Transmission of water through a biocompatible polyurethane: Application to circulatory assist devices

J. Spence Reid, Gerson Rosenberg, William S. Pierce

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The permeability characteristics of a water‐segmented polyurethane (Biomer) system under the conditions encountered in circulatory‐assist devices were investigated. A diffusion cell and permeability system providing precise control of membrane boundary conditions and allowing continuous measurement of water vapor transmission was designed. Liquid water at 37°C was used as the donor fluid and the system incorporated a constant‐flow nitrogen carrier gas and an optical dew point sensor downstream to determine the water vapor mass flow rate as a function of time. The mass flow rate was then numerically integrated and plotted against time to allow calculation of effective diffusion coefficient (D) by the dynamic time lag method. Steady‐state permeabilities were found to be insensitive to donor chamber hydrostatic pressure (50–200 mm Hg) indicating that bulk flow is not a transport mechanism in these membranes. The permeability coefficient (P) was independent of membrane thickness (H) over the four samples tested (0.0102, 0.0148, 0.0269, and 0.0366 cm), with an average value of 3.29 × 10−4cm2/s. Thus, diffusion was Fickian with negligible boundary layers. A plot of lag time versus H2 was linear (R = 0.98) yielding a value for D of 2.18 × 10−7cm2/s. A water–Biomer partition coefficient was determined for each sample with an average value of 1525, indicating a moderately hydrophilic membrane with a water sorption of 6.3% at 37°C. Since water transport is by Fickian diffusion in the absence of bulk flow, liquid water cannot be expected to accumulate in circulatory‐assist devices unless a condensing surface is maintained within the system.

Original languageEnglish (US)
Pages (from-to)1181-1202
Number of pages22
JournalJournal of Biomedical Materials Research
Volume19
Issue number9
DOIs
StatePublished - Jan 1 1985

Fingerprint

Polyurethanes
Membranes
Water
Steam
Water vapor
Flow rate
Hydraulic conductivity
Liquids
Hydrostatic pressure
Sorption
Boundary layers
Nitrogen
Gases
Boundary conditions
Fluids
Sensors

All Science Journal Classification (ASJC) codes

  • Biomaterials
  • Biomedical Engineering

Cite this

@article{8ca4ba48074f4186ab18f3168f16375b,
title = "Transmission of water through a biocompatible polyurethane: Application to circulatory assist devices",
abstract = "The permeability characteristics of a water‐segmented polyurethane (Biomer) system under the conditions encountered in circulatory‐assist devices were investigated. A diffusion cell and permeability system providing precise control of membrane boundary conditions and allowing continuous measurement of water vapor transmission was designed. Liquid water at 37°C was used as the donor fluid and the system incorporated a constant‐flow nitrogen carrier gas and an optical dew point sensor downstream to determine the water vapor mass flow rate as a function of time. The mass flow rate was then numerically integrated and plotted against time to allow calculation of effective diffusion coefficient (D) by the dynamic time lag method. Steady‐state permeabilities were found to be insensitive to donor chamber hydrostatic pressure (50–200 mm Hg) indicating that bulk flow is not a transport mechanism in these membranes. The permeability coefficient (P) was independent of membrane thickness (H) over the four samples tested (0.0102, 0.0148, 0.0269, and 0.0366 cm), with an average value of 3.29 × 10−4cm2/s. Thus, diffusion was Fickian with negligible boundary layers. A plot of lag time versus H2 was linear (R = 0.98) yielding a value for D of 2.18 × 10−7cm2/s. A water–Biomer partition coefficient was determined for each sample with an average value of 1525, indicating a moderately hydrophilic membrane with a water sorption of 6.3{\%} at 37°C. Since water transport is by Fickian diffusion in the absence of bulk flow, liquid water cannot be expected to accumulate in circulatory‐assist devices unless a condensing surface is maintained within the system.",
author = "Reid, {J. Spence} and Gerson Rosenberg and Pierce, {William S.}",
year = "1985",
month = "1",
day = "1",
doi = "10.1002/jbm.820190924",
language = "English (US)",
volume = "19",
pages = "1181--1202",
journal = "Journal of Biomedical Materials Research",
issn = "0021-9304",
publisher = "Heterocorporation",
number = "9",

}

Transmission of water through a biocompatible polyurethane : Application to circulatory assist devices. / Reid, J. Spence; Rosenberg, Gerson; Pierce, William S.

