Preface

**Section 3 Acrylate Mitigation in Foods and Water 149**

Chapter 7 **Mitigation of Acrylamide in Foods: An African**

Chapter 8 **The Use of Acrylic-Based Polymers in Environmental**

**Remediation Studies 175** Aslı Erdem Yayayürük

Oluwafemi Ayodeji Adebo, Eugenie Kayitesi, Janet Adeyinka Adebiyi, Sefater Gbashi, Makumba Chewe Temba, Adeseye Lasekan, Judith Zanele Phoku and Patrick Berka Njobeh

**Perspective 151**

**VI** Contents

Polymer chemistry occupied a central position among the sciences, having a close associa‐ tion with physics via the concepts and principles of physical chemistry and with biology through its application to biological aspects. The chemical technology, especially the branch of acrylic polymers in polymer chemistry and technology, has contributed fundamentally towards the development of healthcare in recent times. The development and the applica‐ tion of acrylic polymers towards dentistry and drug delivery systems are dependent on the chemistry to provide explanations necessary for their development.

The combination of polymer composition, chain length, branching, cross-linking and molec‐ ular orientation can produce a variety of requisite properties. Towards the needs of various dental applications and drug delivery systems, these features are manipulated to produce a balance of optimum properties that approach the ideal performance properties as closely as is practical. The properties are grouped into four interrelated categories, namely, mechani‐ cal, thermal, rheological (flow) and dissolution in a relevant medium. The applied forces produce stresses within polymers for prosthetics and drug delivery applications that cause materials to deform (undergo strain) via either elastic or plastic or a combination of elastic and plastic strain (viscoelastic strain).

The other major contributing factor is cross-linking by using materials having hydro-/lipo‐ philic units. In the absence of cross-linking, only relative weak inter-polymer-chain bonds (van der Waals and hydrogen bonds) are available to hold the polymer chains together in a solid state. The chain slippage decreases as the chain length increases because the bonds be‐ tween chains, together with chain entanglements, resist dislodgement of the individual chains. At a definite chain length, the resistance provided by the inter-chain bonds and en‐ tanglements becomes strong enough to exceed the covalent strength of the C–C bonds along the backbone chains. At this critical chain length, an applied force can rupture chains rather than dislodge them and cause one chain to slide past another. The balance between the strengths of the interaction bonds and the covalent bonds along the backbone chains ex‐ plains why the physical and mechanical properties of polymers increase with increased mo‐ lecular weight up to a certain point.

This book presents eight chapters organised under three parts vividly by providing a wealth of new ideas in design, synthesis and a detailed study of new acrylate materials in health‐ care applications. Most chapters are introduced with some relevant features. This helps to focus attention on some of the more important details and provides a framework upon which learning and understanding can be built. These also help to identify specific points that researchers frequently attempt to incorporate when conducting an advanced research.

Part I represents Chapters 1, 2, 3 and 4. Chapter 1 deals with acrylates and their alternatives in dental applications. Here, three aspects were covered, namely, mechanical properties (frac‐ ture behaviour, water absorption and mechanical strength degradation) caused by the expo‐ sure to saliva of classical heat-cured acrylic resins, studies concerning biocompatibility (in vivo and in vitro tests) of acrylic resins and alternative resins and technologies for denture manufacturing. Chapter 2 describes about the acrylates in dental applications. Here, the role played by acrylates in dentistry has been highlighted. The composition, functions and types of teeth have been described. The materials including dentures, adhesives, impression trays and dental crowns are used widely in dentistry and dental prosthetics in the preparation of which the key role is played by acrylates have been characterised. Special attention has been drawn on the possibility of modification of the synthesis of acrylic materials that can lead to the im‐ provement of their properties and result in making them more favourable from the point of view of the patient. Chapter 3 represents some new trends for the processing of poly(methyl methacrylate) (PMMA) biomaterial used for dental prosthodontics. The main aspects covered here are the artefacts of synthesis, morphology and the biological properties, namely, cytotox‐ icity, mutagenicity, biocompatibility and the anti-microbiological activity of PMMA. Chapter 4 carried out the latest improvements of acrylic-based polymer properties for biomedical ap‐ plications. The acrylics have been fabricated as multicomponent polymeric systems in the form of interpenetrated polymer networks or combined with other advanced materials such as fibres, nanofibres, graphene and its derivatives and/or many other kinds of nanoparticles (NPs) to form composite or nanocomposite materials, which are expected to exhibit superior properties. Besides, in regenerative medicine, acrylic scaffolds are designed with the required extent, and morphology of pores is characterised by sophisticated techniques.

Part II comprises Chapters 5 and 6. In Chapter 5, synthetic polymer-based nanoparticles as intelligent drug delivery systems are described. This chapter aims to look at the 'hot spots' in the design of synthetic polymer nanoparticles as an intelligent drug delivery system in terms of biopharmaceutical challenges and in relation to the route of their administration, namely, the non-invasive—oral, transdermal, transmucosal (nasal, buccal/sublingual, vagi‐ nal, rectal and ocular) and inhalation routes—and the invasive parenteral route. Chapter 6 presents spectroscopic investigations of poly(vinyl alcohol) film with complex of terbium ions along with bismuth nanoparticles for improved green emission. The bismuth nanopar‐ ticles (NPs) have been synthesised by the pulsed laser ablation technique at different pH in different aqueous solutions [viz. water (H), water + sodium hydroxide (HN) and water + hydrochloric acid (HC)]. The NPs in aqueous solutions have been characterised by TEM and UV-Vis-NIR absorption techniques. Then, photoluminescence properties of Tb3+ ions and the [Tb(Sal)3(Phen)] complex were studied using 266 nm and 355 nm as excitation wavelengths to seek into the influence of Bi NPs on their emissive properties.

