Search results
1 – 10 of 41Chao Ye, Xiufang Wen, Jia-ling Lan, Zhi-qi Cai, Pi-hui Pi, Shou-ping Xu and Yu Qian
The purpose of this paper is to modify light hollow polymer microsphere (LHPM) with titanium dioxide nanoparticles (nano-TiO2) to improve its compatibility with latex and apply…
Abstract
Purpose
The purpose of this paper is to modify light hollow polymer microsphere (LHPM) with titanium dioxide nanoparticles (nano-TiO2) to improve its compatibility with latex and apply the obtained nano-TiO2/LHPM composite particles in external wall thermal insulation coatings.
Design/methodology/approach
The nano-TiO2/LHPM composite particles were prepared via vigorous stirring. The morphology and chemical composition of the produced nano-TiO2/LHPM composite particles were characterized using scanning electron microscopy, energy dispersion spectrum, thermo-gravimetric analyzer and Fourier transform infrared. The performance of this new composite coating was evaluated by checking its stability, density, radiation reflectivity, thermal conductivity and the resulting insulation temperature difference when forming coating film.
Findings
It was found that a 9:1 mass ratio of nano-TiO2/LHPM with total 10 weight per cent composite particles in the thermal insulation paint showed low density, good stability, low thermal conductivity (0.1687 W/m·K) and high insulation temperature difference (5.8°C).
Research limitations/implications
The LHPM can be modified by other nanoparticles to improve its insulation performance in thermal insulation coatings.
Practical implications
This work provides a simple, robust, but effective approach to produce new thermal insulation coatings with nano-TiO2/LHPM composite particles.
Originality/value
This method for surface modification of LHPMs is novel and the modified hollow polymer microspheres could be applied to external wall insulation coatings.
Details
Keywords
Amirul Syafiq, Farah Khaleda Mohd Zaini, Vengadaesvaran Balakrishnan and Nasrudin Abd. Rahim
The purpose of this paper is to introduce the simple synthesis process of thermal-insulation coating by using three different nanoparticles, namely, nano-zinc oxide (ZnO)…
Abstract
Purpose
The purpose of this paper is to introduce the simple synthesis process of thermal-insulation coating by using three different nanoparticles, namely, nano-zinc oxide (ZnO), nano-tin dioxide (SnO2) and nano-titanium dioxide (TiO2), which can reduce the temperature of solar cells.
Design/methodology/approach
The thermal-insulation coating is designed using sol-gel process. The aminopropyltriethoxysilane/methyltrimethoxysilane binder system improves the cross-linking between the hydroxyl groups, -OH of nanoparticles. The isopropyl alcohol is used as a solvent medium. The fabrication method is a dip-coating method.
Findings
The prepared S1B1 coating (20 Wt.% of SnO2) exhibits high transparency and great thermal insulation property where the surface temperature of solar cells has been reduced by 13°C under 1,000 W/m2 irradiation after 1 h. Meanwhile, the Z1B2 coating (20 Wt.% of ZnO) reduced the temperature of solar cells by 7°C. On the other hand, the embedded nanoparticles have improved the fill factor of solar cells by 0.2 or 33.33%.
Research limitations/implications
Findings provide a significant method for the development of thermal-insulation coating by a simple synthesis process and low-cost materials.
Practical implications
The thermal-insulation coating is proposed to prevent exterior heat energy to the inside solar panel glass. At the same time, it can prevent excessive heating on the solar cell’s surface, later improves the efficiency of solar cell.
Originality/value
This study presents a the novel method to develop and compare the thermal-insulation coating by using various nanoparticles, namely, nano-TiO2, nano-SnO2 and nano-ZnO at different weight percentage.
Details
Keywords
P.K. Sahu, P.A. Mahanwar and V.A. Bambole
The purpose of this paper is to prepare heat insulating exterior emulsion coating and to study its heat insulating property along with mechanical, chemical and weathering…
Abstract
Purpose
The purpose of this paper is to prepare heat insulating exterior emulsion coating and to study its heat insulating property along with mechanical, chemical and weathering resistance properties with varying amount of hollow glass microspheres and cenospheres.
Design/methodology/approach
For heat insulating effect, various compositions were made by incorporating different proportions of hollow glass microspheres (HGM) and cenospheres (C). The mechanical, chemical, morphological and optical properties of the coating films were studied and compared.
Findings
Addition of hollow glass microspheres and cenospheres enhanced heat insulating property of the coating, hardness, tensile strength and wet scrub resistance. It was evaluated that optimum loading for both cenospheres and hollow glass microspheres was 10 wt.% and both the systems showed good mechanical, chemical resistance and weathering properties.
