Starch and its derivatives have recently emerged as a sustainable and renewable alternative for p... more Starch and its derivatives have recently emerged as a sustainable and renewable alternative for petroleum-based expanded polystyrene (EPS) and expanded polypropylene (EPP) foam materials. In this study, biodegradable foam materials were prepared from cassava starch using a novel dual modification technique, combining microwave treatment and freeze-drying. The foam materials were prepared from starch solutions microwaved over different intervals. The starch-based foam materials were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), 13C nuclear magnetic resonance (13C-NMR) spectroscopy, and compression set test. Moreover, the water absorption capacities and density values of the foam materials were measured according to ASTM standards. The biodegradability test was carried out according to the aerobic compost environment test. The lowest water absorption capacities of 65.56% and 70.83% were exhibited for the cassava starch foam sample (MWB) prepared at a 20 s microwave treatment time and immersed in distilled water for 2 and 24 h, respectively. Furthermore, the lightweight cassava starch-based foam materials displayed density ranging from 124 to 245 kg/m3. The biodegradation test exhibited significant biodegradation of over 50% after 15 days for all the foam materials prepared. These results suggest that the dual-modified cassava starch-based biodegradable foams show potential in sustainable packaging applications by replacing petroleum-based materials.
Starch is a renewable resource and starch films play a vital role as an alternative for synthetic... more Starch is a renewable resource and starch films play a vital role as an alternative for synthetic polymers in packaging applications. However, the films prepared from native starch fail to meet the process or product requirements due to high water absorption and inferior mechanical properties. In order to avoid these drawbacks, and to enhance the desired properties, starch can be modified using acid hydrolysis. In this study, the effects of acid hydrolysis time on the structural, thermal, and chemical properties of cassava starch and cassava starch thin films were investigated. Native cassava starch was hydrolyzed using 2.2 M hydrochloric acid with varying time intervals. With the increase of hydrolysis time, the relative crystallinity of cassava starch increased while the thermal decomposition temperature decreased in cassava starch. XRD and 13C-NMR spectrums results show that, cassava starch has been subjected to polymorphism changes from A (monoclinic cell) to B (hexagonal unit c...
The health and environmental concerns of the usage of non-biodegradable plastics have driven effo... more The health and environmental concerns of the usage of non-biodegradable plastics have driven efforts to explore replacing them with renewable polymers. Although starch is a vital renewable polymer, poor water resistivity and thermo-mechanical properties have limited its applications. Recently, starch/synthetic biodegradable polymer blends have captured greater attention to replace inert plastic materials; the question of ‘immiscibility’ arises during the blend preparation due to the mixing of hydrophilic starch with hydrophobic polymers. The immiscibility issue between starch and synthetic polymers impacts the water absorption, thermo-mechanical properties, and chemical stability demanded by various engineering applications. Numerous studies have been carried out to eliminate the immiscibility issues of the different components in the polymer blends while enhancing the thermo-mechanical properties. Incorporating compatibilizers into the blend mixtures has significantly reduced the p...
Airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) ... more Airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are significant contributors leading to many human health issues. Thus, this study was designed to perform chemical analysis and biological impact of airborne particulate matter 10 (PM10) in the World heritage City of Kandy City in Sri Lanka. 12 priority PAHs and 34 metals, including 10 highly toxic HMs were quantified. The biological effects of organic extracts were assayed using an in vitro primary porcine airway epithelial cell culture model. Cytotoxicity, DNA damage, and gene expressions of selected inflammatory and cancer-related genes were also assessed. Results showed that the total PAHs ranged from 3.062 to 36.887 ng/m3. The metals were dominated by Na > Ca > Mg > Al > K > Fe > Ti, while a few toxic HMs were much higher in the air than the existing ambient air quality standards. In the bioassays, a significant cytotoxicity (p < 0.05) was observed at 300 μg/mL treatment, and significant (p < 0.05) DNA damages were noted in all treatment groups. All genes assessed were found to be significantly up-regulated (p < 0.05) after 24 h of exposure and after 48 h, only TGF-β1 and p53 did not significantly up-regulate (p < 0.05). These findings confirm that the Kandy city air contains potential carcinogenic and mutagenic compounds and thus, exposure to Kandy air may increase the health risks and respiratory tract-related anomalies.
