Dataset underlying the publication: Going from Inner-Skinned to Outer-Skinned Polyelectrolyte Multilayer Based Hollow Fiber Nanofiltration Membranes

The data is always named after the support membrane that was analyzed. The conditions under which the supports were fabricated including their name can be found in the file "Hollow_Fibre_spinning_conditions_with_Sample_names.csv" included in this folder. In some cases the supports were also coated with polyallylamine hydrochloride (PAH) and sodium polystyrene sulfonate (PSS) or Rhodamine labeled PAH (PAHRho; for the fluorescence spectroscopy samples). In this case the name of the support is followed by the distinction "coated". The type of coating used is specified in either the file or folder name containing the images.<br>Filtration: Contains experimental results of pure water permeability, MgSO4 retention data and 90% molecular weight cut off (MWCO) data based on gel permeation chromatography data (See GPC_data). Measured quantities are: active fiber length (m), average [inlet and outlet] pressure (bar), permeate mass (g) [filled beaker-empty beaker], permeation time (s), hollow fibre outer diameter (mm), feed and permeate conductivity (microS/cm).<br>SEM: SEM images of the different hollow fibres spun. The images are each saved in folders named after the sample that is seen in the image. The conditions under which each sample were fabricated are stated in the article and in the file " Hollow_Fibre_spinning_conditions_with_Sample_names.csv". The magnification at which the images were taken can be seen in the footer of the images. The images within the folders have the following naming convention: 'x_x_type_location#y'<br>Here,- x_x are sample identifiers- type is either "cross" or "surface" indicating a cross-sectional image or top view image respectively.- location is the part of the membrane that has been imaged. This can be "bore", "centre" or "shell", where bore is the inside of the hollow fibre wall, centre the middle of the fibre wall on the cross-sectional images, and shell the outside of the hollow fibre. The "location" is sometimes missing in the filename. This indicates that the entire cross-section of the fibre was imaged.- y is an image identifier when multiple images are taken of a similar location of the same sample<br>GPC_data: This includes the raw GPC data used for determining the MWCO. The data displays signal intensity v.s. molecular weight (g/mol) for the feed solution and permeate solutions of the tested membranes. The solutions contained either polyethylene glycol (PEG) (100-10000 g/mol) for the membranes coated with PAH/PSS or dextrans (18.1-200.000 g/mol) for the uncoated supports.<br>Matlab_scripts: Contains the code used for calculating the pressure drop inside the membrane, loss in transmembrane pressure and increase in membrane surface area compared to commercial geometries as a function of membrane geometry and operational conditions. The explanation of the code is added in comments behind each line of code. The code is provided both in a .m file and a .txt file format and was written using Matlab 2021b.<br>Output_data_model: This folder contains the output data of the model that was plotted in the article that this dataset belongs to. The three files contain: 1) pressure drop data (bar) v.s. bore radius (m) of a fibre. 2) Pressure data (bar) v.s. the location within the fibre bore along the length of the membrane (m). 3)Active membrane surface area increase (as compared to commercial fibres; unitless) v.s. transmembrane pressure loss (TMP_loss; %). All three of these datasets include data for membranes with 5 different ratios between the bore radius and wall thickness of the fibre. All datasets were generated with the input conditions mentioned in the main article.<br>Fluorescence_spectroscopy: This file contains the raw czi data files containing the 40 images made at different focus depths to generate a 3D image. These files can be opened in the freeware software FIJI with which they were converted to 2D overlays. In the 2D overlays the maximum intensity value of the 40 images was saved for each pixel and transposed into a 2D image. These 2D images were saved as PNG files and are also included in the folder.<br>

本数据集始终以所分析的支撑膜命名。支撑膜的制备条件（含其命名规则）可在本文件夹内的"Hollow_Fibre_spinning_conditions_with_Sample_names.csv"文件中查阅。部分支撑膜还经聚烯丙基盐酸胺（polyallylamine hydrochloride, PAH）、聚苯乙烯磺酸钠（sodium polystyrene sulfonate, PSS）或罗丹明标记PAH（PAHRho，仅用于荧光光谱样品）涂层处理，此类样品的支撑膜名称后将追加"coated（涂层）"标识。所用涂层类型可在包含图像的文件或文件夹名称中确认。

过滤实验（Filtration）：包含纯水渗透率、硫酸镁（MgSO₄）截留率数据，以及基于凝胶渗透色谱（gel permeation chromatography, GPC）数据得到的90%截留分子量（molecular weight cut off, MWCO）数据（详见GPC_data文件）。本次测试的量化参数包括：有效纤维长度（m）、进出口平均压力（bar）、渗透液质量（g，即烧杯装满后质量减去空烧杯质量）、渗透时间（s）、中空纤维外径（mm）、进料液与渗透液电导率（microS/cm）。

扫描电子显微镜（scanning electron microscope, SEM）图像：包含不同纺制中空纤维的SEM图像。每张图像均存储于以对应样品命名的文件夹中。各样品的制备条件已在相关论文及"Hollow_Fibre_spinning_conditions_with_Sample_names.csv"文件中说明。图像拍摄倍率可在图片页脚查看。文件夹内图像的命名规则为：`x_x_type_location#y`，其中：
- `x_x`为样品标识符；
- `type`为"cross"（横截面图像）或"surface"（表面俯视图图像）；
- `location`为成像区域，可分为"bore"（中空纤维膜壁内侧）、"centre"（横截面图像中膜壁中部）及"shell"（中空纤维膜外侧），若文件名中未标注`location`，则表示已拍摄纤维的完整横截面；
- `y`为同一样品同一区域多张图像的识别编号。

GPC数据（GPC_data）：包含用于测定MWCO的原始GPC数据，该数据展示了待测膜的进料液与渗透液的信号强度随分子量（g/mol）的变化关系。测试所用溶质分别为：PAH/PSS涂层膜采用聚乙二醇（polyethylene glycol, PEG，分子量范围100~10000 g/mol），未涂层支撑膜采用葡聚糖（dextrans，分子量范围18.1~200000 g/mol）。

Matlab脚本（Matlab_scripts）：包含用于计算膜内压降、跨膜压力损失，以及相较于商用几何结构的膜表面积增幅（基于膜几何结构与操作条件）的代码。代码的详细说明已添加至每行代码后的注释中。本代码同时提供.m格式与.txt格式文件，编写环境为Matlab 2021b。

模型输出数据（Output_data_model）：本文件夹包含本数据集所属论文中绘制的模型输出数据。三个文件分别对应：1）压降（bar）随纤维内径（m）的变化关系；2）压力（bar）沿膜长度方向在纤维内腔中的分布变化关系；3）相较于商用纤维的膜有效表面积增幅（无量纲）随跨膜压力损失（TMP_loss, %）的变化关系。所有数据集均包含5组不同纤维内径与壁厚比值的膜测试数据，且所有数据均基于主论文中提及的输入条件生成。

荧光光谱（Fluorescence_spectroscopy）：本文件夹包含原始czi格式数据文件，其中包含40张不同聚焦深度的图像，用于生成三维图像。这些文件可在免费软件FIJI中打开，且已通过该软件转换为二维叠加图像：二维叠加图像会将40张图像中每个像素的最大强度值提取并转换为二维图像，此类PNG格式的二维图像也已包含在本文件夹中。