Characterization of liquid crystal from cellulose nanocrystals

BUFFA, J. M.; MUCCI, V.; ARANGUREN, M. I.

Mar del Plata

Simposio; Simposio Latinoamericano de Polímeros, SLAP 2018; 2018

SLAP 2018

Juan Manuel Buffa, Verónica L. Mucci, Mirta I.Aranguren, ?Characterization of liquid crystal from cellulose nanocrystals?,SLAP 2018, Mar del Plata, 6-9 Noviembre de 2018.Liquid crystals (LCs) are materials that are in liquid statebut have the characteristic long-range order of solid. The order of the systemcan be characterized by rheological measurements, since the response highly dependson the forces between the particles [1]. Cellulose nanocrystals (CNCs) arerod-like particles with lengths between 100 and 300 nm and diameters of 5-10 nm.Due to this high aspect ratio and the chiral nature of the particles (twistednon-cilyndrical rods), at high concentrations (over ~2.5 w/w%) they form chiralnematic LCs [2]. The characterization of LC by rheology relies on the presenceof the so-called signatures: three zones in the 𝜂 (𝛾)̇ curve,long time oscillatory transients, a maximum (or a plateau) in the curve of 𝜂vs. conc., and the Cox-Merz rule is not obeyed. The presence of several ofthese characteristics may be evidence of the LC behavior, although, notnecessarily all of them may appear. <!-- /* Font Definitions */ @font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-536859905 -1073732485 9 0 511 0;}@font-face{font-family:Times;panose-1:2 0 5 0 0 0 0 0 0 0;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 0 0 0 7 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:12.0pt;font-family:Times;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-family:Times;mso-ascii-font-family:Times;mso-fareast-font-family:Calibri;mso-fareast-theme-font:minor-latin;mso-hansi-font-family:Times;mso-bidi-font-family:"Times New Roman";mso-bidi-theme-font:minor-bidi;}size:595.0pt 842.0pt;margin:72.0pt 72.0pt 72.0pt 72.0pt;mso-header-margin:35.45pt;mso-footer-margin:35.45pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}<!-- /* Font Definitions */ @font-face{font-family:Courier;panose-1:2 0 5 0 0 0 0 0 0 0;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 0 0 0 3 0;}@font-face{font-family:"Cambria Math";panose-1:2 4 5 3 5 4 6 3 2 4;mso-font-charset:0;mso-generic-font-family:roman;mso-font-pitch:variable;mso-font-signature:-536870145 1107305727 0 0 415 0;}@font-face{font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;mso-font-charset:0;mso-generic-font-family:swiss;mso-font-pitch:variable;mso-font-signature:-536859905 -1073732485 9 0 511 0;}@font-face{font-family:Times;panose-1:2 0 5 0 0 0 0 0 0 0;mso-font-charset:0;mso-generic-font-family:auto;mso-font-pitch:variable;mso-font-signature:3 0 0 0 7 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal{mso-style-unhide:no;mso-style-qformat:yes;mso-style-parent:"";margin:0cm;margin-bottom:.0001pt;mso-pagination:widow-orphan;font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-font-family:"Times New Roman";}.MsoChpDefault{mso-style-type:export-only;mso-default-props:yes;font-size:10.0pt;mso-ansi-font-size:10.0pt;mso-bidi-font-size:10.0pt;font-family:Courier;mso-ascii-font-family:Courier;mso-fareast-font-family:Courier;mso-hansi-font-family:Courier;}size:612.0pt 792.0pt;margin:72.0pt 72.0pt 72.0pt 72.0pt;mso-header-margin:36.0pt;mso-footer-margin:36.0pt;mso-paper-source:0;}div.WordSection1{page:WordSection1;}mso-level-number-format:roman-lower;mso-level-tab-stop:324.0pt;mso-level-number-position:right;text-indent:-9.0pt;}ol{margin-bottom:0cm;}ul{margin-bottom:0cm;}