Karnik Tarverdi

Karnik Tarverdi
Brunel University London · Chemical Engineering Department

About

41
Publications
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738
Citations

Publications

Publications (41)
Article
This study assessed the workability, mechanical, microstructural, and thermal behaviours of concrete composed from recycled waste polyethylene terephthalate (PET) as a partial or full replacement for natural coarse aggregates. Workability and Compressive/Split tensile strength tests alongside microstructural and thermogravimetric analysis were perf...
Article
Full-text available
Since curing remains an essential parameter that directly influences concrete strength and durability, this research aimed at evaluating the effects of water, sodium chloride (NaCl), and sodium carbonate (Na2CO3) curing regimes on concrete’s strength and durability. The design mix was composed of concrete mix ratio of 1:2:4, hydrated ordinary Portl...
Article
This study assesses the impacts of recycling waste polyethylene terephthalate (PET) plastic bottles as a partial substitute for fine natural aggregates on the workability, mechanical, microstructural, economic, and thermal properties of concrete. The mix design adopts a concrete mix ratio of 1:2:4 for grade M25, 0.55 water/cement ratio, ordinary Po...
Article
Offshore renewable energy can lead the way towards sustainable energy harvesting and support the achievement of the CO2 reduction target by 2030. To achieve this goal it is necessary to decrease the manufacturing and deployment cost of the offshore devices. This paper focusses on the mechanical, chemical and microstructural assessment of a novel hi...
Article
Methods of introducing and dispersing different phosphor particles into polymers using extrusion technology are reported. The extrusion and blending of phosphor/polymer combinations containing different percentages of phosphor and subsequent film blowing was studied. The phosphor/polymer films had their light emitting properties optimised to closel...
Article
The effects of poly(butylene adipate-co-terephthalate) (PBAT) on crystallization behavior and morphology of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were studied to provide the useful information to control and improve PHBV processing. PHBV were blended with 15, 30 and 50 wt% PBAT by twin screw extrusion and these were subsequently compa...
Article
The effects of calcium carbonate (CaCO3) concentration on crystallization behaviors and morphology of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were investigated. Composites of PHBV with CaCO3 were prepared with filler loadings of low (5%wt) and high concentration (20%wt) and these were subsequently compared to unloaded PHBV. The morpholo...
Article
The majority of disposable cups are made from paper plastic laminates (PPL) which consist of high quality cellulose fibre with a thin internal polyethylene coating. There are limited recycling options for PPLs and this has contributed to disposable cups becoming a high profile, problematic waste. In this work disposable cups have been shredded to f...
Patent
Full-text available
The invention according to the present invention relates to the manufacture of paper and or boards and/or binding agents and a method and apparatus related to the same by providing for the defibrillation of cellulose fibers into a form in which the same can be subsequently sued to form the finished product directly or can be used to bind other mate...
Article
The present paper reports work in development of biocomposite boards compression moulded from wheat straw. Unlike most traditional wood based fibre/chip boards with addition of adhesives or bonding agents, attempt was made to utilise the lignin-hemicellulosic natural resin within straw as bonding agent, resulting in a class of 'binderless' and more...
Article
Full-text available
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), a semi-polycrystalline biopolymer from the polyhydroxyalkanonate family has in recent years become a commercial bioplastic with mechanical properties comparable to isotactic polypropylene and enhanced O2, CO2 and H2O barrier properties. However, its brittleness and sensitivity to thermal and hydr...
Article
This paper reports work on extrusion foaming of poly(3-hydroxybutyrate-co- 3-hydroxyvalerate) with a chemical blowing agent based on sodium bicarbonate and citric acid and calcium carbonate nucleation agent. It includes investigations in the effects of rheological behaviour of the polymer, blowing agent, nucleation agent and processing conditions o...
Article
The effects of the use of a surfactant for the dispersion of the nanoparticles in a nano-clay/PET composite have been evaluated. An increase in the amount of surfactant improved the dispersion of the particles and consequently led to an enhancement of the mechanical properties of the nanocomposite. The composites were melt-blended using co-rotating...
Article
The majority of disposable cups are made from paper plastic laminates (PPL) which consist of high quality cellulose fibre with a thin internal polyethylene coating. There are limited recycling options for PPLs which has contributed to disposable cups becoming a high profile, problematic waste. In this work disposable cups have been shredded to form...
Conference Paper
Several different nanometre sized phosphors including iron doped lithium aluminate, LiAlO2:Fe, ZnO:Zn, and YAG:Ce have been synthesized and produced on an industrial scale. The excitation and emission characteristics of these phosphors, both as pure powders and embedded in polypropylene and other materials, are reported. The phosphors have applicat...
Article
Composites of poly (lactic acid) (PLA)/wheat starch and PLA/wheat starch/methyldiphenyldiisocyanate, were prepared and characterised in this study. The effects of incorporating different coupling agents on the physical properties and morphology of the composites were studied. Extrusion technology and injection moulding techniques were used to prepa...
Conference Paper
