. Authors should make sure the submitted papers use the template for this conference.

• Conference submission management system:

Submit to the conference mailbox as an attachment

• Number of submissions received:

35 submissions received

• Number of submissions sent for review:

35 submissions were sent for review

• Number of submissions accepted:

17 submissions are accepted

• Acceptance Rate (Number of Submissions Accepted/Number of Submissions Received X 100):

48.6%

• Average number of reviews per paper:

Average two reviews per paper

• Total number of reviewers involved:

45 reviewers

• Any additional info on review process:

The conference organisers evaluated each submission to determine if its topic and content are suitable for consideration before being reviewed. Manuscripts that do not meet the conference topic were returned to the authors.

Submissions that passed the initial review would be sent to two or three referees based on their expertise. The reviewers were asked to evaluate the manuscript based on its originality, significance, technical quality, relevance and completeness, and to complete their reviewing work (review form and revised draft) within two weeks. After collecting the referees' reports, the conference organisers would make a recommendation on the acceptability of the manuscript.

The final recommendation can be 1) Paper accepted for publication without changes (only in case at least 7 out of 13 criteria were evaluated positive and no criterion was evaluated negative); 2) Paper accepted for publication after modification; 3) Paper not eligible for publication (obligatory in case at least 7 out of 13 criteria were evaluated negative). If the paper requires corrections, the reviewer would specify suggested remarks and comments for the author(s). Then the conference organisers would sent the remarks and comments to the author(s).

• Contact person for queries (please include: name, affiliation, institutional email address)

Emma FONG

Modern International Green Culture Communication Association (MIGCCA)

No. 888, Xiong Chu Road, Hongshan District, Wuhan, Hubei, China

icmed2017@outlook.com; emma@migcca.com

The influence of steel fiber on the mechanical properties of ultra-high performance concrete (UHPC) were studied through slump, compressive strength, flexural strength test. The experimental results showed that the incorporation of steel fiber had an influence on the working performance of UHPC, and the slump and expansion degree of UHPC were inversely proportional to the volume content and length-diameter ratio of steel fiber. The steel fiber significantly improved the compressive and flexural strength of UHPC. The mechanical property of UHPC was the best when the steel fiber content was 4%, with 28 day compressive strength up to 163.2MPa and flexural strength up to 45.9MPa. UHPC showed a trend of gradual decrease of compressive strength and gradual increase of flexural strength with the increase of aspect ratio of steel fiber on the condition of constant volume content of steel fiber. The addition of special-shaped steel fiber can improve the compressive and flexural strength of UHPC effectively.

As the tube materials of receiver in the solar tower power plant, molten salt corrosion behavior of Incoloy 840 has been studied. In this work, after Incoloy 840 samples were deposed separately in molten Solar Salts (40wt.% KNO₃ + 60wt.% NaNO₃) at 560°C for different times (5, 10, 15, 20, 30, 40, 60 and 80h), the weight-loss of samples were measured, the metallurgical structure of as-received Incoloy 840 was observed by optical microscope, the metallurgical structure of corroded films on the samples were observed by SEM, the corrosion products chemistries of the oxide film were analyzed by EDS and XRD. The results showed that the corrosion kinetics of the Incoloy 840 follows typical parabolic rule at 560°C in mixture molten salts (40wt.% KNO₃ + 60wt.% NaNO₃), and the corrosion rate of Incoloy 840 is 12.3 μm/year. The corroded films had a bilayer structure, the outer layer consists of Fe₂O₃, and the inner layer consists of γ-(Fe, Ni) and Cr₂O₃.

To determine the relations of performance and structure accurately, polyphosphazenes with various substitution rates of phenoxy and ethoxy were prepared by nucleophillic substitution reaction, their structures and glass transition temperature (Tg) were characterized by NMR and DSC, respectively, and theoretical Tg of polyphosphazenes containing various structural units were calculated by Fox equation. We can find that Tg of polyphosphazenes decreased with increase of ethoxy contents, which improved low temperature resistance of the polymer. According to the measured value and calculated value of Tg, as well as the deduced mathematical expression of Tailor-Gorden equation, the relationships between Tg and ethoxy contents were proposed, which demonstrated that a plot of the Tg vs. ethoxy contents yielded straight lines when polymer chain owned higher substitution rates of phenoxy or ethoxy, while Tg of polymers with more structural units of phenoxy and ethoxy would be adjusted by a parameter of ωB. Based on the proposed relation, the application of fabrication on polyaryloxyphosphazene elastomer with better mechanical properties and low temperature resistance was successfully carried out. Therefore, the proposed methods can be useful in the prediction of polymer Tg and can also be used for structure prediction of polymers to match a target Tg value by this means, which are likely to have broad applications in polymer science fields.