Practical implications
Addition of hollow glass microspheres and cenospheres to acrylic emulsion coating is a simple and inexpensive method.
Originality/value
The new heat insulating coatings with good thermal insulation properties and improved weather resistance were prepared. These coatings could find applications in demanding fields such as exterior wall coatings and roof coatings.
Details
Keywords
Baolong Wang, Haiqing Ma, Di Wu, Lien Zhu and Zheng Jin
The purpose of this paper is to prepare new modified polypropylene (PP) with phenolic microspheres (PFMs). Furthermore, the crystallinity and mechanical properties of PP modified…
Abstract
Purpose
The purpose of this paper is to prepare new modified polypropylene (PP) with phenolic microspheres (PFMs). Furthermore, the crystallinity and mechanical properties of PP modified by fillers (silicon dioxide [SiO2] and light calcium carbonate [CaCO3], respectively) have also been investigated and compared.
Design/methodology/approach
For effective toughening, three different fillers were added into the PP matrix. PP composites were prepared through melt blending with double-screw extruder and injection moulding machine.
Findings
It was found that with the addition of 3 Wt.% PFM, the impact strength was maximum in all PP composites and increased by 1.4 times compared to pure PP. Scanning electron microscopy (SEM) and polarised optical microscopy (POM) analysis confirmed that 3 Wt.% PFM, 3 Wt.% SiO2 and 2 Wt.% CaCO3 were optimal to add in PP and PFM to give the best compatibility with PP.
Research limitations/implications
PFM particles not only are tougher and less brittle and can offer other advantages such as enhanced machinability, but also are important organic materials and have a good compatibility with polymer for reinforcing polymer properties.
Practical implications
The method developed provided a simple and practical solution to improving the toughness of PP.
Social implications
There will be thermoplastic plastics with higher toughness in domestic, packaging and automotive applications, particularly at lower temperatures.
Originality/value
The PP modified by tiny amounts of fillers in this work had high toughness, which can be applied as an efficient material widely used in domestic, packaging and automotive applications.
Details
Keywords
Abstract
Purpose
Additive manufacturing (AM) or solid freeform fabrication (SFF) technique is extensively used to produce intrinsic 3D structures with high accuracy. Its significant contributions in the field of tissue engineering (TE) have significantly increased in the recent years. TE is used to regenerate or repair impaired tissues which are caused by trauma, disease and injury in human body. There are a number of novel materials such as polymers, ceramics and composites, which possess immense potential for production of scaffolds. However, the major challenge is in developing those bioactive and patient-specific scaffolds, which have a required controlled design like pore architecture with good interconnectivity, optimized porosity and microstructure. Such design not only supports cell proliferation but also promotes good adhesion and differentiation. However, the traditional techniques fail to fulfill all the required specific properties in tissue scaffold. The purpose of this study is to report the review on AM techniques for the fabrication of TE scaffolds.
Design/methodology/approach
The present review paper provides a detailed analysis of the widely used AM techniques to construct tissue scaffolds using stereolithography (SLA), selective laser sintering (SLS), fused deposition modeling (FDM), binder jetting (BJ) and advanced or hybrid additive manufacturing methods.
Findings
Subsequently, this study also focuses on understanding the concepts of TE scaffolds and their characteristics, working principle of scaffolds fabrication process. Besides this, mechanical properties, characteristics of microstructure, in vitro and in vivo analysis of the fabricated scaffolds have also been discussed in detail.
Originality/value
The review paper highlights the way forward in the area of additive manufacturing applications in TE field by following a systematic review methodology.
Details
Keywords
Kesheng Lin, Jie Liu, Jia-Min Wu, Yunlong Sun, Feng Li, Yan Zhou and Yusheng Shi
The main cause of aseptic inflammation after an in vivo implantation is that Poly(L-lactide) (PLLA) and Poly(D-lactide) have a slower degradation and absorption rate, while…
Abstract
Purpose
The main cause of aseptic inflammation after an in vivo implantation is that Poly(L-lactide) (PLLA) and Poly(D-lactide) have a slower degradation and absorption rate, while Poly(D, L-lactide) (PDLLA) has a much faster degradation rate than PLLA because of its amorphous structure. Also, the hydrolyzate of Hydroxyapatite (HA) is alkaline, which can neutralize local tissue peracid caused by hydrolysis of Polylactic acid.