Solid waste (mis)management is one of the most serious local environmental problems in Sri Lanka ... more Solid waste (mis)management is one of the most serious local environmental problems in Sri Lanka (Figure 1). It has become a big threat to public health, the beautiful environment and a burden to the national economy
Abstract Decision making under uncertainty is vital in the early chemical process development. Co... more Abstract Decision making under uncertainty is vital in the early chemical process development. Competing objectives such as SHE and economics are considered in a data-lean environment. Screening of potential synthetic route options is done in a team environment with experts from different disciplines such as chemists and chemical engineers. Simple ranking methods are used and those hardly reveal the rationale behind choices. A systematic framework to support better decisions based on the SELECT (Safety, Environment, Legal, Economics, Control, Throughput) criteria has been developed and demonstrated using Cephalosporin process development. This approach links three components namely uncertainty, risk and capability analyses for multi-objective decision making. Each area of the decision criteria is scored using a hierarchical data structure for comparing different options. This approach improves the decision maker's understanding on the rationale behind choices and records them explicitly for improved learning. Further development and limitations of the approach are also discussed.
Abstract Procedures for the preparation of methyl cellulose/montmorillonite (MC/MMT) nanocomposit... more Abstract Procedures for the preparation of methyl cellulose/montmorillonite (MC/MMT) nanocomposite films were optimized by testing 30 procedures including differences in type of mixing, speed of mixing and time of mixing. The characterization of films by XRD and TEM indicated that a procedure involving mixing by a homogenizator was the most suitable nanocomposite film preparation method. The effect of MMT concentration on some properties of MC/MMT nanocomposite films was also investigated. It was found that the increase in the MMT concentration caused an increase in the film thickness and opacity values of MC/MMT nanocomposite films, whereas the increase in MMT concentration led to a decrease in their water adsorption and water solubility.
Starch is one of the most common biodegradable polymers found in nature, and it is widely utilize... more Starch is one of the most common biodegradable polymers found in nature, and it is widely utilized in the food and beverage, bioplastic industry, paper industry, textile, and biofuel industries. Starch has received significant attention due to its environmental benignity, easy fabrication, relative abundance, non-toxicity, and biodegradability. However, native starch cannot be directly used due to its poor thermo-mechanical properties and higher water absorptivity. Therefore, native starch needs to be modified before its use. Major starch modification techniques include genetic, enzymatic, physical, and chemical. Among those, chemical modification techniques are widely employed in industries. This review presents comprehensive coverage of chemical starch modification techniques and genetic, enzymatic, and physical methods developed over the past few years. In addition, the current applications of chemically modified starch in the fields of packaging, adhesives, pharmaceuticals, agri...
In Sri Lanka wastewater originated from prawn-farms contain an excessive amount of nitrate that i... more In Sri Lanka wastewater originated from prawn-farms contain an excessive amount of nitrate that is becoming a crucial issue on human health and environment. Currently, there are no proper practices...
Pharmaceutical product development is typically started from medicinal chemistry route, which wil... more Pharmaceutical product development is typically started from medicinal chemistry route, which will be changed synthetically at least once to generate a commercially viable route. Therefore, synthetic route (SR) forms the basis for process development. There is an enormous pressure for process development teams to take right decisions at the right time due to their importance in the downstream of the product life cycle (e.g. process scale up and manufacturing, importance of reaching the market first, capitalising the market and getting the maximum benefit during the ramp-up period). Generally, safety, health and environment (SHE) are the main aspects considered in the chemical process development. However, there are number of other important factors (e.g. chemical feasibility, intellectual property issues, raw material availability, cost of goods, etc) needed to consider in the pharmaceutical process development. Different organisations use their own decision supporting and knowledge...