Cerium oxide (CeO₂) modified natural rubber (NR) exhibits good mechanical properties, such as high abrasion resistance, high tear strength and good thermal aging and creep resistance. Rubber components are often subjected to long-term cyclic loading in service. Therefore, fatigue performance needs to be considered for their application. In the investigations, tensile properties and fatigue properties of CeO₂ modified vulcanised NR under uniaxial loading were investigated. The fatigue tests were carried out under constant cyclic strain range at room temperature. Results showed that the CeO₂ modified NR demonstrated higher elastic modulus and larger elongation than that of unmodified rubber, which were related to the enhanced interaction and bonding force of rubber chains by CeO₂ additive. Moreover, a remarkably enhanced fatigue life could be achieved in the CeO₂ modified NR. The internal friction and impact in the rubber matrix was relieved by CeO₂ additive, which can reduce the hysteresis loss during cyclic loading, resulting in improved fatigue resistance in CeO₂ modified vulcanised NR.

The polycrystalline ZnO thin films have been deposited on p-Si(100) substrate with a native SiO₂ layer by radio frequency magnetron sputtering. The photoinduced position sensitivity of the ZnO thin film/SiO₂/Si heterojunction has been investigated. The resistance relative change ratio of ZnO/SiO₂/Si was about 1041% at 1.0 bias voltage when the different positions of the heterojunction surface were illuminated by a He-Ne laser with 5 mW power and 50 μm diameter spot. A gradient distribution of light-generated electrons in the sample varied with the location of the light spot. The reason was that the distribution of carrier density is different between the illuminated and unilluminated location.

It is of great importance to investigate the doped TiO2 photocatalyst for the better photocatalytic activity via visible light. In this study, a newly Ag·AgBr@TiO₂ photocatalyst has been prepared via a facile sol-gel process using n-butyl titanate as titanium source, silver nitrate as silver source, and potassium bromide as bromine source. The different nano porous catalyst products were prepared by using of calcining precipitates (obtained by drying the sol-gel in an oven at 80°C) in air at 300, 480, and 660 °C for 3 hours respectively. The selected precursor treatments and heterostructure display significantly improved photodegradation activity on organic 2-naphthol. The microstructures were characterized by XRD and SEM. The results showed that TiO₂ and doped TiO₂ are both anatases generally. Compared with those of undoped TiO₂ and AgBr, the Ag, AgBr-doped TiO₂ has remarkably enhanced photocatalytic activity towards 2-naphthol. Owing to the higher absorption of Ag, AgBr nanoparticles on to the TiO₂, the excellent photocatalytic activities of Ag·AgBr@TiO2 were obtained. The degradation rates of 2-naphthol reached 69% under Ag, AgBr-doped TiO₂ photocatalyst, whereas, with undoped TiO₂ and pure AgBr, the degradation rates of 2-naphthol are 20% and 43% respectively.

Employing thiourea as precursor, the bulk graphitic carbon nitride (named SCN) was prepared via thermal polymerization strategy. The SCN was then stripped and treated by different concentrations of NaOH solution, and then porous carbon nitride SCN with loose structure was obtained and characterized by X-ray diffraction (XRD), N₂ adsorption, scanning electron microscope (SEM), transmission electron microscopy (TEM), photoluminescence (PL). Then catalytic performance of the obtained porous carbon nitride SCN samples was evaluated by degrading methyl blue solution (MB). The results show that the normal pressure alkaline treatment is an effective way to prepare porous carbon nitride. After being treated by NaOH solution of 0.3 mol/L, the specific surface area of SCN increased to three times than that of bulk SCN. The synergistic effect of adsorption and photocatalysis boosts the photocatalytic efficiency of SCN by 1.78 times compared with bulk SCN, and the first-order reaction rate constant K_app is increased by 2.9 times.

