The existence of structure progressions and wetting transitions in intermediately disordered monolayer alkyl chain assemblies

Parikh, Atul N.; Judge, Elizabeth J.

doi:10.1063/1.466604

Cited by 62 publications

(85 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…30 The positions of the a CH 2 or a CH 3 peaks were observed to be constant for all samples at 2921 š 1 cm 1 and 2965 š 1 cm 1 , respectively. The position of the former is consistent with a relatively high degree of conformational order, 38 although not as high as for phosphonic acid monolayers, where a CH 2 was observed at 2917 cm 1 . Orientation of the alkane chains relative to the surface normal may be probed using the relative intensity of the a CH 2 to the a CH 3 bands; for a given alkane chain length, lower a CH 2 / a CH 3 Figure 2.…”

Section: Influence Of Post-deposition Ambient Storage On Stearic Acidsupporting

confidence: 71%

Self‐assembly of stearic acid on aluminium: the importance of oxide surface chemistry

Pertays

Thompson

Alexander

2004

Surface & Interface Analysis

View full text Add to dashboard Cite

The influence of ambient atmospheric exposure on the chemistry of the magnetron-sputtered aluminium surface has been characterized as hydroxyl incorporation to the oxide surface and concurrent adsorption of airborne carbonaceous contamination. Here, the consequence of these changes in oxide surface chemistry upon the adsorption of stearic acid from solution is investigated. Water contact angle and polarization modulation infrared refection-absorption spectroscopy (PM-IRRAS) reveal a strong dependence of stearic acid monolayer order upon ambient exposure time prior to assembly. It is proposed that hydroxyl formation in the ambient atmosphere increases the stearic acid adsorption density and thus the selfassembled monolayer (SAM) order, whereas airborne carbonaceous material blocks these adsorption sites and introduces disorder in the monolayers through a decrease in adsorption density.Monolayer adsorption has been correlated with the aluminium oxide surface chemistry. It is proposed that this phenomenon represents an explanation for the irreproducible results often reported for assembly on metal oxide substrates. Furthermore, it indicates that in this broad class of material surfaces assembly can be used as a means of estimating the reactivity of surfaces with respect to organic overlayers such as paints and adhesives. Removal of adsorbed carbonaceous material from the aluminium surface using an oxygen plasma resulted in a significantly increased order of the stearic acid monolayer, as assessed by water contact angle. This observation is rationalized as the removal of carbonaceous material blocking surface adsorption sites by the plasma, but retention of the underlying hydroxyl functionality. This is predicted to have important implications in the preparation of aluminium for painting and adhesive bonding.

show abstract

Section: Influence Of Post-deposition Ambient Storage On Stearic Acidsupporting

confidence: 71%

Self‐assembly of stearic acid on aluminium: the importance of oxide surface chemistry

Pertays

Thompson

Alexander

2004

Surface & Interface Analysis

View full text Add to dashboard Cite

show abstract

“…16 Using transmission infrared of alkane chains bonded to silica, estimates of the proportion of gauche defects have been made by Allara et al 16 Comparison was made to reflection data from C 22 position of 2917 cm 1 corresponds to 1-4% gauche defects at room temperature. 18 Similarly low (2917-2919 cm 1 ) values are obtained from densely packed monolayers formed from octadecyl trichlorosilane solutions on silica.…”

Section: Polarization Modulation Infrared Reflection-absorption Spectmentioning

confidence: 99%

Comparative study of self‐assembly of a range of monofunctional aliphatic molecules on magnetron‐sputtered aluminium

Liakos

Newman

McAlpine

et al. 2004

Surface & Interface Analysis

View full text Add to dashboard Cite

The adsorption of a range of organic molecules from toluene onto the oxidized surface of magnetronsputtered aluminium metal is studied using sessile drop water contact angle measurements. Molecules with different head group functionalities and various chain lengths are considered, including alkyl carboxylic acids, alkyl phosphonic acids, alkyl amines, alkyl trimethoxysilanes, alkyl trichlorosilanes and epoxy alkanes. Alkyl phosphonic and carboxylic acids are identified as readily forming the most wellpacked monolayers on the aluminium surface, whereas the others adsorb less well and the chlorosilanes polymerize as a result of combination with moisture to form a thick deposit. The high-adsorption-density monolayers of alkyl phosphonic and carboxylic acids were studied using polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and x-ray photoelectron spectroscopy (XPS): PM-IRRAS reveals relatively poorer ordering of the C 10 alkyl carboxylic acid monolayer compared with that formed from the phosphonic acid, and XPS data suggest that this is likely to relate to a lower ability to displace preadsorbed volatile organic compounds.

show abstract

“…We will demonstrate that an increase in the number of methylene spacers in the mercaptoalkanols leads to slower reorganization kinetics and eventual loss of surface switching due to the tendency of these side groups to form semi-crystalline domains at the surface. [33][34][35] PVMS sheets were modified with three different mercaptoalkanols: HS(CH 2 ) 2 OH, HS(CH 2 ) 6 OH, and HS(CH 2 ) 11 OH. In Figure 5 we compare the static contact angle of DI water (u DIW ) as a function of time for each mercaptoalkanol-modified PVMS surface.…”

Section: Tailored Wettability Switching Kinetics and Reconstruction Rmentioning

confidence: 99%

Formation and Properties of Responsive Siloxane‐Based Polymeric Surfaces with Tunable Surface Reconstruction Kinetics

Crowe-Willoughby

Genzer

2009

Adv Funct Materials

View full text Add to dashboard Cite

Here, the formation of responsive polymeric materials with tunable response time is reported. These structures are fabricated by chemically modifying poly(vinylmethyl siloxane) (PVMS) networks with alkanethiols bearing a hydrophilic end‐group (COOH or OH). The response time is facilitated by the liquid nature of the PVMS backbone and increases with increase in length of the methylene spacer (CH2)n in the alkanethiol pendent group. While for n = 2 and 6, the surface reconstructs almost instantaneously, specimens with n = 11 resist reconstruction because of strong van der Waals forces, leading to the formation of semi‐crystalline regions. It is demonstrated that the responsive nature of PVMSS(CH2)11OH can be fine‐tuned by varying the temperature; it possesses a faster response at temperatures above the melting point of the S(CH2)11OH moiety.

show abstract

The existence of structure progressions and wetting transitions in intermediately disordered monolayer alkyl chain assemblies

Cited by 62 publications

References 35 publications

Self‐assembly of stearic acid on aluminium: the importance of oxide surface chemistry

Self‐assembly of stearic acid on aluminium: the importance of oxide surface chemistry

Comparative study of self‐assembly of a range of monofunctional aliphatic molecules on magnetron‐sputtered aluminium

Formation and Properties of Responsive Siloxane‐Based Polymeric Surfaces with Tunable Surface Reconstruction Kinetics

Contact Info

Product

Resources

About