Design/methodology/approach
In this study, the selective laser sintering (SLS) technique was chosen to prepare bone scaffolds using nano-HA/PDLLA composite microspheres, which were prepared by the solid-in-oil-in-water (S/O/W) method. First, the SLS parameters range of bulk was determined by the result of a single-layer experiment and the optimized parameters were then obtained by the orthogonal experiment. The tensile property, hydrophobicity, biocompatibility, biological toxicity and in vitro degradation of the samples with optimized SLS parameters were characterized.
Findings
As a result, the samples showed a lower tensile strength because of the many holes in their interior, which was conducive to better cell adhesion and nutrient transport. In addition, the samples retained their inherent properties after SLS and the hydrophobicity was improved after adding nano-HA because of the OH group. Furthermore, the samples showed good biocompatibility with the large number of cells adhering to the material through pseudopods and there was no significant difference between the pure PDLLA and 10% HA/PDLLA in terms of biological toxicity. Finally, the degradation rate of the composites could be tailored by the amount of nano-HA.
Originality/value
This study combined the S/O/W and SLS technique and provides a theoretical future basis for the preparation of drug-loaded microsphere scaffolds through SLS using HA/PDLLA composites.
Details
Keywords
Thermal insulation is important to achieve energy efficiency in a buildings’ lifespan while maintaining comfort. Traditionally, the majority of insulation in buildings is man-made…
Abstract
Purpose
Thermal insulation is important to achieve energy efficiency in a buildings’ lifespan while maintaining comfort. Traditionally, the majority of insulation in buildings is man-made petroleum based products with limited or no-end life usage. However, from an environmental and economic sustainability perspective, they are not sustainable as natural resources are finite and in danger of run-out. Furthermore, they are also highly influenced by the increasing price and the ongoing scarcity of fossil fuel oils. The paper aims to discuss these issues.
Design/methodology/approach
This paper introduces soap based insulation from recycled materials as a sustainable alternative to petroleum counterparts. The methodology is lab based experimentation and iterative tests. The phased based research process for the incremental development of the soap based thermal insulation is explained.
Findings
Findings reveal that soap based insulation can be one possible way forward in the quest for natural and sustainable thermal insulation from recycled products to preserve and conserve the sustainable environment.
Originality/value
Thus, the paper provides a unique environmentally friendly approach as an alternative to those existing petroleum counterparts for thermal insulation in buildings.
Details
Keywords
Mohammadreza Lalegani Dezaki, Mohd Khairol Anuar Mohd Ariffin and Saghi Hatami
The purpose of this paper is to review research studies on process optimisation and machine development that lead to the enhancement of final products in various aspects of the…
Abstract
Purpose
The purpose of this paper is to review research studies on process optimisation and machine development that lead to the enhancement of final products in various aspects of the fused deposition modelling (FDM) process.
Design/methodology/approach
An overview of the literature, focussing on process parameters, machine developments and material characterisations. This study investigates recent research studies that studied FDM capabilities in printing a vast range of materials from thermoplastics to metal alloys.
Findings
FDM is one of the most common techniques in additive manufacturing (AM) processes. Many parameters in this technology have effects on three-dimensional printed products. Therefore, it is necessary to obtain the optimum elements, for example, build orientation, layer thickness, nozzle diameter, infill pattern and bed temperature. By selecting a proper variable range of parameters, the layers adhere strongly and building end-use products of high quality are achievable. A vast range of materials and their properties from polymers to composite-based polymers are presented. Novel techniques to print metal alloys and composites are examined to increase the productivity of the FDM process. Additionally, defects such as shrinkage and warpage are discussed to eliminate the system’s limitations and improve the quality of final products. Multi-axis and mobile machines brought enhancements throughout the process to eliminate obstacles such as staircase defects in the conventional FDM process. In brief, recent developments were identified and a summary of major improvements was discussed in this study for future research.
Originality/value
This paper is an overview that provides information about research and developments in FDM. This review focusses on process optimisation and obstacles in printing polymers, composites, geopolymers and novel materials. Therefore, machine characteristics were examined to find out the accessibility of printing novel materials for different applications.
Details
Keywords
The Akzo Chemicals stand will display its full range of chemicals for coatings applications.
The paint industry is always intrigued by speciality coatings. Literally thousands of paint formulations have been devised over the years with highly specialized and very…
Abstract
The paint industry is always intrigued by speciality coatings. Literally thousands of paint formulations have been devised over the years with highly specialized and very frequently intriguing functions. In this latter category is a process described in Japanese patent 19,790 (1971) for painting polka dots upon sheet metal. How often the need for such technology might arise in the life of the average paint chemist is, of course, a moot question. But some comfort can no doubt be drawn from the fact that this unique methodology exists!