In: Journal of Biomedical Materials Research, Vol. 19, No. 9, 01.01.1985, p. 1181-1202.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Transmission of water through a biocompatible polyurethane

T2 - Application to circulatory assist devices

AU - Reid, J. Spence

AU - Rosenberg, Gerson

AU - Pierce, William S.

PY - 1985/1/1

Y1 - 1985/1/1

N2 - The permeability characteristics of a water‐segmented polyurethane (Biomer) system under the conditions encountered in circulatory‐assist devices were investigated. A diffusion cell and permeability system providing precise control of membrane boundary conditions and allowing continuous measurement of water vapor transmission was designed. Liquid water at 37°C was used as the donor fluid and the system incorporated a constant‐flow nitrogen carrier gas and an optical dew point sensor downstream to determine the water vapor mass flow rate as a function of time. The mass flow rate was then numerically integrated and plotted against time to allow calculation of effective diffusion coefficient (D) by the dynamic time lag method. Steady‐state permeabilities were found to be insensitive to donor chamber hydrostatic pressure (50–200 mm Hg) indicating that bulk flow is not a transport mechanism in these membranes. The permeability coefficient (P) was independent of membrane thickness (H) over the four samples tested (0.0102, 0.0148, 0.0269, and 0.0366 cm), with an average value of 3.29 × 10−4cm2/s. Thus, diffusion was Fickian with negligible boundary layers. A plot of lag time versus H2 was linear (R = 0.98) yielding a value for D of 2.18 × 10−7cm2/s. A water–Biomer partition coefficient was determined for each sample with an average value of 1525, indicating a moderately hydrophilic membrane with a water sorption of 6.3% at 37°C. Since water transport is by Fickian diffusion in the absence of bulk flow, liquid water cannot be expected to accumulate in circulatory‐assist devices unless a condensing surface is maintained within the system.

AB - The permeability characteristics of a water‐segmented polyurethane (Biomer) system under the conditions encountered in circulatory‐assist devices were investigated. A diffusion cell and permeability system providing precise control of membrane boundary conditions and allowing continuous measurement of water vapor transmission was designed. Liquid water at 37°C was used as the donor fluid and the system incorporated a constant‐flow nitrogen carrier gas and an optical dew point sensor downstream to determine the water vapor mass flow rate as a function of time. The mass flow rate was then numerically integrated and plotted against time to allow calculation of effective diffusion coefficient (D) by the dynamic time lag method. Steady‐state permeabilities were found to be insensitive to donor chamber hydrostatic pressure (50–200 mm Hg) indicating that bulk flow is not a transport mechanism in these membranes. The permeability coefficient (P) was independent of membrane thickness (H) over the four samples tested (0.0102, 0.0148, 0.0269, and 0.0366 cm), with an average value of 3.29 × 10−4cm2/s. Thus, diffusion was Fickian with negligible boundary layers. A plot of lag time versus H2 was linear (R = 0.98) yielding a value for D of 2.18 × 10−7cm2/s. A water–Biomer partition coefficient was determined for each sample with an average value of 1525, indicating a moderately hydrophilic membrane with a water sorption of 6.3% at 37°C. Since water transport is by Fickian diffusion in the absence of bulk flow, liquid water cannot be expected to accumulate in circulatory‐assist devices unless a condensing surface is maintained within the system.

UR - http://www.scopus.com/inward/record.url?scp=0022162267&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022162267&partnerID=8YFLogxK

U2 - 10.1002/jbm.820190924

DO - 10.1002/jbm.820190924

M3 - Article

C2 - 4086496

AN - SCOPUS:0022162267

VL - 19

SP - 1181

EP - 1202

JO - Journal of Biomedical Materials Research

JF - Journal of Biomedical Materials Research

SN - 0021-9304

IS - 9

ER -