Part III deals with Chapters 7 and 8. Chapter 7 investigates mitigation of acrylamide (ACR) in foods in the context of an African perspective. Acrylamide (ACR) is a possible human carcinogen, with neurotoxic properties. It is a heat-generated food toxicant particularly found in carbohydrate-rich foods. However, information on the extent of ACR occurrence in foods consumed in different parts of Africa is rather too limited. This covers the formation, occurrence and health impact of ACR in foods. It further summarises previous studies look‐ ing at ACR reduction and mitigation strategies, especially those that may be applicable in the African continent. Chapter 8 presents the use of acrylic-based polymers in environmen‐ tal remediation studies. The polymeric adsorbents have received considerable interest for heavy metal removal mainly due to important technological and scientific developments such as easy synthesis at controlled dimensions with variable functional groups, perfect me‐ chanical rigidity, tunable surface chemistry, large surface area, pore size distribution, high uptake values and feasible regeneration under mild conditions. Also, an attempt to present to the readers the widespread investigations of acrylic-based polymeric adsorbents is made so that they can get an idea about the various types and forms of polymeric materials used for the removal of heavy metals from water.

Part I represents Chapters 1, 2, 3 and 4. Chapter 1 deals with acrylates and their alternatives in dental applications. Here, three aspects were covered, namely, mechanical properties (frac‐ ture behaviour, water absorption and mechanical strength degradation) caused by the expo‐ sure to saliva of classical heat-cured acrylic resins, studies concerning biocompatibility (in vivo and in vitro tests) of acrylic resins and alternative resins and technologies for denture manufacturing. Chapter 2 describes about the acrylates in dental applications. Here, the role played by acrylates in dentistry has been highlighted. The composition, functions and types of teeth have been described. The materials including dentures, adhesives, impression trays and dental crowns are used widely in dentistry and dental prosthetics in the preparation of which the key role is played by acrylates have been characterised. Special attention has been drawn on the possibility of modification of the synthesis of acrylic materials that can lead to the im‐ provement of their properties and result in making them more favourable from the point of view of the patient. Chapter 3 represents some new trends for the processing of poly(methyl methacrylate) (PMMA) biomaterial used for dental prosthodontics. The main aspects covered here are the artefacts of synthesis, morphology and the biological properties, namely, cytotox‐ icity, mutagenicity, biocompatibility and the anti-microbiological activity of PMMA. Chapter 4 carried out the latest improvements of acrylic-based polymer properties for biomedical ap‐ plications. The acrylics have been fabricated as multicomponent polymeric systems in the form of interpenetrated polymer networks or combined with other advanced materials such as fibres, nanofibres, graphene and its derivatives and/or many other kinds of nanoparticles (NPs) to form composite or nanocomposite materials, which are expected to exhibit superior properties. Besides, in regenerative medicine, acrylic scaffolds are designed with the required

VIII Preface

extent, and morphology of pores is characterised by sophisticated techniques.

to seek into the influence of Bi NPs on their emissive properties.

Part II comprises Chapters 5 and 6. In Chapter 5, synthetic polymer-based nanoparticles as intelligent drug delivery systems are described. This chapter aims to look at the 'hot spots' in the design of synthetic polymer nanoparticles as an intelligent drug delivery system in terms of biopharmaceutical challenges and in relation to the route of their administration, namely, the non-invasive—oral, transdermal, transmucosal (nasal, buccal/sublingual, vagi‐ nal, rectal and ocular) and inhalation routes—and the invasive parenteral route. Chapter 6 presents spectroscopic investigations of poly(vinyl alcohol) film with complex of terbium ions along with bismuth nanoparticles for improved green emission. The bismuth nanopar‐ ticles (NPs) have been synthesised by the pulsed laser ablation technique at different pH in different aqueous solutions [viz. water (H), water + sodium hydroxide (HN) and water + hydrochloric acid (HC)]. The NPs in aqueous solutions have been characterised by TEM and UV-Vis-NIR absorption techniques. Then, photoluminescence properties of Tb3+ ions and the [Tb(Sal)3(Phen)] complex were studied using 266 nm and 355 nm as excitation wavelengths

Part III deals with Chapters 7 and 8. Chapter 7 investigates mitigation of acrylamide (ACR) in foods in the context of an African perspective. Acrylamide (ACR) is a possible human carcinogen, with neurotoxic properties. It is a heat-generated food toxicant particularly found in carbohydrate-rich foods. However, information on the extent of ACR occurrence in foods consumed in different parts of Africa is rather too limited. This covers the formation, occurrence and health impact of ACR in foods. It further summarises previous studies look‐ ing at ACR reduction and mitigation strategies, especially those that may be applicable in the African continent. Chapter 8 presents the use of acrylic-based polymers in environmen‐ tal remediation studies. The polymeric adsorbents have received considerable interest for

#### **Dr. Boreddy S.R. Reddy**

D.Sc., Ph.D., C.Chem., FRSC (London), Scientist Emeritus and Director Grade Scientist (Formerly), Hertfordshire, England, United Kingdom
