Magnetically Driven Chemomechanical Device with Poly(N-isopropylacrylamide) Hydrogel Containing γ-Fe2O3

Magnetic heating was applied to convert magnetic energy into chemomechanical work by using poly(N-isopropylacrylamide), poly(NIPAAm) gel, exhibiting a reversible swellingshrinking property. y-Fe2O3, which can generate heat by itself due to hysteresis loss in the presence of an alternating magnetic field, was immobilized within poly(NIPAAm) gel. The shrinking rate of the hydrogel accelerated when the inner temperature of the gel was increased over 34°C, the lower critical solution temperature (LCST). The initial rate of the temperature increase, which was in proportion to the amount of immobilized ferromagnetic powder, was 0.2°C/s in the gel immobilized 24% of the y-Fe2O3 weight under the alternating magnetic field (effective value 830 Oe, maximum value 1,170 Oe, 2.08 kHz). Cylindrical poly(NIPAAm) gel rods immobilized 24% y-Fe2O3, which was crosslinked by 5% N,N'-methylenebisacrylamide, were able to generate mechanical force. Five gel rods whose cross-area was 1.5 x 10-1 cm2 at 22°C could lift 20 g of weight up and down repeatedly by using contractile property of the gels. Shrinking of the gel rods was completed within 2 min. The hybrid poly(NIPAAm) gel containing the ferromagnetic powder could generate heat from inside and shrink spontaneously in the presence of the magnetic field. The magnetically driven chemomechanical device, which can convert magnetic energy into mechanical work, was studied using the hybrid hydrogel which was applied under the magnetic induction heating.

[1]  Makoto Suzuki,et al.  An approach to artificial muscle using polymer gels formed by micro-phase separation , 1993 .

[2]  Toyoichi Tanaka.  Collapse of Gels and the Critical Endpoint , 1978 .

[3]  Toyoichi Tanaka,et al.  Volume‐phase transitions of ionized N‐isopropylacrylamide gels , 1987 .

[4]  A S Hoffman,et al.  Immobilization of Arthrobacter simplex in a thermally reversible hydrogel: Effect of temperature cycling on steroid conversion , 1990, Biotechnology and bioengineering.

[5]  T. Park,et al.  Effect of temperature cycling on the activity and productivity of immobilized β-galactosidase in a thermally reversible hydrogel bead reactor , 1988, Applied biochemistry and biotechnology.

[6]  Fujio Takahashi,et al.  BOD sensor using magnetic activated sludge , 1995 .

[7]  Allan S. Huffman,et al.  Thermally reversible hydrogels: II. Delivery and selective removal of substances from aqueous solutions , 1986 .

[8]  F. Takahashi,et al.  Immobilized enzyme reaction controlled by magnetic heating : γ-Fe2O3-loaded thermosensitive polymer gels consisting of N-isopropylacrylamide and acrylamide , 1997 .

[9]  F. Takahashi,et al.  A submerged filter system consisting of magnetic tubular support media covered with a biofilm fixed by magnetic force , 1994 .

[10]  Yong Li,et al.  Kinetics of swelling and shrinking of gels , 1990 .

[11]  S. Gehrke,et al.  Synthesis of fast response, temperature-sensitive poly(N-isopropylacrylamide) gel , 1991 .

[12]  H. Ichijo,et al.  Preparation and mechanical properties of thermo-responsive fibrous hydrogels made from poly(vinyl methyl ether)s. , 1989 .

[13]  Toyoichi Tanaka,et al.  Volume phase transition in a nonionic gel , 1984 .

[14]  T. Park,et al.  Deswelling characteristics of poly(N-isopropylacrylamide) hydrogel , 1994 .

[15]  David Brock,et al.  A Dynamic Model of a Linear Actuator Based on Polymer Hydrogel , 1994 .

[16]  H. Ichijo,et al.  Thermo-Responsive Devices Using Poly(vinyl methyl ether) Hydrogels , 1993 .

[17]  S. Gehrke.  Synthesis, equilibrium swelling, kinetics, permeability and applications of environmentally responsive gels , 1993 .

[18]  Toyoichi Tanaka,et al.  Saccharide-sensitive phase transition of a lectin-loaded gel , 1991, Nature.

[19]  S. Gehrke,et al.  Effect of synthesis conditions on properties of poly(N‐isopropylacrylamide) gels , 1992 .

[20]  F. Takahashi,et al.  Preparation and Properties of Immobilized Glucoamylase on a Magnetically Anisotropic Carrier Comprising a Ferromagnetic Powder Coated by Albumin , 1992 .

[21]  Electro-driven chemomechanical polymer gel as an intelligent soft material. , 1994, Journal of biomaterials science. Polymer edition.

[22]  F. Takahashi,et al.  A sewage treatment process using highly condensed activated sludge with an apparatus for magnetic separation , 1994 .

[23]  F. Takahashi,et al.  Enhancement of ethanol formation by immobilized yeast containing iron powder or Ba-ferrite due to eddy current or hysteresis , 1994 .

[24]  F. Takahashi,et al.  Acceleration of Deswelling of Poly(N-isopropylacrylamide) Hydrogel by the Treatment of a Freeze-Dry and Hydration Process , 1997 .

[25]  F. Takahashi,et al.  Numerical Formulation of Pigment Release from Magnetically Anisotropic Gel Beads with Respect to the Magnetic Moment in an Alternating Magnetic Field , 1992 .

[27]  L. Dong,et al.  Controlled release of amylase from a thermal and pH-sensitive, macroporous hydrogel , 1992 .

[28]  Toyoichi Tanaka,et al.  Kinetics of swelling of gels , 1979 .

[29]  H. Unno,et al.  SWELLING PRESSURE OF POLY(VINYLMETHYLETHER) GEL (PVMEG) IN SWELLING PROCESS , 1988 .

[30]  Paul Yager,et al.  Synthesis and characterization of thermally reversible macroporous poly(N‐isopropylacrylamide) hydrogels , 1992 .

[31]  A Chemomechanical Polymer Gel with Electrically Driven Motility , 1993 .