To investigate the possibility of using bamboo-bundle laminated veneer lumber (BLVL) as a cooling tower packing material, the water absorption rates, thickness swelling rates, and flexural properties of three different composite materials were studied. The BLVL was combined with either 12% or 24% phenol formaldehyde resin (PF), and the moso bamboo strips were exposed to water baths at three dif...

Thermo-sensitive hydrogels were prepared by graft copolymerization of Polyvenylalcohol and chitosan with N-Isopropylacrylamide via gamma radiation. Characterization of hydrogels such as DSC analysis and swelling and solubility tests in different ratios were investigated. DSC and solubility analysis showed chitosan and PVA and NIPAAm monomer were grafted via gamma radiation successfully. Results...

In this work, we compare the properties of smart homopolymer microgels based on N-n-propylacrylamide (NNPAM), N-isopropylacrylamide (NIPAM) and N-isopropylmethacrylamide (NIPMAM) synthesized under identical conditions. The particles are studied with respect to size, morphology, and swelling behavior using scanning electron and scanning force microscopy. In addition, light scattering techniques ...

N-isopropylacrylamide (NIPAAM)/maleic acid (MA) copolymeric hydrogels were prepared by irradiating the ternary mixtures of NIPAAM/MA/Water by g-rays at ambient temperature. The influence of external stimuli such as pH and temperature of the swelling media on the equilibrium swelling properties was investigated. The hydrogels showed both temperature and pH responses. The effect of comonomer conc...

Abstract. We develop a general theory of the swelling kinetics of polymer gels, with the view that a polymer gel is a two-phase fluid. The model we propose is a free boundary problem and can be used to understand both contraction and swelling, including complete dissolving or dehydration of polymeric gels. We show that the equations of motion satisfy a minimum energy dissipation rate principle ...

The subject of this study is the modeling of the evolution of the swelling pressure of granulates with cohesive-frictional, rough and elasto-plastic “microscopic” contact properties. The spherical particles are randomly arranged in a periodic cubic space with a fixed volume so that an increase of the particle size – i.e. swelling that can be caused by intake of some fluid – is accompanied by a ...

It is well-known that the swelling behavior of ionic nanogels depends on their cross-link density; however, it is unclear how different topologies should affect the response of the polyelectrolyte network. Here we perform Monte Carlo simulations to obtain the equilibrium properties of ionic nanogels as a function of salt concentration Cs and the fraction f of ionizable groups in a polyelectroly...

Biological tissues like intervertebral discs and articular cartilage primarily consist of interstitial fluid, collagen fibrils and negatively charged proteoglycans. Due to the fixed charges of the proteoglycans, the total ion concentration inside the tissue is higher than in the surrounding synovial fluid (cation concentration is higher and the anion concentration is lower). This excess of ion ...

The current breed of natural-fiber based polymer composites, because of their biobased and possibly biodegradable nature, offer an alternative as a ‘green’ material available for automotive and other engineering applications. However such composites suffer from the drawback of low strength and fatigue properties compared to the carbonor glass-fiber based polymer composites. Cellulose nanofibers...

The swelling properties and thermal transition of hydrogels can be tailored by changing the hydrophilic-hydrophobic balance of polymer networks. Especially, poly(N-isopropylacrylamide) (PNIPAm) has received attention as thermo-responsive hydrogels for tissue engineering because its hydrophobicity and swelling property are transited around body temperature (32 °C). In this study, we investigated...