水凝胶之间及水凝胶与其他材料之间的粘合，因其在生物医学等新兴领域具有重要的潜在应用价值而受到人们的广泛关注和研究。传统的水凝胶材料表面的黏附性较低，很难实现自身或与其他材料之间的粘合。同时，目前已报道的水凝胶粘合方法大多操作复杂、有毒性且粘合强度不高。本论文工作开发了两种基于非共价相互作用的粘合水凝胶的新方法，实现了水凝胶之间及水凝胶和其他材料之间的高强粘合。

（一）提出了一种主要基于静电作用、操作简便且普适性高的新型水凝胶粘合方法。以带负电的聚丙烯酸（PAA）和带正电的聚乙烯亚胺（PEI）作为粘合剂，将其分别涂抹在聚乙烯醇-聚丙烯酰胺（PVA-PAAm）和聚乙烯基吡咯烷酮-聚丙烯酸（PVP-PAA）两种不同的凝胶表面，然后将涂抹面相对贴合并施压，依靠粘合剂层内产生的静电作用及粘合剂与凝胶网络之间的静电作用和氢键等相互作用使两凝胶之间形成强的粘合。水凝胶的粘合强度受凝胶的组分、放置时间和pH值等的影响。水凝胶的粘合强度随凝胶中AAm含量及在压力下放置时间的增加而增加。在适当的pH（3.0）条件下，PAA与Fe³⁺的预络合可以进一步提高粘合强度。此外，粘合后的凝胶在无压力下放置10天后，粘合强度由粘接初期的560 J/m²增长至2178 J/m²。同时，该粘合方法粘接后的凝胶可以进行多次粘接，三次剥离-粘接后的粘合效率依然高达87%。这一方法也可应用于多种不同水凝胶之间或水凝胶与固体材料、生物组织之间的粘合。

（二）利用PVA-PAAm和PVP-PAA水凝胶之间的氢键作用实现水凝胶之间快速、直接的高强粘合。不借助其他粘合剂，将两种水凝胶直接贴合时，由于其聚合物分子链之间可以迅速形成大量的氢键，5 min内水凝胶的粘合强度即可达到325 J/m²。水凝胶的粘合强度随粘合时间的增加而增加，随凝胶的交联度降低而增加，还随凝胶表面粗糙度增大而增加。证明了氢键作用是凝胶粘合的主要作用。基于氢键作用的水凝胶也可以多次粘合，但粘合效率随重复次数增加而明显降低。此外，两种水凝胶还具有优异的水下粘合性能。即使当水凝胶的含水量分别高达80.6%和88.1%时，二者之间依然可实现在水中的快速粘合。最后，我们还尝试将PVP-PAA水凝胶通过冷冻干燥手段制备成便于保存的粉末状用作固体粘合剂，可以粘合任何可与聚丙烯酸产生氢键的聚合物凝胶。

The adhesion of hydrogels and the adhesion of hydrogels with other materials has drawn rapidly growing attention due to its wide potential applications in emerging fields like biomedicals. However, conventional hydrogels usually have low adhesion to themselves and/or other materials. Currently reported hydrogel adhesion methods are mostly complex, toxic and with low adhesion energies. In this work, two kinds of adhesion methods based on non-covalent interactions are developed and strong adhesions between the hydrogels as well as between the hydrogels and different materials are achieved.

First, a novel, simple and versatile hydrogel adhesion method based on electrostatic interactions has been successfully proposed. Negatively charged polyacrylic acid (PAA) and positively charged polyethyleneimine (PEI) are used as adhesives, and they are separately coated on the surfaces of polyvinyl alcohol-polyacrylamide (PVA-PAAm) and polyvinylpyrrolidone-polyacrylic acid (PVP-PAA) hydrogels, respectively. Then the two surfaces are kept in contact under a pressure. Strong electrostatic interactions, together with other physical interactions like hydrogen bonding and chain entanglement, are formed between the two polyelectrolytes as well as between the two polyelectrolytes and the hydrogels. The adhesion energy of the hydrogels is affected by the component of the hydrogels, adhesion time and pH value. The adhesion energy increases with the increasing content of AAm in the hydrogels and the adhesion time under a pressure. The pre-complexation of PAA and Fe³⁺ at an appropriate pH (3.0) could further increase the adhesion energy. In addition, very impressively, after settling for 10 days without applying a pressure, the adhesion energy of the adhered hydrogel is increased from 560 J/m² to 2178 J/m². Moreover, hydrogels adhered by this method can also be repeatedly adhered, and the adhesion efficiency is as high as 87% after three peeling off-rejoining cycles. This adhesion method can also be applied to the adhesion of other types of hydrogels and adhering hydrogels to other solid materials as well as biological tissues.

Second, a fast, direct and strong adhesion was achieved between PVA-PAAm and PVP-PAA hydrogels through hydrogen bonding. Without using any other adhesives, the two hydrogels are directly adhered and the adhesion energy reaches 325 J/m² in 5 min due to the fast formation hydrogen bonding between the polymer chains in the hydrogels. The adhesion energy increases with the increase of the adhesion time and increases with the decrease of crosslinking degree of the hydrogels, and also increases with the increase of the surface roughness of the hydrogels. It is proved that hydrogen bonding plays the main role in adhering the hydrogels. Adhesion of hydrogels based on hydrogen bonding can also be repeated for several times, but the adhesion efficiency decreases significantly with the increase of repeating times. Furthermore, the hydrogels also have excellent underwater adhesion properties. Even when the water contents of the two kind of hydrogels are as high as 80.6% and 88.1%, they can still achieve fast adhesion. Finally, PVP-PAA hydrogel powders are prepared by freeze-drying method and they are used as solid adhesives. They can strongly adhere hydrogels that can form hydrogen bonding with PAA.