Influence of Plastic and Coconut Shell (Cocos nucifera L.) on the Physico-Mechanical Properties of the 8/6 Composite Rafter

In this paper, the authors aim to propose the use of waste plastics as a binder in a coconut shell reinforcement for the development of an 8/6 size composite rafter to replace the natural 8/6 size backbone in construction. Following a study into the choice of the best proportions, a total of 30 size 8/6 composite rafters with different proportions of 20%, 25%, 30%, 35%, 40% and 50% plastic content were developed. All the 8/6 composite rafters were subjected to mechanical (3-point bending strength and Monnin hardness) and physical (bulk density and water absorption) characterization analyses. The results show that flexural strength increases from 27.56 MPa to 33.30 MPa for proportions ranging from 20% to 35% plastic content. Above 35% plastic, the strength drops to 19.60 MPa for a 50% plastic content. Similarly, the Monnin hardness drops from 9 mm to 5 mm when the plastic content varies from 20 to 50%. As for the results of the physical characterisation, the values obtained for apparent density vary from 0.89 to 1 for proportions varying from 20% to 35% plastic content and drop to 0.94 for 50% plastic content. As for water absorption, values drop from 6.82% to 2.45% when the plastic content increases from 20% to 50%. These mechanical strengths stabilise at 35% plastic content. The development of an 8/6 chevron composite material based on plastic and coconut shell could therefore be a way of recovering waste and solving the problem of deforestation.

ZrO_2薄膜的X射线光电子能谱分析

用X射线光电子能谱 (XPS)对自制ZrO2 薄膜进行了成分分析 .结果发现 ,在基片有负偏压的条件下 ,薄膜发生了氧缺位现象 ,退火处理可以补偿氧缺位 .在膜表面存在一个Y的偏聚层 .

Pt/Mo chalcogenide composite deriving from Pt-Mo_(6)S_8 by high temperature shock for enhanced HER performance

Highly efficient catalysts for electrolysis of water are crucial to the development of hydrogen energy which is helpful to carbon neutralization.Recently,high temperature shock(HTS),with advantage of rapid speed,universality and scalable production,has been a promising method in synthesis of nanomaterials.In this paper,HST was used to treat low Pt loading Mo_(6)S_(8)for enhanced water splitting performance.Impressively,the optimized MoS_(2)/MoO_(2)/Mo_(6)S_(8)nano-composite with low Pt mass loading(~4%)displays well hydrogen evolution reaction(HER)electrochemical performance.The overpotential is 124 mV to reach 10 mA/cm^(2)and the corresponding Tafel slope is 88 mV/dec in acidic electrolyte.Its mass activity is 6.2 mA/μg_(Pt)at-124 mV vs.RHE,which is almost 2 times relative to 20%Pt/C.Moreover,it presents distinguished stability even after 2000 cycles.This work will broaden the way of catalysts preparation and the application of hydrogen evolution.

NaV3O8/poly(3,4-ethylenedioxythiophene) composites as high-rate and long-lifespan cathode materials for reversible sodium storage

Sodium-ion batteries have received a surge of interests for the alternatives to lithium-ion batteries due to their abundant reserves and low cost.The quest of reliable and high-performance cathode materials is crucial to future Na storage technologies.Herein,poly(3,4-ethylenedioxythiophene)(PEDOT)was successfully introduced to NaV3O8 via in situ oxidation polymerization,which can effectively enhance electron conductivity and ionic diffusion of NaV3O8 material.As a result,these NaV3O8@-PEDOT composites exhibit a significantly improved electrochemical performance including cycle stability and rate performance.In particular,NaV3O8@20 wt%PEDOT composite demonstrates better dispersibility and lower charge transfer resistance compared with bare NaV3O8,which delivers the first discharge capacity of 142 mAh-g-1and holds about 128.7 mAh·g-1 after 300 cycles at a current density of 120 mA·g-1.Even at a high current density of 300 mA·g-1,a high reversible capacity of 99.6 mAh·g-1 is revealed.All these consequences suggest that NaV3O8@20 wt%PEDOT composite may be a promising candidate to serve as a high-rate and long-lifespan cathode material for sodium-ion batteries.

Poly(1,8-octanediol citrate)/bioactive glass composite with improved mechanical performance and bioactivity for bone regeneration

Poly（1,8-octanediol-co-citrate） （POC） represents a new promising biocompatible and biodegradable polyester that has been extensively investigated for soft tissue engineering. However, the poor mechanical performance and poor bioactivity limit its application in bone regeneration. In this study, a series of POC/bioactive glasses （BG） composites were developed using 45S5 Bioglass^Θ and a phytic acid- derived bioactive glass （referred as PSC）. The results indicated that calcium in BG could enhance the crosslinking of the POC/BG composites by forming calcium dicarboxylate bridges and thus improve their mechanical performances. When PSC were used, the composites exhibited significantly better mechanical properties compared to composites with 45S5 Bioglass^Θ. For example, by incorporating 70wt% PSC, the compressive strength of POC/PSC composites could be improved to approximately 50 MPa and modulus 1.3-h 0.1 GPa. Furthermore, all these POC/PSC composites showed good in vitro bioactivity and cellular biocompatibility. Histology results in femoral condyle defects of Sprague-Dawley rats indicated that the POC/PSC samples integrated well with surrounding tissues and stimulated bone regeneration. The improved mechanical properties and bioactivity of POC/PSC composites make them promising for potential application in bone regeneration.