Thermal deformation of imprinted twist nematic elastomers

نویسندگان

  • Isa Nishiyama
  • Akihisa Yokoyama
  • Jun Baek Park
  • Hyang Yul Kim
  • Kwi Hyun
  • Y Sawa
  • K Urayama
چکیده

A nematic elastomer film with a 90 o twist orientation between the top and bottom surfaces is prepared by chiral imprinting methods. The reactive achiral nematic monomers and crosslinkers are photopolymerized in the presence of a controlled amount of unreactive chiral dopant. The elastomer films possess a 90 o twist orientation even after the removal of the chiral dopant. The films exhibit an elongation and contraction in the direction at an angle of 45 o relative to the mesogen orientations at the top and bottom surfaces in response to cooling and heating across the nematic–isotropic transition temperature, respectively.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Isotropic-cholesteric transition of a weakly chiral elastomer cylinder.

When a chiral isotropic elastomer is brought to the low-temperature cholesteric phase, the nematic degree of freedom tends to order and form a helix. Due to the nematoelastic coupling, this also leads to elastic deformation of the polymer network that is locally coaxial with the nematic order. However, the helical structure of nematic order is incompatible with the energetically preferred elast...

متن کامل

Polymer-dispersed liquid crystal elastomers

The need for mechanical manipulation during the curing of conventional liquid crystal elastomers diminishes their applicability in the field of shape-programmable soft materials and future applications in additive manufacturing. Here we report on polymer-dispersed liquid crystal elastomers, novel composite materials that eliminate this difficulty. Their thermal shape memory anisotropy is imprin...

متن کامل

Spontaneous shears in smectic elastomers.

We model the spontaneous elastic shear deformations of smectic elastomers as they make the thermal transition between the A and C phases. Tilt of the director is accompanied by shear. Unlike nematic elastomers where spontaneous elongation is associated with changes in the magnitude of order, spontaneous distortion in smectics is instead shear and is associated with rotation of the director of t...

متن کامل

Rotational invariance and Goldstone modes in nematic elastomers and gels

We investigate the symmetries of elastomers and gels cross-linked in a nematic state. The coupling between the local nematic order parameter and an applied deformation leads to a class of uniform deformations which cost no elastic energy, when accompanied by a given rotation of the nematic director; this is a specific realization of a class of soft modes originally proposed, on symmetry argumen...

متن کامل

”Soft elasticity” - deformation without resistance in liquid crystal elastomers

Polymeric nematic liquid crystals crosslinked into elastomers (solid liquid

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2009