Starch and its derivatives have recently emerged as a sustainable and renewable alternative for p... more Starch and its derivatives have recently emerged as a sustainable and renewable alternative for petroleum-based expanded polystyrene (EPS) and expanded polypropylene (EPP) foam materials. In this study, biodegradable foam materials were prepared from cassava starch using a novel dual modification technique, combining microwave treatment and freeze-drying. The foam materials were prepared from starch solutions microwaved over different intervals. The starch-based foam materials were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), 13C nuclear magnetic resonance (13C-NMR) spectroscopy, and compression set test. Moreover, the water absorption capacities and density values of the foam materials were measured according to ASTM standards. The biodegradability test was carried out according to the aerobic compost environment test. The lowest water absorption capacities of 65.56% and 70.83% were exhibited for the cassava starch foam sample (MWB) prepared at a 20 s microwave treatment time and immersed in distilled water for 2 and 24 h, respectively. Furthermore, the lightweight cassava starch-based foam materials displayed density ranging from 124 to 245 kg/m3. The biodegradation test exhibited significant biodegradation of over 50% after 15 days for all the foam materials prepared. These results suggest that the dual-modified cassava starch-based biodegradable foams show potential in sustainable packaging applications by replacing petroleum-based materials.
Starch is a renewable resource and starch films play a vital role as an alternative for synthetic... more Starch is a renewable resource and starch films play a vital role as an alternative for synthetic polymers in packaging applications. However, the films prepared from native starch fail to meet the process or product requirements due to high water absorption and inferior mechanical properties. In order to avoid these drawbacks, and to enhance the desired properties, starch can be modified using acid hydrolysis. In this study, the effects of acid hydrolysis time on the structural, thermal, and chemical properties of cassava starch and cassava starch thin films were investigated. Native cassava starch was hydrolyzed using 2.2 M hydrochloric acid with varying time intervals. With the increase of hydrolysis time, the relative crystallinity of cassava starch increased while the thermal decomposition temperature decreased in cassava starch. XRD and 13C-NMR spectrums results show that, cassava starch has been subjected to polymorphism changes from A (monoclinic cell) to B (hexagonal unit c...
The health and environmental concerns of the usage of non-biodegradable plastics have driven effo... more The health and environmental concerns of the usage of non-biodegradable plastics have driven efforts to explore replacing them with renewable polymers. Although starch is a vital renewable polymer, poor water resistivity and thermo-mechanical properties have limited its applications. Recently, starch/synthetic biodegradable polymer blends have captured greater attention to replace inert plastic materials; the question of ‘immiscibility’ arises during the blend preparation due to the mixing of hydrophilic starch with hydrophobic polymers. The immiscibility issue between starch and synthetic polymers impacts the water absorption, thermo-mechanical properties, and chemical stability demanded by various engineering applications. Numerous studies have been carried out to eliminate the immiscibility issues of the different components in the polymer blends while enhancing the thermo-mechanical properties. Incorporating compatibilizers into the blend mixtures has significantly reduced the p...
Airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) ... more Airborne particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) are significant contributors leading to many human health issues. Thus, this study was designed to perform chemical analysis and biological impact of airborne particulate matter 10 (PM10) in the World heritage City of Kandy City in Sri Lanka. 12 priority PAHs and 34 metals, including 10 highly toxic HMs were quantified. The biological effects of organic extracts were assayed using an in vitro primary porcine airway epithelial cell culture model. Cytotoxicity, DNA damage, and gene expressions of selected inflammatory and cancer-related genes were also assessed. Results showed that the total PAHs ranged from 3.062 to 36.887 ng/m3. The metals were dominated by Na > Ca > Mg > Al > K > Fe > Ti, while a few toxic HMs were much higher in the air than the existing ambient air quality standards. In the bioassays, a significant cytotoxicity (p < 0.05) was observed at 300 μg/mL treatment, and significant (p < 0.05) DNA damages were noted in all treatment groups. All genes assessed were found to be significantly up-regulated (p < 0.05) after 24 h of exposure and after 48 h, only TGF-β1 and p53 did not significantly up-regulate (p < 0.05). These findings confirm that the Kandy city air contains potential carcinogenic and mutagenic compounds and thus, exposure to Kandy air may increase the health risks and respiratory tract-related anomalies.
