Browsing by Author "Kosasih, BY"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    The effect of molecular structure on the adsorption of PPO-PEO-PPO triblock copolymers on solid surfaces
    (Trans Tech Publications, 2012-09-23) Lin, BJ; Zhu, HT; Tieu, AK; Kosasih, BY; Triani, G
    This paper investigates the adsorption behavior of triblock copolymer Poly (propylene oxide)-poly (ethylene oxide)-poly (propylene oxide), PPO-PEO-PPO on silicon and iron surfaces by using the contact angle goniometer, spectroscopic ellipsometer and atomic force microscopy (AFM). After adsorption, the decrease of water contact angle was observed on each surface; and a larger reduction of water contact angle occurred on the surface covered by the copolymer film with longer and higher weight percent of hydrophilic PEO block. This means that the PEO block may be on the top of the adsorbed copolymer film. The film thickness measurement shows that the copolymer with longer and higher weight percent of PPO block forms a thicker film on the hydrophobic surface, which suggests that the hydrophobic PPO block of the copolymer in the aqueous solution plays the main role during the adsorption of PPO-PEO-PPO onto the hydrophobic surface. It has been found from the AFM results that the roughness of the surface decreased after adsorption and the smoother topography was observed on the surface adsorbed by a thicker adsorbed film. © 2023 Trans Tech Publications
  • No Thumbnail Available
    Item
    Tribological performance of aqueous copolymer lubricant in loaded contact with Si and coated Ti film
    (Elsevier, 2013-04-01) Lin, BJ; Tieu, AK; Zhu, HT; Kosasih, BY; Novareza, O; Triani, G
    This paper concentrates on the tribological performance of the polymer aqueous solution poly(propylene oxide)–poly(ethylene oxide)–poly(propylene oxide), PPO–PEO–PPO. The adsorption process on the metal surface is significantly influenced by the concentration and structure of copolymer, and interaction between the copolymer/substrate. Experiments have been carried out to investigate the tribological properties of this copolymer, such as adsorbed thin film thickness and friction on silicon and titanium surfaces. The thickness of the adsorbed copolymer films were measured by Ellipsometry, and the tribological properties such as friction were investigated with a Pin-on-Disk tribometer. The results show that the triblock copolymer with a longer length PPO chain forms a thicker film of lubricant on the hydrophobic surfaces. It has been found from the Pin-on-Disk tribo-tests that the concentration of copolymer and ratio of the PPO and PEO blocks of aqueous polymer fluid can affect the coefficient of friction (COF). © 2013, Elsevier B.V.