젖은 벽탑을 사용하여 뉴톤액체（PEG 수용액）와 지수법에 일치하는 비뉴톤액체(CMC 수용액)에 CO₂ 기체를 흡수시켜 CO₂의 확산계수를 고분자 분자량 변화에 따라 측정하였다. 확산계수와 용액의 점도와의 관계를 다음과 같은 실험식으로 나타내었다.
25 ℃의 PEG 수용액에 대해서
D = 1.78×10^-5·μ^{-（15.66/Mp0.515）}
20 ℃ CMC수용액에 대해서
D = 1.57×10^-5·μ_app^{（78.18/Mp0.530）}

Diffusion coefficients of CO₂ in aqueous Newtonian solution of PEG（polyethylene glycol） and power-law non-Newtonian solution of CMC (sodium carboxymethyl cellulose) with molecular weights varying from 600 to 8,400 and from 32,300 to 136,800, respectively, were obtained from absorption rate measurements in a wetted-wall column. The diffusivity-viscosity relation is found to be a strong function of the molecular weight of the applied polymers. The data suggest thd following correlations.
For PEG solution at 25 ℃
D = 1.78×10^-5·μ^{-（15.66/Mp0.515）}
For CMC solution at 20℃,
D = 1.57×10^-5·μ_app^{（78.18/Mp0.530）}
The diffusivity of CO₂ in CMC solution was constant with respect to the change of the shear rate at the wall in the studied range of flow rate.