Spectroscopy is the study of matter interacting with electromagnetic radiation (e.g., light). The electromagnetic spectrum in Figure 1 illustrates the many different types of electromagnetic radiation, including gamma rays (γ-rays), X-rays, ultraviolet (UV) radiation, visible light, infrared (IR) radiation, microwaves, and radio waves. The frequency (ν) and wavelength (λ) ranges associated with each form of radiant energy are also indicated in Figure 1.

Introduction to Spectroscopy

Bamboo fibre reinforced natural rubber composites were prepared by incorporation of different loadings of bamboo fibre. Two series of composites were studied i.e. composites with and without the presence of a bonding agent. The curing characteristics of the composites were determined and the composites were vulcanized at 150°C using a hot press. The properties of the composites such as tensile strength, tensile modulus, tear strength, elongation at break and hardness were studied. The adhesion between the bamboo fibre and the natural rubber were enhanced by the addition of bonding agent as exhibited by the tensile fracture surfaces of the composites using scanning electron microscopy (SEM). The presence of bonding agent also gave shorter curing time and enhanced mechanical properties.  2001 Elsevier Science Ltd. All rights reserved.

Material Properties Bamboo fibre filled natural rubber composites: the effects of filler loading and bonding agent

Recently, large quantities of oily wastewater discharged from our daily life and industries have caused serious environmental problems. In addition, frequent oil spill accidents occurred all over the world have also lead to a waste of precious resources. Oil/water separation has become a worldwide challenge for us to overcome. Nowadays, superwetting materials have attracted considerable attention. Among them, porous materials with special wettability are more popular since this kind of materials is easy to fabricate, cost saving and time saving. Moreover, by combining the design of special wettability with the proper pore size, the porous materials could achieve the separation of sundry oil/water mixtures including immiscible oil/water mixtures and stabilized emulsions. In this review, we summarized two types of superwetting porous materials for immiscible oil/water mixtures separation and emulsion separation: water blocking porous materials with superhydrophobic/superoleophilic wettability and oil blocking porous materials with superhydrophilic/underwater superoleophobic wettability. In each type, we introduce the mechanism, fabricating process, effects of oily wastewater treatment and the representative works in detail. Moreover, the smart controllable superwetting porous materials and the wastewater treatment of other pollutants are also introduced briefly.

Superwetting Porous Materials for Wastewater Treatment: from Immiscible Oil/Water Mixture to Emulsion Separation

Recent advancements in material technologies have promoted the development of various preparation strategies and applications of novel polymer–nanoclay composites. Innovative synthesis pathways have resulted in novel polymer–nanoclay composites with improved properties, which have been successfully incorporated in diverse fields such as aerospace, automobile, construction, petroleum, biomedical and wastewater treatment. These composites are recognized as promising advanced materials due to their superior properties, such as enhanced density, strength, relatively large surface areas, high elastic modulus, flame retardancy, and thermomechanical/optoelectronic/magnetic properties. The primary focus of this review is to deliver an up-to-date overview of polymer–nanoclay composites along with their synthesis routes and applications. The discussion highlights potential future directions for this emerging field of research.

A Review of the Synthesis and Applications of Polymer–Nanoclay Composites

Starch has received much attention as a promising natural material both in biomedical fields and waste water treatment due to its unique biological and adsorptive properties. Recently, the modification of starch is rapidly developed along with its growing applications. This review focuses on the ways of chemical modification of starch including cross-linking, grafting, esterification, etherification, dual modification and so on, and presents the applications of the modified starch in fields like drug delivery, tissue engineering and heavy metal and dye removal.

Recent progress in chemical modification of starch and its applications

In this study, redox-initiated free radical graft copolymerization of microcrystalline cellulose (MCC) and methyl methacrylate (MMA) has been carried out in aqueous media to develop a novel cellulose-based copolymer. Cerium ammonium nitrate was used as the initiator in the presence of nitric acid. Effects of monomer concentration, initiator concentration, polymerization time, and polymerization temperature on the graft parameters of copolymers were studied. The successful grafting copolymerization between MCC and MMA was validated through attenuated total reflection, wide-angle X-ray diffraction, field-emission scanning electron microscopy, and thermal gravimetric analysis. In comparison to native MCC, the resultant copolymers exhibited enhanced thermal stability and better compatibility with natural rubber, suggesting its potential application as reinforcement material in rubber industry. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42666.