To investigate the microstructure evolution and mechanical properties of materials treated by friction stir processing process at various the shoulder sizes and rotating speeds of the tool, a series of friction stir processing experiments were carried out on the AZ31 magnesium alloy with thickness of 4mm by using tool shoulder sizes of 12, 16 and 18mm, and two kinds of rotating speeds of 750r/min and 1500r/min with a constant feed speed of 60mm/min were supplied. Based on the analysis of morphology and mechanical properties of the materials, results demonstrated that reduction of tool shoulder size and rotating speed would contribute to more remarkable the grain refinement effect and affect the strong texture and extreme density strength of the material, leading to higher microhardness. However, lower mechanical properties of yield strength and tensile strength were obtained at these parameters owing to the existence of internal organization defect and stronger defect sensitivity of it. All of the findings would further deepen the understanding of the technique of friction stir processing and contribute to the application of AZ31 magnesium alloy treated by friction stir processing.

Acoustic emission (AE) testing has been an active area of research globally for many decades. The present work is a comprehensive overview based on bibliometric analysis to investigate the application of AE research. The publication trends, key areas, organizations, countries, and sources and publications of AE applications are presented to address the following basic questions: what are the publication sources and trends, what are the key areas, and which countries and organizations are active in AE research? The influences of various AE subjects and topics are also discussed. With the help of the Web of Science Core Collection database and the specialized bibliometric analysis tool VOSviewer, the results are visualized properly, and it is found that AE research is currently developing rapidly.

In order to heighten their near infrared light-sensitive characteristics, lead phthalocyanine (PbPc) phototransistors were prepared by vacuum evaporation at various substrate temperatures (T_s) of 60°C, 100°C, 140°C and 180°C. The crystalline texture, absorption spectrum and surface morphology of PbPc films were measured. The light-sensitive characteristic measurement results indicated that the photoresponsivity (R) and specific detectivity (D^*) of the devices first rise and dwindle as T_s grows and a best performance is gained at T_s = 100°C. Research on the correlation between substrate-temperature-dependent film properties and device performance showed that the crystal texture, interconnection of grains, light absorption and carrier mobility of PbPc films could be varied by substrate heating, and thereby causing the variations in the device performance for R and D^*. Moreover, a model semi-quantitatively describing the variation of photocurrent with optical absorption coefficient and carrier mobility was set up, and some numerical calculations were made base on the model presented.

In this work, co-implantation of silver and tantalum on TiN coated Ti-6Al-4V surface was carried out by an omnidirectional ion implantation system. The effects of Ag/Ta co-implantation on its biological properties and antibacterial activity were studied. The elemental content was determined by XPS, the biocompatibility was determined by Fibroblast-like cells (L929) and the antimicrobial activity was determined by Escherichia coli (E. coli). The results indicated that Ag/Ta-TiN coating exhibited the good biocompatibility and excellent antibacterial properties, which means that Ag/Ta co-implantation can improve the biocompatibility and antibacterial properties of Ti-6Al-4V.

In this study, three kinds of polyurethane materials based on HTPB were prepared by copolymerization of hydroxyl-terminated polybutadiene (HTPB) and hydroxyl-terminated polyethylene glycol-tetrahydrofuran copolyether (HTPE) and adding mixed chain extender, polyether polyols HEP-330N and 2-hydroxyethyl disulfide (HEDS). The effects of copolymerization and mixed chain extender on the mechanical properties of polyurethane were studied by static tensile test, dynamic mechanical property analysis (DMA) and differential scanning calorimetry (DSC). Among them, compared with pure HTPB, the tensile strength and elongation at break of polyurethanes obtained by copolymerization, the polyurethanes obtained by adding mixed chain extender, and the polyurethanes obtained by both of these two methods were significantly improved, and the storage modulus and loss modulus were also improved. In addition, the glass transition temperature of polyurethane remained basically unchanged, which was in the range of -79°C to -75°C. It was much lower than the room temperature, which would make it more widely used. This effective method will provide an opportunity for the synthesis of various high-performance composites.