Solid waste (mis)management is one of the most serious local environmental problems in Sri Lanka ... more Solid waste (mis)management is one of the most serious local environmental problems in Sri Lanka (Figure 1). It has become a big threat to public health, the beautiful environment and a burden to the national economy
Abstract Decision making under uncertainty is vital in the early chemical process development. Co... more Abstract Decision making under uncertainty is vital in the early chemical process development. Competing objectives such as SHE and economics are considered in a data-lean environment. Screening of potential synthetic route options is done in a team environment with experts from different disciplines such as chemists and chemical engineers. Simple ranking methods are used and those hardly reveal the rationale behind choices. A systematic framework to support better decisions based on the SELECT (Safety, Environment, Legal, Economics, Control, Throughput) criteria has been developed and demonstrated using Cephalosporin process development. This approach links three components namely uncertainty, risk and capability analyses for multi-objective decision making. Each area of the decision criteria is scored using a hierarchical data structure for comparing different options. This approach improves the decision maker's understanding on the rationale behind choices and records them explicitly for improved learning. Further development and limitations of the approach are also discussed.
Abstract Procedures for the preparation of methyl cellulose/montmorillonite (MC/MMT) nanocomposit... more Abstract Procedures for the preparation of methyl cellulose/montmorillonite (MC/MMT) nanocomposite films were optimized by testing 30 procedures including differences in type of mixing, speed of mixing and time of mixing. The characterization of films by XRD and TEM indicated that a procedure involving mixing by a homogenizator was the most suitable nanocomposite film preparation method. The effect of MMT concentration on some properties of MC/MMT nanocomposite films was also investigated. It was found that the increase in the MMT concentration caused an increase in the film thickness and opacity values of MC/MMT nanocomposite films, whereas the increase in MMT concentration led to a decrease in their water adsorption and water solubility.
Starch is one of the most common biodegradable polymers found in nature, and it is widely utilize... more Starch is one of the most common biodegradable polymers found in nature, and it is widely utilized in the food and beverage, bioplastic industry, paper industry, textile, and biofuel industries. Starch has received significant attention due to its environmental benignity, easy fabrication, relative abundance, non-toxicity, and biodegradability. However, native starch cannot be directly used due to its poor thermo-mechanical properties and higher water absorptivity. Therefore, native starch needs to be modified before its use. Major starch modification techniques include genetic, enzymatic, physical, and chemical. Among those, chemical modification techniques are widely employed in industries. This review presents comprehensive coverage of chemical starch modification techniques and genetic, enzymatic, and physical methods developed over the past few years. In addition, the current applications of chemically modified starch in the fields of packaging, adhesives, pharmaceuticals, agri...
In Sri Lanka wastewater originated from prawn-farms contain an excessive amount of nitrate that i... more In Sri Lanka wastewater originated from prawn-farms contain an excessive amount of nitrate that is becoming a crucial issue on human health and environment. Currently, there are no proper practices...
Pharmaceutical product development is typically started from medicinal chemistry route, which wil... more Pharmaceutical product development is typically started from medicinal chemistry route, which will be changed synthetically at least once to generate a commercially viable route. Therefore, synthetic route (SR) forms the basis for process development. There is an enormous pressure for process development teams to take right decisions at the right time due to their importance in the downstream of the product life cycle (e.g. process scale up and manufacturing, importance of reaching the market first, capitalising the market and getting the maximum benefit during the ramp-up period). Generally, safety, health and environment (SHE) are the main aspects considered in the chemical process development. However, there are number of other important factors (e.g. chemical feasibility, intellectual property issues, raw material availability, cost of goods, etc) needed to consider in the pharmaceutical process development. Different organisations use their own decision supporting and knowledge...
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