Iron doped lithium aluminate, LiAlO2:Fe, has been synthesized and produced on an industrial scale. The excitation and emission characteristics of this phosphor, both as a pure powder and embedded in polypropylene, are reported. The phosphor has applications for use as a UV degradation inhibitor when embedded in polymers.
Article
A study on structural and mechanical properties of natural fibres using co-rotating intermeshing twin screw extruder for refining fibres is reported. Using low-cost raw materials for the preparation of bio-based and biodegradable composites for many industrial applications. The natural fibres were pre-treated with dilute acids and alkali and fracti...
Article
Scitation is the online home of leading journals and conference proceedings from AIP Publishing and AIP Member Societies
Article
A study on structural and mechanical properties of bio-composites based on wheat straw and wheat flour is reported with a view to using these low-cost raw materials for the preparation of fully bio-based and biodegradable composites for non-structural applications. The wheat straw was pretreated with sodium hydroxide and fractionated in a twin scre...
Article
The present publication is concerning rheology characterisation and extrusion foaming of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with a chemical blowing agent based on sodium bicarbonate and citric acid. Also effect of calcium carbonate on foam morphology is investigated. PHBV is natural biodegradable polyester with high crystallinity....
Article
Full-text available
In this chapter we will explore the possibilities and viability of commercially recycling and reusing of composites and mixed polymer based waste that is difficult and expensive to separate into individual generic polymers for subsequent recycling. The chapter will also attempt to cover legislations that hinder and drive this technology and give up...
Article
This paper reports work in the extrusion fractionation of wheat straw and biocomposites utilising the entire constituents of straw. The effects of pre-treatment and extrusion conditions on fractionation of straw and mechanical properties of the biocomposites were studied systematically. It is demonstrated that twin screw extrusion can be used for e...
Article
The use of organoclay in polymers is expected to increase on average annually by about 5 percent. This paper describes melt blending techniques using PET nanocomposites containing commercially available organoclays with different percentage of surfactant coatings. This paper will also evaluate the morphology and mechanical properties of the composi...
Article
Mechanical recycling of waste polymeric based composites allows production of same or similar products, but in the case of vinyl wallpaper the quality of recovered material combines the cellulose component with the vinyl PVC resulting in a new composite which can have completely different applications compared with the original vinyl wallpaper. Vin...
Article
Established in 1987, the Wolfson Centre has been a focus for materials research in Brunel University. Since its inception, the research in the Centre has been based on the development of extrusion and injection-moulding technologies relating to polymer compound formulation, process-induced structuring, nano-composite processing and the processing o...
Article
Vinyl wallpaper has two principal materials of natural and synthetic origin used in its manufacture: Thermoplastic polymer (PVC) Polyvinyl chloride combined with cellulose fibre. The present paper will follow an interdisciplinary approach aimed at producing strategies for the recovery and reuse of these materials, thereby minimising the level of wa...
Article
The present paper discusses investigations into the manufacture, testing and application of a highly flexible structure incorporating innovative joints linked together to form a sheet that can be conformed around complex three-dimensional shapes which can be easily 'switched' from a flexible state to a highly stable/rigid one and a process which ca...
Article
The use of packaging materials is expected to increase annually on average by about 5 percent in the foreseeable future, but the technology for reusing and recycling of packaging waste is lagging behind. This paper considers the evaluation of an alternative packaging material, derived from renewable resources, which is economical to use, biodegrada...
Article
The microstructure, thermal and mechanical properties of a range of natural fibres, derived from arable crops, are examined with a view to using these as reinforcing additives for thermoplastics. The fibres were characterized prior to incorporation into the polymer using a range of techniques, including SEM, image analysis and thermogravimetric ana...
Article
The microstructure and mechanical properties of polypropylene composites containing flax and wheat straw fibres are discussed. Particular emphasis has been given to determining the nature and consequences of fibre damage induced during melt-processing operations, fibre orientation occurring in mouldings, and possible interfacial adhesion between th...
Article
Full-text available
The microstructure, thermal and mechanical properties of flax and wheat straw fibres have been examined with a view to using these natural fibres as reinforcing additives for thermoplastics. In this regard, the fibres were characterized prior to incorporation into the polymer, using a range of techniques, including SEM, image analysis, thermogravim...
Article
A novel twin screw extrusion compounding process is described for the preparation of polymer composites containing low cost reinforcing additives derived from waste products. The technology is exemplified using natural fibre reinforcements, from agricultural sources and fibre reinforced thermoset scrap, added to a polypropylene matrix. Central to t...
Article
The anionic polymerisation of ε-caprolactam in a corotating, intermeshing twin-screw extruder is discussed in terms of the materials formulation, extruder screw profile, and processing parameters such as temperature and screw speed. Using a variety of analytical characterization techniques, it is demonstrated that molecular mass, residual monomer c...

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