To reveal the influencing factors and mechanism of adsorption of heavy metal Cd by biochar, different elution solvents (water and dilute acid solution) were used in this paper to elute the residual ash substances after pyrolysis of biochar, then the pH was regulated to investigate the adsorption effect of biochar on Cd in different treatment conditions. The precipitation experiments of Cd by biochar soaking and washing filtrate showed that the precipitation of root, stem and leaf of Acorus calamus L. contributed a great deal to the heavy metal removal system, which accounting for 81%, 77% and 98%, respectively, and the adsorption effect of biochar of roots, stems and leaves of Acorus calamus L. on Cd was slightly increased after washing. The adsorption experiment of biochar pickling on heavy metals showed that the adsorption effect of biochar on heavy metals Cd decreased greatly after pickling, which may be due to the removal of most of the minerals on the surface of biochar after pickling and the decrease of pH value of biochar. This work can provide insights into the use of biochar to control Cd.

Dry sliding wear testing of Ti-6Al-4V alloy was performed at temperatures of 20, 100 and 200°C to investigate it's wear transition mechanism. Each wear rate-applied load curve demonstrated a mild wear stage and a severe wear stage. Morphology and composition of worn surface were analyzed using SEM and EDS techniques. When wear transformed from the mild wear stage to severe wear stage, sever plastic deformation wear mechanism played a dominant role. The analysis of subsurface microstructures revealed that a fine grain microstructure zone was formed beneath the surface after mild to severe wear transition, correspondingly a soften effect was detected in the fine grain microstructure zone by microhardness measurement. Therefore, it is considered that the softening in the near surface is the main reason for mild to severe wear transition.

This paper investigates three approaches for detecting the content of styrene-butadiene-styrene (SBS) in its modified asphalt. The physical, rheological, and structural analysis are respectively conducted by the conventional tests, dynamic shear rheology, and Fourier transform infrared spectroscopy (FTIR) tests. The results show that the fitting coefficient of the quadratic equation between the SBS content and viscosity or softening point or phase angle is very high, but these tests are time-consuming. The absorption peak at 966 cm^-1 (the absorption peak area of 966 cm^-1 is marked as A966, the same below) is selected as the characteristic peak of SBS, and the absorption peaks of 1377 cm^-1, 811 cm^-1 and 749 cm^-1 are selected as the characteristic peak of the base asphalt in SBS modified asphalt. Comparing the applicability, accuracy and sensitivity of A₉₆₆/A₁₃₇₇, A₉₆₆/A₈₁₁, and A₉₆₆/A₇₄₉, it is found that A₉₆₆/A₈₁₁ is more suitable as the indicator to determine the content of SBS. FTIR can realize the rapid and accurate detection of SBS content. Furthermore, A₉₆₆/A₈₁₁ has a good quadratic relationship with the performance of the modified asphalt.

To enhance and lengthen the anti-aging performance and service lifetime of bitumen, 3-methacryloxypropyltrimethoxysilane grafted layered double hydroxides (LDHs) was synthesized and exploited to modify bitumen. The contact angle of organic LDHs (OLDHs) increased from 17.8° to 39.2°, the hydrophilic of OLDHs obviously decreased in comparison with LDHs, which contributed to disperse more uniformly in bitumen. Furthermore, the stability of LDHs in bitumen became better after 3-methacryloxypropyltrimethoxysilane modification. After aging, the penetration and ductility of bitumen markedly declined, correspondingly, the softening point and viscosity remarkably rose, the physical performance of bitumen were deteriorated seriously. The addition of LDHs and OLDHs could restrain the properties degradation after aging, enhance the anti-aging of bitumen, and OLDHs exhibited much more excellent, because of the outstanding stability in bitumen.

With the modification of crumb rubber (CR), the viscosity and elasticity of asphalt binder will be significantly enhanced. This study used waste cooking oil (WCO) to adjust the chemical fractions in the prepared CR modified asphalt binder (CRMA) for the purpose of reaching a better viscoelastic behavior. Further, the viscoelastic behavior of CRMA incorporated with 4% WCO was investigated and evaluated by constructing reliable master curves from outputs of the classical Christensen-Anderson model. The findings obtained indicated that the use of 4%WCO into CRMA binder just causes a limited decrease of the complex modulus, and in this case, the resulting binder still remains applicable to stand with the resistance to deformation from outside repeated forces; both raising temperature and incorporating WCO can be able to produce similar effects on the viscoelastic transition of CRMA binder approaching to higher frequency; once the environmental condition surpasses the viscoelastic transition temperature of CRMA binder, or WCO is added, the viscous behavior will be switched to a lower temperature; the Christensen-Anderson model is verified available and supportively recommended for viscoelastic analyses of binders.

Please see Article PDF for corrigendum text.