Synthesis and characterization of microcrystalline cellulose‐graft‐poly(methyl methacrylate) copolymers and their application as rubber reinforcements

Mechanical, thermal and friction properties of rice bran carbon/nitrile rubber composites: Influence of particle size and loading

Graft copolymerization of methyl methacrylate (MMA) onto the corn starch (CS) backbone was carried out in an aqueous medium using ceric ammonium nitrate as an initiator under nitrogen atmosphere. The weight ratio of CS/MMA varied with their composition, as 7/3, 6/4, 5/5, 4/6, and 3/7 were used in this study of the graft efficiency and graft percentage (GP); thus, five different GP CS-g-PMMA copolymers were obtained. The molecular weight of CS-g-PMMA copolymers were measured by using gel permeation chromatography. The structure of CS and CS-g-PMMA copolymer were confirmed by infrared spectra. CS and CS-g-PMMA copolymers were characterized by thermal gravimetric analysis, differential scanning calorimetry, and scanning electron microscopy (SEM). Horowitz-Metzger and Broido methods were applied to investigate the thermal decomposition kinetics of CS-g-PMMA copolymers. The effect of GP on the activation energy of decomposition, crystallization behavior, and morphology was investigated. In addition, the biodegradability of CS-g-PMMA films were also studied by α-amylase treatment with different times. The weight loss of CS-g-PMMA films after α-amylase treatment were calculated. Finally, the morphology of CS-g-PMMA films before and after α-amylase treatment were observed by SEM photograph. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Synthesis, characterization, and enzymatic degradation of starch‐grafted poly(methyl methacrylate) copolymer films

Three types of modified starches (MST): Starch-g-poly(butyl acrylate) (ST-g-PBA), starch-g-poly (methyl methacrylate) (ST-g-PMMA) and starch-g-polystyrene (ST-g-PS) latexes were successfully synthesized by emulsion polymerization. These synthesized MST latexes were then directly compounded with styrene-butadiene rubber (SBR) latex in order to prepare MST/SBR compounds. The vulcanization characteristics, morphology, swelling ratio, mechanical and dynamic mechanical properties were investigated. Results indicated that the incorporation of starch or MST led to both an increase in the torque values and the cure rate of SBR compounds. MST with a particle size of approximately 200–400 nm uniformly dispersed in the SBR matrix, indicating the significantly improved dispersion. MST/SBR compounds exhibited better mechanical properties compared with starch/SBR (ST/SBR) compounds. Among the MST/SBR compounds, ST-g-PMMA/SBR compounds showed optimum tensile strength, which was even higher than that of carbon black/SBR (CB/SBR) compounds with the same loading of fillers. Finally, the reinforcing mechanism of MST in the SBR matrix was discussed.

Emulsion grafting vinyl monomers onto starch for reinforcement of styrene-butadiene rubber

Natural corn starch was modified by surface grafting with poly(methyl methacrylate) (PMMA) through emulsion copolymerization and then compounded with styrene-butadiene rubber (SBR) latex in order to prepare PMMA-modified starch/SBR biocomposites. The effect of methyl methacrylate (MMA) and starch concentration on the mechanical properties, morphology, toluene swelling behavior, water absorption behavior and biodegradabil- ity of PMMA-modified starch/SBR biocomposites was investigated. Results showed that the optimum mechanical properties were achieved when the concentrations of MMA and starch were 10 and 30 phr, respectively, which could be also confirmed through the observations from FE-SEM micrographs and equilibrium welling test. Guth-Gold and Halpin-Tsai models were employed to predict the modulus of PMMA-modified starch/SBR biocomposites. Halpin- Tsai model was better fitted with the experimentally measured data than Guth-Gold model. The water absorption ratio of PMMA-modified starch/SBR biocomposites was strongly influenced by the immersion time and the starch concentration, which further caused a significant effect on the biodegradability of biocomposites.

Ur Ryong Cho

Papers

Synthesis and characterization of microcrystalline cellulose‐graft‐poly(methyl methacrylate) copolymers and their application as rubber reinforcements

Mechanical, thermal and friction properties of rice bran carbon/nitrile rubber composites: Influence of particle size and loading

Synthesis, characterization, and enzymatic degradation of starch‐grafted poly(methyl methacrylate) copolymer films

Emulsion grafting vinyl monomers onto starch for reinforcement of styrene-butadiene rubber

Mechanical Performance, Water Absorption Behavior and Biodegradability of Poly(methyl methacrylate)-Modified Starch/SBR Biocomposites